Bump readme (#12305)

Just an is a8de9f0, lack of equals causes cluster_resolver to consider every update a different configuration and restart itself.

Handling NaN should really be prevented with validation, but it looks like that
would lead to yak shaving at the moment.

b/435208946

.github/workflows/branch-testing.yml

@@ -0,0 +1,41 @@
+name: GitHub Actions Branch Testing
+
+on:
+  push:
+    branches:
+    - master
+    - 'v1.*'
+  schedule:
+  - cron: '54 19 * * SUN' # weekly at a "random" time
+
+permissions:
+  contents: read
+
+jobs:
+  arm64:
+    runs-on: ubuntu-24.04-arm
+    strategy:
+      matrix:
+        jre: [17]
+      fail-fast: false # Should swap to true if we grow a large matrix
+
+    steps:
+    - uses: actions/checkout@v4
+    - uses: actions/setup-java@v4
+      with:
+        java-version: ${{ matrix.jre }}
+        distribution: 'temurin'
+
+    - name: Gradle cache
+      uses: actions/cache@v4
+      with:
+        path: |
+          ~/.gradle/caches
+          ~/.gradle/wrapper
+        key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*', '**/gradle-wrapper.properties') }}
+        restore-keys: |
+          ${{ runner.os }}-gradle-
+
+    - name: Build
+      run: ./gradlew -Dorg.gradle.parallel=true -Dorg.gradle.jvmargs='-Xmx1g' -PskipAndroid=true -PskipCodegen=true -PerrorProne=false test
+

.github/workflows/testing.yml

@@ -77,8 +77,11 @@ jobs:
 
   bazel:
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        bzlmod: [true, false]
     env:
-      USE_BAZEL_VERSION: 6.0.0
+      USE_BAZEL_VERSION: 7.0.0
 
     steps:
     - uses: actions/checkout@v4
@@ -97,19 +100,11 @@ jobs:
         key: ${{ runner.os }}-bazel-${{ env.USE_BAZEL_VERSION }}-${{ hashFiles('WORKSPACE', 'repositories.bzl') }}
 
     - name: Run bazel build
-      run: bazelisk build //... --enable_bzlmod=false
+      run: bazelisk build //... --enable_bzlmod=${{ matrix.bzlmod }}
+
+    - name: Run bazel test
+      run: bazelisk test //... --enable_bzlmod=${{ matrix.bzlmod }}
 
     - name: Run example bazel build
-      run: bazelisk build //... --enable_bzlmod=false
-      working-directory: ./examples
-
-    - name: Run bazel build (bzlmod)
-      env:
-        USE_BAZEL_VERSION: 7.0.0
-      run: bazelisk build //... --enable_bzlmod=true
-
-    - name: Run example bazel build (bzlmod)
-      env:
-        USE_BAZEL_VERSION: 7.0.0
-      run: bazelisk build //... --enable_bzlmod=true
+      run: bazelisk build //... --enable_bzlmod=${{ matrix.bzlmod }}
       working-directory: ./examples

BUILD.bazel

@@ -33,7 +33,6 @@ java_library(
         "//api",
         "//protobuf",
         "//stub",
-        "//stub:javax_annotation",
         "@com_google_protobuf//:protobuf_java",
         artifact("com.google.code.findbugs:jsr305"),
         artifact("com.google.guava:guava"),
@@ -47,7 +46,6 @@ java_library(
         "//api",
         "//protobuf-lite",
         "//stub",
-        "//stub:javax_annotation",
         artifact("com.google.code.findbugs:jsr305"),
         artifact("com.google.guava:guava"),
     ],
@@ -67,6 +65,5 @@ java_library(
     visibility = ["//:__subpackages__"],
     exports = [
         artifact("com.google.auto.value:auto-value-annotations"),
-        artifact("org.apache.tomcat:annotations-api"),  # @Generated for Java 9+
     ],
 )

COMPILING.md

@@ -44,11 +44,11 @@ This section is only necessary if you are making changes to the code
 generation. Most users only need to use `skipCodegen=true` as discussed above.
 
 ### Build Protobuf
-The codegen plugin is C++ code and requires protobuf 21.7 or later.
+The codegen plugin is C++ code and requires protobuf 22.5 or later.
 
 For Linux, Mac and MinGW:
 ```
-$ PROTOBUF_VERSION=21.7
+$ PROTOBUF_VERSION=22.5
 $ curl -LO https://github.com/protocolbuffers/protobuf/releases/download/v$PROTOBUF_VERSION/protobuf-all-$PROTOBUF_VERSION.tar.gz
 $ tar xzf protobuf-all-$PROTOBUF_VERSION.tar.gz
 $ cd protobuf-$PROTOBUF_VERSION

MAINTAINERS.md

@@ -11,8 +11,6 @@ for general contribution guidelines.
 - [ejona86](https://github.com/ejona86), Google LLC
 - [jdcormie](https://github.com/jdcormie), Google LLC
 - [kannanjgithub](https://github.com/kannanjgithub), Google LLC
-- [larry-safran](https://github.com/larry-safran), Google LLC
-- [markb74](https://github.com/markb74), Google LLC
 - [ran-su](https://github.com/ran-su), Google LLC
 - [sergiitk](https://github.com/sergiitk), Google LLC
 - [temawi](https://github.com/temawi), Google LLC
@@ -26,7 +24,9 @@ for general contribution guidelines.
 - [ericgribkoff](https://github.com/ericgribkoff)
 - [jiangtaoli2016](https://github.com/jiangtaoli2016)
 - [jtattermusch](https://github.com/jtattermusch)
+- [larry-safran](https://github.com/larry-safran)
 - [louiscryan](https://github.com/louiscryan)
+- [markb74](https://github.com/markb74)
 - [nicolasnoble](https://github.com/nicolasnoble)
 - [nmittler](https://github.com/nmittler)
 - [sanjaypujare](https://github.com/sanjaypujare)

MODULE.bazel

@@ -2,79 +2,61 @@ module(
     name = "grpc-java",
     compatibility_level = 0,
     repo_name = "io_grpc_grpc_java",
-    version = "1.68.0-SNAPSHOT",  # CURRENT_GRPC_VERSION
+    version = "1.76.0-SNAPSHOT",  # CURRENT_GRPC_VERSION
 )
 
 # GRPC_DEPS_START
 IO_GRPC_GRPC_JAVA_ARTIFACTS = [
     "com.google.android:annotations:4.1.1.4",
-    "com.google.api.grpc:proto-google-common-protos:2.29.0",
-    "com.google.auth:google-auth-library-credentials:1.23.0",
-    "com.google.auth:google-auth-library-oauth2-http:1.23.0",
+    "com.google.api.grpc:proto-google-common-protos:2.59.2",
+    "com.google.auth:google-auth-library-credentials:1.24.1",
+    "com.google.auth:google-auth-library-oauth2-http:1.24.1",
     "com.google.auto.value:auto-value-annotations:1.11.0",
     "com.google.auto.value:auto-value:1.11.0",
     "com.google.code.findbugs:jsr305:3.0.2",
     "com.google.code.gson:gson:2.11.0",
-    "com.google.errorprone:error_prone_annotations:2.28.0",
+    "com.google.errorprone:error_prone_annotations:2.30.0",
     "com.google.guava:failureaccess:1.0.1",
-    "com.google.guava:guava:33.2.1-android",
-    "com.google.re2j:re2j:1.7",
+    "com.google.guava:guava:33.3.1-android",
+    "com.google.re2j:re2j:1.8",
+    "com.google.s2a.proto.v2:s2a-proto:0.1.2",
     "com.google.truth:truth:1.4.2",
     "com.squareup.okhttp:okhttp:2.7.5",
     "com.squareup.okio:okio:2.10.0",  # 3.0+ needs swapping to -jvm; need work to avoid flag-day
-    "io.netty:netty-buffer:4.1.110.Final",
-    "io.netty:netty-codec-http2:4.1.110.Final",
-    "io.netty:netty-codec-http:4.1.110.Final",
-    "io.netty:netty-codec-socks:4.1.110.Final",
-    "io.netty:netty-codec:4.1.110.Final",
-    "io.netty:netty-common:4.1.110.Final",
-    "io.netty:netty-handler-proxy:4.1.110.Final",
-    "io.netty:netty-handler:4.1.110.Final",
-    "io.netty:netty-resolver:4.1.110.Final",
-    "io.netty:netty-tcnative-boringssl-static:2.0.65.Final",
-    "io.netty:netty-tcnative-classes:2.0.65.Final",
-    "io.netty:netty-transport-native-epoll:jar:linux-x86_64:4.1.110.Final",
-    "io.netty:netty-transport-native-unix-common:4.1.110.Final",
-    "io.netty:netty-transport:4.1.110.Final",
+    "io.netty:netty-buffer:4.1.124.Final",
+    "io.netty:netty-codec-http2:4.1.124.Final",
+    "io.netty:netty-codec-http:4.1.124.Final",
+    "io.netty:netty-codec-socks:4.1.124.Final",
+    "io.netty:netty-codec:4.1.124.Final",
+    "io.netty:netty-common:4.1.124.Final",
+    "io.netty:netty-handler-proxy:4.1.124.Final",
+    "io.netty:netty-handler:4.1.124.Final",
+    "io.netty:netty-resolver:4.1.124.Final",
+    "io.netty:netty-tcnative-boringssl-static:2.0.70.Final",
+    "io.netty:netty-tcnative-classes:2.0.70.Final",
+    "io.netty:netty-transport-native-epoll:jar:linux-x86_64:4.1.124.Final",
+    "io.netty:netty-transport-native-unix-common:4.1.124.Final",
+    "io.netty:netty-transport:4.1.124.Final",
     "io.opencensus:opencensus-api:0.31.0",
     "io.opencensus:opencensus-contrib-grpc-metrics:0.31.0",
     "io.perfmark:perfmark-api:0.27.0",
     "junit:junit:4.13.2",
-    "org.apache.tomcat:annotations-api:6.0.53",
     "org.checkerframework:checker-qual:3.12.0",
     "org.codehaus.mojo:animal-sniffer-annotations:1.24",
 ]
 # GRPC_DEPS_END
 
+bazel_dep(name = "bazel_jar_jar", version = "0.1.7")
 bazel_dep(name = "bazel_skylib", version = "1.7.1")
 bazel_dep(name = "googleapis", repo_name = "com_google_googleapis", version = "0.0.0-20240326-1c8d509c5")
-# CEL Spec may be removed when cncf/xds MODULE is no longer using protobuf 27.x
-bazel_dep(name = "cel-spec", repo_name = "dev_cel", version = "0.15.0")
-bazel_dep(name = "grpc", repo_name = "com_github_grpc_grpc", version = "1.56.3.bcr.1")
 bazel_dep(name = "grpc-proto", repo_name = "io_grpc_grpc_proto", version = "0.0.0-20240627-ec30f58")
-bazel_dep(name = "protobuf", repo_name = "com_google_protobuf", version = "23.1")
+# Protobuf 25.5+ is incompatible with Bazel 7 with bzlmod
+bazel_dep(name = "protobuf", repo_name = "com_google_protobuf", version = "24.4")
 bazel_dep(name = "rules_cc", version = "0.0.9")
 bazel_dep(name = "rules_java", version = "5.3.5")
-bazel_dep(name = "rules_go", repo_name = "io_bazel_rules_go", version = "0.46.0")
 bazel_dep(name = "rules_jvm_external", version = "6.0")
 bazel_dep(name = "rules_proto", version = "5.3.0-21.7")
 
-non_module_deps = use_extension("//:repositories.bzl", "grpc_java_repositories_extension")
-
-use_repo(
-    non_module_deps,
-    "com_github_cncf_xds",
-    "envoy_api",
-)
-
-grpc_repo_deps_ext = use_extension("@com_github_grpc_grpc//bazel:grpc_deps.bzl", "grpc_repo_deps_ext")
-
-use_repo(
-    grpc_repo_deps_ext,
-    "com_envoyproxy_protoc_gen_validate",
-    "opencensus_proto",
-)
-
 maven = use_extension("@rules_jvm_external//:extensions.bzl", "maven")
 
 maven.install(
@@ -201,7 +183,3 @@ maven.override(
     coordinates = "io.grpc:grpc-util",
     target = "@io_grpc_grpc_java//util",
 )
-
-switched_rules = use_extension("@com_google_googleapis//:extensions.bzl", "switched_rules")
-
-switched_rules.use_languages(java = True)

README.md

@@ -44,8 +44,8 @@ For a guided tour, take a look at the [quick start
 guide](https://grpc.io/docs/languages/java/quickstart) or the more explanatory [gRPC
 basics](https://grpc.io/docs/languages/java/basics).
 
-The [examples](https://github.com/grpc/grpc-java/tree/v1.67.1/examples) and the
-[Android example](https://github.com/grpc/grpc-java/tree/v1.67.1/examples/android)
+The [examples](https://github.com/grpc/grpc-java/tree/v1.75.0/examples) and the
+[Android example](https://github.com/grpc/grpc-java/tree/v1.75.0/examples/android)
 are standalone projects that showcase the usage of gRPC.
 
 Download
@@ -56,18 +56,18 @@ Download [the JARs][]. Or for Maven with non-Android, add to your `pom.xml`:
 <dependency>
   <groupId>io.grpc</groupId>
   <artifactId>grpc-netty-shaded</artifactId>
-  <version>1.67.1</version>
+  <version>1.75.0</version>
   <scope>runtime</scope>
 </dependency>
 <dependency>
   <groupId>io.grpc</groupId>
   <artifactId>grpc-protobuf</artifactId>
-  <version>1.67.1</version>
+  <version>1.75.0</version>
 </dependency>
 <dependency>
   <groupId>io.grpc</groupId>
   <artifactId>grpc-stub</artifactId>
-  <version>1.67.1</version>
+  <version>1.75.0</version>
 </dependency>
 <dependency> <!-- necessary for Java 9+ -->
   <groupId>org.apache.tomcat</groupId>
@@ -79,18 +79,18 @@ Download [the JARs][]. Or for Maven with non-Android, add to your `pom.xml`:
 
 Or for Gradle with non-Android, add to your dependencies:
 ```gradle
-runtimeOnly 'io.grpc:grpc-netty-shaded:1.67.1'
-implementation 'io.grpc:grpc-protobuf:1.67.1'
-implementation 'io.grpc:grpc-stub:1.67.1'
+runtimeOnly 'io.grpc:grpc-netty-shaded:1.75.0'
+implementation 'io.grpc:grpc-protobuf:1.75.0'
+implementation 'io.grpc:grpc-stub:1.75.0'
 compileOnly 'org.apache.tomcat:annotations-api:6.0.53' // necessary for Java 9+
 ```
 
 For Android client, use `grpc-okhttp` instead of `grpc-netty-shaded` and
 `grpc-protobuf-lite` instead of `grpc-protobuf`:
 ```gradle
-implementation 'io.grpc:grpc-okhttp:1.67.1'
-implementation 'io.grpc:grpc-protobuf-lite:1.67.1'
-implementation 'io.grpc:grpc-stub:1.67.1'
+implementation 'io.grpc:grpc-okhttp:1.75.0'
+implementation 'io.grpc:grpc-protobuf-lite:1.75.0'
+implementation 'io.grpc:grpc-stub:1.75.0'
 compileOnly 'org.apache.tomcat:annotations-api:6.0.53' // necessary for Java 9+
 ```
 
@@ -99,10 +99,10 @@ For [Bazel](https://bazel.build), you can either
 (with the GAVs from above), or use `@io_grpc_grpc_java//api` et al (see below).
 
 [the JARs]:
-https://search.maven.org/search?q=g:io.grpc%20AND%20v:1.67.1
+https://search.maven.org/search?q=g:io.grpc%20AND%20v:1.75.0
 
 Development snapshots are available in [Sonatypes's snapshot
-repository](https://oss.sonatype.org/content/repositories/snapshots/).
+repository](https://central.sonatype.com/repository/maven-snapshots/).
 
 Generated Code
 --------------
@@ -129,9 +129,9 @@ For protobuf-based codegen integrated with the Maven build system, you can use
       <artifactId>protobuf-maven-plugin</artifactId>
       <version>0.6.1</version>
       <configuration>
-        <protocArtifact>com.google.protobuf:protoc:3.25.3:exe:${os.detected.classifier}</protocArtifact>
+        <protocArtifact>com.google.protobuf:protoc:3.25.5:exe:${os.detected.classifier}</protocArtifact>
         <pluginId>grpc-java</pluginId>
-        <pluginArtifact>io.grpc:protoc-gen-grpc-java:1.67.1:exe:${os.detected.classifier}</pluginArtifact>
+        <pluginArtifact>io.grpc:protoc-gen-grpc-java:1.75.0:exe:${os.detected.classifier}</pluginArtifact>
       </configuration>
       <executions>
         <execution>
@@ -152,16 +152,16 @@ For non-Android protobuf-based codegen integrated with the Gradle build system,
 you can use [protobuf-gradle-plugin][]:
 ```gradle
 plugins {
-    id 'com.google.protobuf' version '0.9.4'
+    id 'com.google.protobuf' version '0.9.5'
 }
 
 protobuf {
   protoc {
-    artifact = "com.google.protobuf:protoc:3.25.3"
+    artifact = "com.google.protobuf:protoc:3.25.5"
   }
   plugins {
     grpc {
-      artifact = 'io.grpc:protoc-gen-grpc-java:1.67.1'
+      artifact = 'io.grpc:protoc-gen-grpc-java:1.75.0'
     }
   }
   generateProtoTasks {
@@ -185,16 +185,16 @@ use protobuf-gradle-plugin but specify the 'lite' options:
 
 ```gradle
 plugins {
-    id 'com.google.protobuf' version '0.9.4'
+    id 'com.google.protobuf' version '0.9.5'
 }
 
 protobuf {
   protoc {
-    artifact = "com.google.protobuf:protoc:3.25.3"
+    artifact = "com.google.protobuf:protoc:3.25.5"
   }
   plugins {
     grpc {
-      artifact = 'io.grpc:protoc-gen-grpc-java:1.67.1'
+      artifact = 'io.grpc:protoc-gen-grpc-java:1.75.0'
     }
   }
   generateProtoTasks {

RELEASING.md

@@ -160,21 +160,21 @@ Tagging the Release
    repository can then be `released`, which will begin the process of pushing
    the new artifacts to Maven Central (the staging repository will be destroyed
    in the process). You can see the complete process for releasing to Maven
-   Central on the [OSSRH site](https://central.sonatype.org/pages/releasing-the-deployment.html).
+   Central on the [OSSRH site](https://central.sonatype.org/publish/publish-portal-ossrh-staging-api/#deploying).
 
 10. We have containers for each release to detect compatibility regressions with
     old releases. Generate one for the new release by following the [GCR image
     generation instructions][gcr-image]. Summary:
     ```bash
     # If you haven't previously configured docker:
-    gcloud auth configure-docker
+    gcloud auth configure-docker us-docker.pkg.dev
 
     # In main grpc repo, add the new version to matrix
     ${EDITOR:-nano -w} tools/interop_matrix/client_matrix.py
     tools/interop_matrix/create_matrix_images.py --git_checkout --release=v$MAJOR.$MINOR.$PATCH \
         --upload_images --language java
-    docker pull gcr.io/grpc-testing/grpc_interop_java:v$MAJOR.$MINOR.$PATCH
-    docker_image=gcr.io/grpc-testing/grpc_interop_java:v$MAJOR.$MINOR.$PATCH \
+    docker pull us-docker.pkg.dev/grpc-testing/testing-images-public/grpc_interop_java:v$MAJOR.$MINOR.$PATCH
+    docker_image=us-docker.pkg.dev/grpc-testing/testing-images-public/grpc_interop_java:v$MAJOR.$MINOR.$PATCH \
         tools/interop_matrix/testcases/java__master
 
     # Commit the changes

SECURITY.md

@@ -399,7 +399,9 @@ grpc-netty version | netty-handler version | netty-tcnative-boringssl-static ver
 1.57.x-1.58.x      | 4.1.93.Final          | 2.0.61.Final
 1.59.x             | 4.1.97.Final          | 2.0.61.Final
 1.60.x-1.66.x      | 4.1.100.Final         | 2.0.61.Final
-1.67.x             | 4.1.110.Final         | 2.0.65.Final
+1.67.x-1.70.x      | 4.1.110.Final         | 2.0.65.Final
+1.71.x-1.74.x      | 4.1.110.Final         | 2.0.70.Final
+1.75.x-            | 4.1.124.Final         | 2.0.72.Final
 
 _(grpc-netty-shaded avoids issues with keeping these versions in sync.)_
 

WORKSPACE

@@ -22,20 +22,19 @@ load("//:repositories.bzl", "grpc_java_repositories")
 
 grpc_java_repositories()
 
+load("@bazel_jar_jar//:jar_jar.bzl", "jar_jar_repositories")
+
+jar_jar_repositories()
+
 load("@com_google_protobuf//:protobuf_deps.bzl", "PROTOBUF_MAVEN_ARTIFACTS")
 load("@com_google_protobuf//:protobuf_deps.bzl", "protobuf_deps")
 
 protobuf_deps()
 
-load("@envoy_api//bazel:repositories.bzl", "api_dependencies")
-
-api_dependencies()
-
 load("@com_google_googleapis//:repository_rules.bzl", "switched_rules_by_language")
 
 switched_rules_by_language(
     name = "com_google_googleapis_imports",
-    java = True,
 )
 
 maven_install(

alts/BUILD.bazel

@@ -18,6 +18,7 @@ java_library(
         "@com_google_protobuf//:protobuf_java",
         "@com_google_protobuf//:protobuf_java_util",
         artifact("com.google.code.findbugs:jsr305"),
+        artifact("com.google.errorprone:error_prone_annotations"),
         artifact("com.google.guava:guava"),
         artifact("io.netty:netty-buffer"),
         artifact("io.netty:netty-codec"),

alts/build.gradle

@@ -2,8 +2,8 @@ plugins {
     id "java-library"
     id "maven-publish"
 
-    id "com.github.johnrengelman.shadow"
     id "com.google.protobuf"
+    id "com.gradleup.shadow"
     id "ru.vyarus.animalsniffer"
 }
 
@@ -44,7 +44,11 @@ dependencies {
             classifier = "linux-x86_64"
         }
     }
-    signature libraries.signature.java
+    signature (libraries.signature.java) {
+        artifact {
+            extension = "signature"
+        }
+    }
 }
 
 configureProtoCompilation()

alts/src/generated/main/grpc/io/grpc/alts/internal/HandshakerServiceGrpc.java

@@ -4,9 +4,6 @@ import static io.grpc.MethodDescriptor.generateFullMethodName;
 
 /**
  */
-@javax.annotation.Generated(
-    value = "by gRPC proto compiler",
-    comments = "Source: grpc/gcp/handshaker.proto")
 @io.grpc.stub.annotations.GrpcGenerated
 public final class HandshakerServiceGrpc {
 
@@ -60,6 +57,21 @@ public final class HandshakerServiceGrpc {
     return HandshakerServiceStub.newStub(factory, channel);
   }
 
+  /**
+   * Creates a new blocking-style stub that supports all types of calls on the service
+   */
+  public static HandshakerServiceBlockingV2Stub newBlockingV2Stub(
+      io.grpc.Channel channel) {
+    io.grpc.stub.AbstractStub.StubFactory<HandshakerServiceBlockingV2Stub> factory =
+      new io.grpc.stub.AbstractStub.StubFactory<HandshakerServiceBlockingV2Stub>() {
+        @java.lang.Override
+        public HandshakerServiceBlockingV2Stub newStub(io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+          return new HandshakerServiceBlockingV2Stub(channel, callOptions);
+        }
+      };
+    return HandshakerServiceBlockingV2Stub.newStub(factory, channel);
+  }
+
   /**
    * Creates a new blocking-style stub that supports unary and streaming output calls on the service
    */
@@ -157,6 +169,40 @@ public final class HandshakerServiceGrpc {
   /**
    * A stub to allow clients to do synchronous rpc calls to service HandshakerService.
    */
+  public static final class HandshakerServiceBlockingV2Stub
+      extends io.grpc.stub.AbstractBlockingStub<HandshakerServiceBlockingV2Stub> {
+    private HandshakerServiceBlockingV2Stub(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      super(channel, callOptions);
+    }
+
+    @java.lang.Override
+    protected HandshakerServiceBlockingV2Stub build(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      return new HandshakerServiceBlockingV2Stub(channel, callOptions);
+    }
+
+    /**
+     * <pre>
+     * Handshaker service accepts a stream of handshaker request, returning a
+     * stream of handshaker response. Client is expected to send exactly one
+     * message with either client_start or server_start followed by one or more
+     * messages with next. Each time client sends a request, the handshaker
+     * service expects to respond. Client does not have to wait for service's
+     * response before sending next request.
+     * </pre>
+     */
+    @io.grpc.ExperimentalApi("https://github.com/grpc/grpc-java/issues/10918")
+    public io.grpc.stub.BlockingClientCall<io.grpc.alts.internal.HandshakerReq, io.grpc.alts.internal.HandshakerResp>
+        doHandshake() {
+      return io.grpc.stub.ClientCalls.blockingBidiStreamingCall(
+          getChannel(), getDoHandshakeMethod(), getCallOptions());
+    }
+  }
+
+  /**
+   * A stub to allow clients to do limited synchronous rpc calls to service HandshakerService.
+   */
   public static final class HandshakerServiceBlockingStub
       extends io.grpc.stub.AbstractBlockingStub<HandshakerServiceBlockingStub> {
     private HandshakerServiceBlockingStub(

alts/src/main/java/io/grpc/alts/AltsContextUtil.java

@@ -14,9 +14,10 @@
  * limitations under the License.
  */
 
-
 package io.grpc.alts;
 
+import io.grpc.Attributes;
+import io.grpc.ClientCall;
 import io.grpc.ExperimentalApi;
 import io.grpc.ServerCall;
 import io.grpc.alts.internal.AltsInternalContext;
@@ -29,14 +30,36 @@ public final class AltsContextUtil {
   private AltsContextUtil() {}
 
   /**
-   * Creates a {@link AltsContext} from ALTS context information in the {@link ServerCall}.
+   * Creates an {@link AltsContext} from ALTS context information in the {@link ServerCall}.
    *
    * @param call the {@link ServerCall} containing the ALTS information
    * @return the created {@link AltsContext}
    * @throws IllegalArgumentException if the {@link ServerCall} has no ALTS information.
    */
-  public static AltsContext createFrom(ServerCall<?,?> call) {
-    Object authContext = call.getAttributes().get(AltsProtocolNegotiator.AUTH_CONTEXT_KEY);
+  public static AltsContext createFrom(ServerCall<?, ?> call) {
+    return createFrom(call.getAttributes());
+  }
+
+  /**
+   * Creates an {@link AltsContext} from ALTS context information in the {@link ClientCall}.
+   *
+   * @param call the {@link ClientCall} containing the ALTS information
+   * @return the created {@link AltsContext}
+   * @throws IllegalArgumentException if the {@link ClientCall} has no ALTS information.
+   */
+  public static AltsContext createFrom(ClientCall<?, ?> call) {
+    return createFrom(call.getAttributes());
+  }
+
+  /**
+   * Creates an {@link AltsContext} from ALTS context information in the {@link Attributes}.
+   *
+   * @param attributes the {@link Attributes} containing the ALTS information
+   * @return the created {@link AltsContext}
+   * @throws IllegalArgumentException if the {@link Attributes} has no ALTS information.
+   */
+  public static AltsContext createFrom(Attributes attributes) {
+    Object authContext = attributes.get(AltsProtocolNegotiator.AUTH_CONTEXT_KEY);
     if (!(authContext instanceof AltsInternalContext)) {
       throw new IllegalArgumentException("No ALTS context information found");
     }
@@ -49,8 +72,28 @@ public final class AltsContextUtil {
    * @param call the {@link ServerCall} to check
    * @return true, if the {@link ServerCall} contains ALTS information and false otherwise.
    */
-  public static boolean check(ServerCall<?,?> call) {
-    Object authContext = call.getAttributes().get(AltsProtocolNegotiator.AUTH_CONTEXT_KEY);
+  public static boolean check(ServerCall<?, ?> call) {
+    return check(call.getAttributes());
+  }
+
+  /**
+   * Checks if the {@link ClientCall} contains ALTS information.
+   *
+   * @param call the {@link ClientCall} to check
+   * @return true, if the {@link ClientCall} contains ALTS information and false otherwise.
+   */
+  public static boolean check(ClientCall<?, ?> call) {
+    return check(call.getAttributes());
+  }
+
+  /**
+   * Checks if the {@link Attributes} contains ALTS information.
+   *
+   * @param attributes the {@link Attributes} to check
+   * @return true, if the {@link Attributes} contains ALTS information and false otherwise.
+   */
+  public static boolean check(Attributes attributes) {
+    Object authContext = attributes.get(AltsProtocolNegotiator.AUTH_CONTEXT_KEY);
     return authContext instanceof AltsInternalContext;
   }
 }

alts/src/main/java/io/grpc/alts/DualCallCredentials.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2024 The gRPC Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.grpc.alts;
+
+import io.grpc.CallCredentials;
+import java.util.concurrent.Executor;
+
+/**
+ * {@code CallCredentials} that will pick the right credentials based on whether the established
+ * connection is ALTS or TLS.
+ */
+final class DualCallCredentials extends CallCredentials {
+  private final CallCredentials tlsCallCredentials;
+  private final CallCredentials altsCallCredentials;
+
+  public DualCallCredentials(CallCredentials tlsCallCreds, CallCredentials altsCallCreds) {
+    tlsCallCredentials = tlsCallCreds;
+    altsCallCredentials = altsCallCreds;
+  }
+
+  @Override
+  public void applyRequestMetadata(
+      CallCredentials.RequestInfo requestInfo,
+      Executor appExecutor,
+      CallCredentials.MetadataApplier applier) {
+    if (AltsContextUtil.check(requestInfo.getTransportAttrs())) {
+      altsCallCredentials.applyRequestMetadata(requestInfo, appExecutor, applier);
+    } else {
+      tlsCallCredentials.applyRequestMetadata(requestInfo, appExecutor, applier);
+    }
+  }
+}

alts/src/main/java/io/grpc/alts/GoogleDefaultChannelCredentials.java

@@ -63,6 +63,7 @@ public final class GoogleDefaultChannelCredentials {
    */
   public static final class Builder {
     private CallCredentials callCredentials;
+    private CallCredentials altsCallCredentials;
 
     private Builder() {}
 
@@ -72,23 +73,32 @@ public final class GoogleDefaultChannelCredentials {
       return this;
     }
 
+    /** Constructs GoogleDefaultChannelCredentials with an ALTS-specific call credential. */
+    public Builder altsCallCredentials(CallCredentials callCreds) {
+      altsCallCredentials = callCreds;
+      return this;
+    }
+
     /** Builds a GoogleDefaultChannelCredentials instance. */
     public ChannelCredentials build() {
       ChannelCredentials nettyCredentials =
           InternalNettyChannelCredentials.create(createClientFactory());
-      if (callCredentials != null) {
-        return CompositeChannelCredentials.create(nettyCredentials, callCredentials);
-      }
-      CallCredentials callCreds;
-      try {
-        callCreds = MoreCallCredentials.from(GoogleCredentials.getApplicationDefault());
-      } catch (IOException e) {
-        callCreds =
-            new FailingCallCredentials(
-                Status.UNAUTHENTICATED
-                    .withDescription("Failed to get Google default credentials")
-                    .withCause(e));
+      CallCredentials tlsCallCreds = callCredentials;
+      if (tlsCallCreds == null) {
+        try {
+          tlsCallCreds = MoreCallCredentials.from(GoogleCredentials.getApplicationDefault());
+        } catch (IOException e) {
+          tlsCallCreds =
+              new FailingCallCredentials(
+                  Status.UNAUTHENTICATED
+                      .withDescription("Failed to get Google default credentials")
+                      .withCause(e));
+        }
       }
+      CallCredentials callCreds =
+          altsCallCredentials == null
+              ? tlsCallCreds
+              : new DualCallCredentials(tlsCallCreds, altsCallCredentials);
       return CompositeChannelCredentials.create(nettyCredentials, callCreds);
     }
 

alts/src/main/java/io/grpc/alts/HandshakerServiceChannel.java

@@ -21,6 +21,7 @@ import io.grpc.Channel;
 import io.grpc.ClientCall;
 import io.grpc.ManagedChannel;
 import io.grpc.MethodDescriptor;
+import io.grpc.internal.GrpcUtil;
 import io.grpc.internal.SharedResourceHolder.Resource;
 import io.grpc.netty.NettyChannelBuilder;
 import io.netty.channel.EventLoopGroup;
@@ -45,6 +46,9 @@ final class HandshakerServiceChannel {
     return new ChannelResource(handshakerAddress);
   }
 
+  private static final boolean EXPERIMENTAL_ALTS_HANDSHAKER_KEEPALIVE_PARAMS =
+      GrpcUtil.getFlag("GRPC_EXPERIMENTAL_ALTS_HANDSHAKER_KEEPALIVE_PARAMS", false);
+
   private static class ChannelResource implements Resource<Channel> {
     private final String target;
 
@@ -57,12 +61,16 @@ final class HandshakerServiceChannel {
       /* Use its own event loop thread pool to avoid blocking. */
       EventLoopGroup eventGroup =
           new NioEventLoopGroup(1, new DefaultThreadFactory("handshaker pool", true));
-      ManagedChannel channel = NettyChannelBuilder.forTarget(target)
+      NettyChannelBuilder channelBuilder =
+          NettyChannelBuilder.forTarget(target)
           .channelType(NioSocketChannel.class, InetSocketAddress.class)
           .directExecutor()
           .eventLoopGroup(eventGroup)
-          .usePlaintext()
-          .build();
+          .usePlaintext();
+      if (EXPERIMENTAL_ALTS_HANDSHAKER_KEEPALIVE_PARAMS) {
+        channelBuilder.keepAliveTime(10, TimeUnit.MINUTES).keepAliveTimeout(10, TimeUnit.SECONDS);
+      }
+      ManagedChannel channel = channelBuilder.build();
       return new EventLoopHoldingChannel(channel, eventGroup);
     }
 

alts/src/main/java/io/grpc/alts/internal/AsyncSemaphore.java

@@ -16,12 +16,12 @@
 
 package io.grpc.alts.internal;
 
+import com.google.errorprone.annotations.concurrent.GuardedBy;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelPromise;
 import java.util.LinkedList;
 import java.util.Queue;
-import javax.annotation.concurrent.GuardedBy;
 
 /** Provides a semaphore primitive, without blocking waiting on permits. */
 final class AsyncSemaphore {

alts/src/test/java/io/grpc/alts/AltsContextUtilTest.java

@@ -24,6 +24,7 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 import io.grpc.Attributes;
+import io.grpc.ClientCall;
 import io.grpc.ServerCall;
 import io.grpc.alts.AltsContext.SecurityLevel;
 import io.grpc.alts.internal.AltsInternalContext;
@@ -37,27 +38,28 @@ import org.junit.runners.JUnit4;
 /** Unit tests for {@link AltsContextUtil}. */
 @RunWith(JUnit4.class)
 public class AltsContextUtilTest {
-
-  private final ServerCall<?,?> call = mock(ServerCall.class);
-
   @Test
   public void check_noAttributeValue() {
-    when(call.getAttributes()).thenReturn(Attributes.newBuilder().build());
-
-    assertFalse(AltsContextUtil.check(call));
+    assertFalse(AltsContextUtil.check(Attributes.newBuilder().build()));
   }
 
   @Test
-  public void contains_unexpectedAttributeValueType() {
-    when(call.getAttributes()).thenReturn(Attributes.newBuilder()
+  public void check_unexpectedAttributeValueType() {
+    assertFalse(AltsContextUtil.check(Attributes.newBuilder()
         .set(AltsProtocolNegotiator.AUTH_CONTEXT_KEY, new Object())
-        .build());
-
-    assertFalse(AltsContextUtil.check(call));
+        .build()));
   }
 
   @Test
-  public void contains_altsInternalContext() {
+  public void check_altsInternalContext() {
+    assertTrue(AltsContextUtil.check(Attributes.newBuilder()
+        .set(AltsProtocolNegotiator.AUTH_CONTEXT_KEY, AltsInternalContext.getDefaultInstance())
+        .build()));
+  }
+
+  @Test
+  public void checkServer_altsInternalContext() {
+    ServerCall<?,?> call = mock(ServerCall.class);
     when(call.getAttributes()).thenReturn(Attributes.newBuilder()
         .set(AltsProtocolNegotiator.AUTH_CONTEXT_KEY, AltsInternalContext.getDefaultInstance())
         .build());
@@ -66,26 +68,67 @@ public class AltsContextUtilTest {
   }
 
   @Test
-  public void from_altsInternalContext() {
+  public void checkClient_altsInternalContext() {
+    ClientCall<?,?> call = mock(ClientCall.class);
+    when(call.getAttributes()).thenReturn(Attributes.newBuilder()
+        .set(AltsProtocolNegotiator.AUTH_CONTEXT_KEY, AltsInternalContext.getDefaultInstance())
+        .build());
+
+    assertTrue(AltsContextUtil.check(call));
+  }
+
+  @Test
+  public void createFrom_altsInternalContext() {
     HandshakerResult handshakerResult =
         HandshakerResult.newBuilder()
             .setPeerIdentity(Identity.newBuilder().setServiceAccount("remote@peer"))
             .setLocalIdentity(Identity.newBuilder().setServiceAccount("local@peer"))
             .build();
-    when(call.getAttributes()).thenReturn(Attributes.newBuilder()
-        .set(AltsProtocolNegotiator.AUTH_CONTEXT_KEY,  new AltsInternalContext(handshakerResult))
-        .build());
 
-    AltsContext context = AltsContextUtil.createFrom(call);
+    AltsContext context = AltsContextUtil.createFrom(Attributes.newBuilder()
+        .set(AltsProtocolNegotiator.AUTH_CONTEXT_KEY, new AltsInternalContext(handshakerResult))
+        .build());
     assertEquals("remote@peer", context.getPeerServiceAccount());
     assertEquals("local@peer", context.getLocalServiceAccount());
     assertEquals(SecurityLevel.INTEGRITY_AND_PRIVACY, context.getSecurityLevel());
   }
 
   @Test(expected = IllegalArgumentException.class)
-  public void from_noAttributeValue() {
-    when(call.getAttributes()).thenReturn(Attributes.newBuilder().build());
+  public void createFrom_noAttributeValue() {
+    AltsContextUtil.createFrom(Attributes.newBuilder().build());
+  }
 
-    AltsContextUtil.createFrom(call);
+  @Test
+  public void createFromServer_altsInternalContext() {
+    HandshakerResult handshakerResult =
+        HandshakerResult.newBuilder()
+            .setPeerIdentity(Identity.newBuilder().setServiceAccount("remote@peer"))
+            .setLocalIdentity(Identity.newBuilder().setServiceAccount("local@peer"))
+            .build();
+
+    ServerCall<?,?> call = mock(ServerCall.class);
+    when(call.getAttributes()).thenReturn(Attributes.newBuilder()
+        .set(AltsProtocolNegotiator.AUTH_CONTEXT_KEY, new AltsInternalContext(handshakerResult))
+        .build());
+
+    AltsContext context = AltsContextUtil.createFrom(call);
+    assertEquals("remote@peer", context.getPeerServiceAccount());
+  }
+
+  @Test
+  public void createFromClient_altsInternalContext() {
+    HandshakerResult handshakerResult =
+        HandshakerResult.newBuilder()
+            .setPeerIdentity(Identity.newBuilder().setServiceAccount("remote@peer"))
+            .setLocalIdentity(Identity.newBuilder().setServiceAccount("local@peer"))
+            .build();
+
+    ClientCall<?,?> call = mock(ClientCall.class);
+    when(call.getAttributes()).thenReturn(Attributes.newBuilder()
+        .set(AltsProtocolNegotiator.AUTH_CONTEXT_KEY, new AltsInternalContext(handshakerResult))
+        .build());
+
+    AltsContext context = AltsContextUtil.createFrom(call);
+    assertEquals("remote@peer", context.getPeerServiceAccount());
   }
 }

alts/src/test/java/io/grpc/alts/DualCallCredentialsTest.java

@@ -0,0 +1,109 @@
+/*
+ * Copyright 2024 The gRPC Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.grpc.alts;
+
+import static org.mockito.Mockito.any;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+import io.grpc.Attributes;
+import io.grpc.CallCredentials;
+import io.grpc.CallCredentials.RequestInfo;
+import io.grpc.MethodDescriptor;
+import io.grpc.SecurityLevel;
+import io.grpc.alts.internal.AltsInternalContext;
+import io.grpc.alts.internal.AltsProtocolNegotiator;
+import io.grpc.testing.TestMethodDescriptors;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnit;
+import org.mockito.junit.MockitoRule;
+
+/** Unit tests for {@link DualCallCredentials}. */
+@RunWith(JUnit4.class)
+public class DualCallCredentialsTest {
+
+  @Rule public final MockitoRule mocks = MockitoJUnit.rule();
+
+  @Mock CallCredentials tlsCallCredentials;
+
+  @Mock CallCredentials altsCallCredentials;
+
+  private static final String AUTHORITY = "testauthority";
+  private static final SecurityLevel SECURITY_LEVEL = SecurityLevel.PRIVACY_AND_INTEGRITY;
+
+  @Test
+  public void invokeTlsCallCredentials() {
+    DualCallCredentials callCredentials =
+        new DualCallCredentials(tlsCallCredentials, altsCallCredentials);
+    RequestInfo requestInfo = new RequestInfoImpl(false);
+    callCredentials.applyRequestMetadata(requestInfo, null, null);
+
+    verify(altsCallCredentials, never()).applyRequestMetadata(any(), any(), any());
+    verify(tlsCallCredentials, times(1)).applyRequestMetadata(requestInfo, null, null);
+  }
+
+  @Test
+  public void invokeAltsCallCredentials() {
+    DualCallCredentials callCredentials =
+        new DualCallCredentials(tlsCallCredentials, altsCallCredentials);
+    RequestInfo requestInfo = new RequestInfoImpl(true);
+    callCredentials.applyRequestMetadata(requestInfo, null, null);
+
+    verify(altsCallCredentials, times(1)).applyRequestMetadata(requestInfo, null, null);
+    verify(tlsCallCredentials, never()).applyRequestMetadata(any(), any(), any());
+  }
+
+  private static final class RequestInfoImpl extends CallCredentials.RequestInfo {
+    private Attributes attrs;
+
+    RequestInfoImpl(boolean hasAltsContext) {
+      attrs =
+          hasAltsContext
+              ? Attributes.newBuilder()
+                  .set(
+                      AltsProtocolNegotiator.AUTH_CONTEXT_KEY,
+                      AltsInternalContext.getDefaultInstance())
+                  .build()
+              : Attributes.EMPTY;
+    }
+
+    @Override
+    public MethodDescriptor<?, ?> getMethodDescriptor() {
+      return TestMethodDescriptors.voidMethod();
+    }
+
+    @Override
+    public SecurityLevel getSecurityLevel() {
+      return SECURITY_LEVEL;
+    }
+
+    @Override
+    public String getAuthority() {
+      return AUTHORITY;
+    }
+
+    @Override
+    public Attributes getTransportAttrs() {
+      return attrs;
+    }
+  }
+}

android-interop-testing/build.gradle

@@ -7,11 +7,10 @@ description = 'gRPC: Android Integration Testing'
 
 repositories {
     google()
-    mavenCentral()
 }
 
 android {
-    namespace 'io.grpc.android.integrationtest'
+    namespace = 'io.grpc.android.integrationtest'
     sourceSets {
         main {
             java {
@@ -42,7 +41,7 @@ android {
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
-        multiDexEnabled true
+        multiDexEnabled = true
     }
     buildTypes {
         debug { minifyEnabled false }
@@ -74,7 +73,6 @@ dependencies {
             project(':grpc-protobuf-lite'),
             project(':grpc-stub'),
             project(':grpc-testing'),
-            libraries.hdrhistogram,
             libraries.junit,
             libraries.truth,
             libraries.androidx.test.rules,

android-interop-testing/src/generated/debug/grpc/io/grpc/testing/integration/LoadBalancerStatsServiceGrpc.java

@@ -7,9 +7,6 @@ import static io.grpc.MethodDescriptor.generateFullMethodName;
  * A service used to obtain stats for verifying LB behavior.
  * </pre>
  */
-@javax.annotation.Generated(
-    value = "by gRPC proto compiler",
-    comments = "Source: grpc/testing/test.proto")
 @io.grpc.stub.annotations.GrpcGenerated
 public final class LoadBalancerStatsServiceGrpc {
 
@@ -92,6 +89,21 @@ public final class LoadBalancerStatsServiceGrpc {
     return LoadBalancerStatsServiceStub.newStub(factory, channel);
   }
 
+  /**
+   * Creates a new blocking-style stub that supports all types of calls on the service
+   */
+  public static LoadBalancerStatsServiceBlockingV2Stub newBlockingV2Stub(
+      io.grpc.Channel channel) {
+    io.grpc.stub.AbstractStub.StubFactory<LoadBalancerStatsServiceBlockingV2Stub> factory =
+      new io.grpc.stub.AbstractStub.StubFactory<LoadBalancerStatsServiceBlockingV2Stub>() {
+        @java.lang.Override
+        public LoadBalancerStatsServiceBlockingV2Stub newStub(io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+          return new LoadBalancerStatsServiceBlockingV2Stub(channel, callOptions);
+        }
+      };
+    return LoadBalancerStatsServiceBlockingV2Stub.newStub(factory, channel);
+  }
+
   /**
    * Creates a new blocking-style stub that supports unary and streaming output calls on the service
    */
@@ -212,6 +224,46 @@ public final class LoadBalancerStatsServiceGrpc {
    * A service used to obtain stats for verifying LB behavior.
    * </pre>
    */
+  public static final class LoadBalancerStatsServiceBlockingV2Stub
+      extends io.grpc.stub.AbstractBlockingStub<LoadBalancerStatsServiceBlockingV2Stub> {
+    private LoadBalancerStatsServiceBlockingV2Stub(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      super(channel, callOptions);
+    }
+
+    @java.lang.Override
+    protected LoadBalancerStatsServiceBlockingV2Stub build(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      return new LoadBalancerStatsServiceBlockingV2Stub(channel, callOptions);
+    }
+
+    /**
+     * <pre>
+     * Gets the backend distribution for RPCs sent by a test client.
+     * </pre>
+     */
+    public io.grpc.testing.integration.Messages.LoadBalancerStatsResponse getClientStats(io.grpc.testing.integration.Messages.LoadBalancerStatsRequest request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getGetClientStatsMethod(), getCallOptions(), request);
+    }
+
+    /**
+     * <pre>
+     * Gets the accumulated stats for RPCs sent by a test client.
+     * </pre>
+     */
+    public io.grpc.testing.integration.Messages.LoadBalancerAccumulatedStatsResponse getClientAccumulatedStats(io.grpc.testing.integration.Messages.LoadBalancerAccumulatedStatsRequest request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getGetClientAccumulatedStatsMethod(), getCallOptions(), request);
+    }
+  }
+
+  /**
+   * A stub to allow clients to do limited synchronous rpc calls to service LoadBalancerStatsService.
+   * <pre>
+   * A service used to obtain stats for verifying LB behavior.
+   * </pre>
+   */
   public static final class LoadBalancerStatsServiceBlockingStub
       extends io.grpc.stub.AbstractBlockingStub<LoadBalancerStatsServiceBlockingStub> {
     private LoadBalancerStatsServiceBlockingStub(

android-interop-testing/src/generated/debug/grpc/io/grpc/testing/integration/MetricsServiceGrpc.java

@@ -4,9 +4,6 @@ import static io.grpc.MethodDescriptor.generateFullMethodName;
 
 /**
  */
-@javax.annotation.Generated(
-    value = "by gRPC proto compiler",
-    comments = "Source: grpc/testing/metrics.proto")
 @io.grpc.stub.annotations.GrpcGenerated
 public final class MetricsServiceGrpc {
 
@@ -89,6 +86,21 @@ public final class MetricsServiceGrpc {
     return MetricsServiceStub.newStub(factory, channel);
   }
 
+  /**
+   * Creates a new blocking-style stub that supports all types of calls on the service
+   */
+  public static MetricsServiceBlockingV2Stub newBlockingV2Stub(
+      io.grpc.Channel channel) {
+    io.grpc.stub.AbstractStub.StubFactory<MetricsServiceBlockingV2Stub> factory =
+      new io.grpc.stub.AbstractStub.StubFactory<MetricsServiceBlockingV2Stub>() {
+        @java.lang.Override
+        public MetricsServiceBlockingV2Stub newStub(io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+          return new MetricsServiceBlockingV2Stub(channel, callOptions);
+        }
+      };
+    return MetricsServiceBlockingV2Stub.newStub(factory, channel);
+  }
+
   /**
    * Creates a new blocking-style stub that supports unary and streaming output calls on the service
    */
@@ -199,6 +211,46 @@ public final class MetricsServiceGrpc {
   /**
    * A stub to allow clients to do synchronous rpc calls to service MetricsService.
    */
+  public static final class MetricsServiceBlockingV2Stub
+      extends io.grpc.stub.AbstractBlockingStub<MetricsServiceBlockingV2Stub> {
+    private MetricsServiceBlockingV2Stub(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      super(channel, callOptions);
+    }
+
+    @java.lang.Override
+    protected MetricsServiceBlockingV2Stub build(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      return new MetricsServiceBlockingV2Stub(channel, callOptions);
+    }
+
+    /**
+     * <pre>
+     * Returns the values of all the gauges that are currently being maintained by
+     * the service
+     * </pre>
+     */
+    @io.grpc.ExperimentalApi("https://github.com/grpc/grpc-java/issues/10918")
+    public io.grpc.stub.BlockingClientCall<?, io.grpc.testing.integration.Metrics.GaugeResponse>
+        getAllGauges(io.grpc.testing.integration.Metrics.EmptyMessage request) {
+      return io.grpc.stub.ClientCalls.blockingV2ServerStreamingCall(
+          getChannel(), getGetAllGaugesMethod(), getCallOptions(), request);
+    }
+
+    /**
+     * <pre>
+     * Returns the value of one gauge
+     * </pre>
+     */
+    public io.grpc.testing.integration.Metrics.GaugeResponse getGauge(io.grpc.testing.integration.Metrics.GaugeRequest request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getGetGaugeMethod(), getCallOptions(), request);
+    }
+  }
+
+  /**
+   * A stub to allow clients to do limited synchronous rpc calls to service MetricsService.
+   */
   public static final class MetricsServiceBlockingStub
       extends io.grpc.stub.AbstractBlockingStub<MetricsServiceBlockingStub> {
     private MetricsServiceBlockingStub(

android-interop-testing/src/generated/debug/grpc/io/grpc/testing/integration/ReconnectServiceGrpc.java

@@ -7,9 +7,6 @@ import static io.grpc.MethodDescriptor.generateFullMethodName;
  * A service used to control reconnect server.
  * </pre>
  */
-@javax.annotation.Generated(
-    value = "by gRPC proto compiler",
-    comments = "Source: grpc/testing/test.proto")
 @io.grpc.stub.annotations.GrpcGenerated
 public final class ReconnectServiceGrpc {
 
@@ -92,6 +89,21 @@ public final class ReconnectServiceGrpc {
     return ReconnectServiceStub.newStub(factory, channel);
   }
 
+  /**
+   * Creates a new blocking-style stub that supports all types of calls on the service
+   */
+  public static ReconnectServiceBlockingV2Stub newBlockingV2Stub(
+      io.grpc.Channel channel) {
+    io.grpc.stub.AbstractStub.StubFactory<ReconnectServiceBlockingV2Stub> factory =
+      new io.grpc.stub.AbstractStub.StubFactory<ReconnectServiceBlockingV2Stub>() {
+        @java.lang.Override
+        public ReconnectServiceBlockingV2Stub newStub(io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+          return new ReconnectServiceBlockingV2Stub(channel, callOptions);
+        }
+      };
+    return ReconnectServiceBlockingV2Stub.newStub(factory, channel);
+  }
+
   /**
    * Creates a new blocking-style stub that supports unary and streaming output calls on the service
    */
@@ -200,6 +212,40 @@ public final class ReconnectServiceGrpc {
    * A service used to control reconnect server.
    * </pre>
    */
+  public static final class ReconnectServiceBlockingV2Stub
+      extends io.grpc.stub.AbstractBlockingStub<ReconnectServiceBlockingV2Stub> {
+    private ReconnectServiceBlockingV2Stub(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      super(channel, callOptions);
+    }
+
+    @java.lang.Override
+    protected ReconnectServiceBlockingV2Stub build(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      return new ReconnectServiceBlockingV2Stub(channel, callOptions);
+    }
+
+    /**
+     */
+    public io.grpc.testing.integration.EmptyProtos.Empty start(io.grpc.testing.integration.Messages.ReconnectParams request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getStartMethod(), getCallOptions(), request);
+    }
+
+    /**
+     */
+    public io.grpc.testing.integration.Messages.ReconnectInfo stop(io.grpc.testing.integration.EmptyProtos.Empty request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getStopMethod(), getCallOptions(), request);
+    }
+  }
+
+  /**
+   * A stub to allow clients to do limited synchronous rpc calls to service ReconnectService.
+   * <pre>
+   * A service used to control reconnect server.
+   * </pre>
+   */
   public static final class ReconnectServiceBlockingStub
       extends io.grpc.stub.AbstractBlockingStub<ReconnectServiceBlockingStub> {
     private ReconnectServiceBlockingStub(

android-interop-testing/src/generated/debug/grpc/io/grpc/testing/integration/TestServiceGrpc.java

@@ -8,9 +8,6 @@ import static io.grpc.MethodDescriptor.generateFullMethodName;
  * performance with various types of payload.
  * </pre>
  */
-@javax.annotation.Generated(
-    value = "by gRPC proto compiler",
-    comments = "Source: grpc/testing/test.proto")
 @io.grpc.stub.annotations.GrpcGenerated
 public final class TestServiceGrpc {
 
@@ -273,6 +270,21 @@ public final class TestServiceGrpc {
     return TestServiceStub.newStub(factory, channel);
   }
 
+  /**
+   * Creates a new blocking-style stub that supports all types of calls on the service
+   */
+  public static TestServiceBlockingV2Stub newBlockingV2Stub(
+      io.grpc.Channel channel) {
+    io.grpc.stub.AbstractStub.StubFactory<TestServiceBlockingV2Stub> factory =
+      new io.grpc.stub.AbstractStub.StubFactory<TestServiceBlockingV2Stub>() {
+        @java.lang.Override
+        public TestServiceBlockingV2Stub newStub(io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+          return new TestServiceBlockingV2Stub(channel, callOptions);
+        }
+      };
+    return TestServiceBlockingV2Stub.newStub(factory, channel);
+  }
+
   /**
    * Creates a new blocking-style stub that supports unary and streaming output calls on the service
    */
@@ -543,6 +555,125 @@ public final class TestServiceGrpc {
    * performance with various types of payload.
    * </pre>
    */
+  public static final class TestServiceBlockingV2Stub
+      extends io.grpc.stub.AbstractBlockingStub<TestServiceBlockingV2Stub> {
+    private TestServiceBlockingV2Stub(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      super(channel, callOptions);
+    }
+
+    @java.lang.Override
+    protected TestServiceBlockingV2Stub build(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      return new TestServiceBlockingV2Stub(channel, callOptions);
+    }
+
+    /**
+     * <pre>
+     * One empty request followed by one empty response.
+     * </pre>
+     */
+    public io.grpc.testing.integration.EmptyProtos.Empty emptyCall(io.grpc.testing.integration.EmptyProtos.Empty request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getEmptyCallMethod(), getCallOptions(), request);
+    }
+
+    /**
+     * <pre>
+     * One request followed by one response.
+     * </pre>
+     */
+    public io.grpc.testing.integration.Messages.SimpleResponse unaryCall(io.grpc.testing.integration.Messages.SimpleRequest request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getUnaryCallMethod(), getCallOptions(), request);
+    }
+
+    /**
+     * <pre>
+     * One request followed by one response. Response has cache control
+     * headers set such that a caching HTTP proxy (such as GFE) can
+     * satisfy subsequent requests.
+     * </pre>
+     */
+    public io.grpc.testing.integration.Messages.SimpleResponse cacheableUnaryCall(io.grpc.testing.integration.Messages.SimpleRequest request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getCacheableUnaryCallMethod(), getCallOptions(), request);
+    }
+
+    /**
+     * <pre>
+     * One request followed by a sequence of responses (streamed download).
+     * The server returns the payload with client desired type and sizes.
+     * </pre>
+     */
+    @io.grpc.ExperimentalApi("https://github.com/grpc/grpc-java/issues/10918")
+    public io.grpc.stub.BlockingClientCall<?, io.grpc.testing.integration.Messages.StreamingOutputCallResponse>
+        streamingOutputCall(io.grpc.testing.integration.Messages.StreamingOutputCallRequest request) {
+      return io.grpc.stub.ClientCalls.blockingV2ServerStreamingCall(
+          getChannel(), getStreamingOutputCallMethod(), getCallOptions(), request);
+    }
+
+    /**
+     * <pre>
+     * A sequence of requests followed by one response (streamed upload).
+     * The server returns the aggregated size of client payload as the result.
+     * </pre>
+     */
+    @io.grpc.ExperimentalApi("https://github.com/grpc/grpc-java/issues/10918")
+    public io.grpc.stub.BlockingClientCall<io.grpc.testing.integration.Messages.StreamingInputCallRequest, io.grpc.testing.integration.Messages.StreamingInputCallResponse>
+        streamingInputCall() {
+      return io.grpc.stub.ClientCalls.blockingClientStreamingCall(
+          getChannel(), getStreamingInputCallMethod(), getCallOptions());
+    }
+
+    /**
+     * <pre>
+     * A sequence of requests with each request served by the server immediately.
+     * As one request could lead to multiple responses, this interface
+     * demonstrates the idea of full duplexing.
+     * </pre>
+     */
+    @io.grpc.ExperimentalApi("https://github.com/grpc/grpc-java/issues/10918")
+    public io.grpc.stub.BlockingClientCall<io.grpc.testing.integration.Messages.StreamingOutputCallRequest, io.grpc.testing.integration.Messages.StreamingOutputCallResponse>
+        fullDuplexCall() {
+      return io.grpc.stub.ClientCalls.blockingBidiStreamingCall(
+          getChannel(), getFullDuplexCallMethod(), getCallOptions());
+    }
+
+    /**
+     * <pre>
+     * A sequence of requests followed by a sequence of responses.
+     * The server buffers all the client requests and then serves them in order. A
+     * stream of responses are returned to the client when the server starts with
+     * first request.
+     * </pre>
+     */
+    @io.grpc.ExperimentalApi("https://github.com/grpc/grpc-java/issues/10918")
+    public io.grpc.stub.BlockingClientCall<io.grpc.testing.integration.Messages.StreamingOutputCallRequest, io.grpc.testing.integration.Messages.StreamingOutputCallResponse>
+        halfDuplexCall() {
+      return io.grpc.stub.ClientCalls.blockingBidiStreamingCall(
+          getChannel(), getHalfDuplexCallMethod(), getCallOptions());
+    }
+
+    /**
+     * <pre>
+     * The test server will not implement this method. It will be used
+     * to test the behavior when clients call unimplemented methods.
+     * </pre>
+     */
+    public io.grpc.testing.integration.EmptyProtos.Empty unimplementedCall(io.grpc.testing.integration.EmptyProtos.Empty request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getUnimplementedCallMethod(), getCallOptions(), request);
+    }
+  }
+
+  /**
+   * A stub to allow clients to do limited synchronous rpc calls to service TestService.
+   * <pre>
+   * A simple service to test the various types of RPCs and experiment with
+   * performance with various types of payload.
+   * </pre>
+   */
   public static final class TestServiceBlockingStub
       extends io.grpc.stub.AbstractBlockingStub<TestServiceBlockingStub> {
     private TestServiceBlockingStub(

android-interop-testing/src/generated/debug/grpc/io/grpc/testing/integration/UnimplementedServiceGrpc.java

@@ -8,9 +8,6 @@ import static io.grpc.MethodDescriptor.generateFullMethodName;
  * that case.
  * </pre>
  */
-@javax.annotation.Generated(
-    value = "by gRPC proto compiler",
-    comments = "Source: grpc/testing/test.proto")
 @io.grpc.stub.annotations.GrpcGenerated
 public final class UnimplementedServiceGrpc {
 
@@ -63,6 +60,21 @@ public final class UnimplementedServiceGrpc {
     return UnimplementedServiceStub.newStub(factory, channel);
   }
 
+  /**
+   * Creates a new blocking-style stub that supports all types of calls on the service
+   */
+  public static UnimplementedServiceBlockingV2Stub newBlockingV2Stub(
+      io.grpc.Channel channel) {
+    io.grpc.stub.AbstractStub.StubFactory<UnimplementedServiceBlockingV2Stub> factory =
+      new io.grpc.stub.AbstractStub.StubFactory<UnimplementedServiceBlockingV2Stub>() {
+        @java.lang.Override
+        public UnimplementedServiceBlockingV2Stub newStub(io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+          return new UnimplementedServiceBlockingV2Stub(channel, callOptions);
+        }
+      };
+    return UnimplementedServiceBlockingV2Stub.newStub(factory, channel);
+  }
+
   /**
    * Creates a new blocking-style stub that supports unary and streaming output calls on the service
    */
@@ -166,6 +178,37 @@ public final class UnimplementedServiceGrpc {
    * that case.
    * </pre>
    */
+  public static final class UnimplementedServiceBlockingV2Stub
+      extends io.grpc.stub.AbstractBlockingStub<UnimplementedServiceBlockingV2Stub> {
+    private UnimplementedServiceBlockingV2Stub(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      super(channel, callOptions);
+    }
+
+    @java.lang.Override
+    protected UnimplementedServiceBlockingV2Stub build(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      return new UnimplementedServiceBlockingV2Stub(channel, callOptions);
+    }
+
+    /**
+     * <pre>
+     * A call that no server should implement
+     * </pre>
+     */
+    public io.grpc.testing.integration.EmptyProtos.Empty unimplementedCall(io.grpc.testing.integration.EmptyProtos.Empty request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getUnimplementedCallMethod(), getCallOptions(), request);
+    }
+  }
+
+  /**
+   * A stub to allow clients to do limited synchronous rpc calls to service UnimplementedService.
+   * <pre>
+   * A simple service NOT implemented at servers so clients can test for
+   * that case.
+   * </pre>
+   */
   public static final class UnimplementedServiceBlockingStub
       extends io.grpc.stub.AbstractBlockingStub<UnimplementedServiceBlockingStub> {
     private UnimplementedServiceBlockingStub(

android-interop-testing/src/generated/debug/grpc/io/grpc/testing/integration/XdsUpdateClientConfigureServiceGrpc.java

@@ -7,9 +7,6 @@ import static io.grpc.MethodDescriptor.generateFullMethodName;
  * A service to dynamically update the configuration of an xDS test client.
  * </pre>
  */
-@javax.annotation.Generated(
-    value = "by gRPC proto compiler",
-    comments = "Source: grpc/testing/test.proto")
 @io.grpc.stub.annotations.GrpcGenerated
 public final class XdsUpdateClientConfigureServiceGrpc {
 
@@ -62,6 +59,21 @@ public final class XdsUpdateClientConfigureServiceGrpc {
     return XdsUpdateClientConfigureServiceStub.newStub(factory, channel);
   }
 
+  /**
+   * Creates a new blocking-style stub that supports all types of calls on the service
+   */
+  public static XdsUpdateClientConfigureServiceBlockingV2Stub newBlockingV2Stub(
+      io.grpc.Channel channel) {
+    io.grpc.stub.AbstractStub.StubFactory<XdsUpdateClientConfigureServiceBlockingV2Stub> factory =
+      new io.grpc.stub.AbstractStub.StubFactory<XdsUpdateClientConfigureServiceBlockingV2Stub>() {
+        @java.lang.Override
+        public XdsUpdateClientConfigureServiceBlockingV2Stub newStub(io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+          return new XdsUpdateClientConfigureServiceBlockingV2Stub(channel, callOptions);
+        }
+      };
+    return XdsUpdateClientConfigureServiceBlockingV2Stub.newStub(factory, channel);
+  }
+
   /**
    * Creates a new blocking-style stub that supports unary and streaming output calls on the service
    */
@@ -161,6 +173,36 @@ public final class XdsUpdateClientConfigureServiceGrpc {
    * A service to dynamically update the configuration of an xDS test client.
    * </pre>
    */
+  public static final class XdsUpdateClientConfigureServiceBlockingV2Stub
+      extends io.grpc.stub.AbstractBlockingStub<XdsUpdateClientConfigureServiceBlockingV2Stub> {
+    private XdsUpdateClientConfigureServiceBlockingV2Stub(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      super(channel, callOptions);
+    }
+
+    @java.lang.Override
+    protected XdsUpdateClientConfigureServiceBlockingV2Stub build(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      return new XdsUpdateClientConfigureServiceBlockingV2Stub(channel, callOptions);
+    }
+
+    /**
+     * <pre>
+     * Update the tes client's configuration.
+     * </pre>
+     */
+    public io.grpc.testing.integration.Messages.ClientConfigureResponse configure(io.grpc.testing.integration.Messages.ClientConfigureRequest request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getConfigureMethod(), getCallOptions(), request);
+    }
+  }
+
+  /**
+   * A stub to allow clients to do limited synchronous rpc calls to service XdsUpdateClientConfigureService.
+   * <pre>
+   * A service to dynamically update the configuration of an xDS test client.
+   * </pre>
+   */
   public static final class XdsUpdateClientConfigureServiceBlockingStub
       extends io.grpc.stub.AbstractBlockingStub<XdsUpdateClientConfigureServiceBlockingStub> {
     private XdsUpdateClientConfigureServiceBlockingStub(

android-interop-testing/src/generated/debug/grpc/io/grpc/testing/integration/XdsUpdateHealthServiceGrpc.java

@@ -7,9 +7,6 @@ import static io.grpc.MethodDescriptor.generateFullMethodName;
  * A service to remotely control health status of an xDS test server.
  * </pre>
  */
-@javax.annotation.Generated(
-    value = "by gRPC proto compiler",
-    comments = "Source: grpc/testing/test.proto")
 @io.grpc.stub.annotations.GrpcGenerated
 public final class XdsUpdateHealthServiceGrpc {
 
@@ -92,6 +89,21 @@ public final class XdsUpdateHealthServiceGrpc {
     return XdsUpdateHealthServiceStub.newStub(factory, channel);
   }
 
+  /**
+   * Creates a new blocking-style stub that supports all types of calls on the service
+   */
+  public static XdsUpdateHealthServiceBlockingV2Stub newBlockingV2Stub(
+      io.grpc.Channel channel) {
+    io.grpc.stub.AbstractStub.StubFactory<XdsUpdateHealthServiceBlockingV2Stub> factory =
+      new io.grpc.stub.AbstractStub.StubFactory<XdsUpdateHealthServiceBlockingV2Stub>() {
+        @java.lang.Override
+        public XdsUpdateHealthServiceBlockingV2Stub newStub(io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+          return new XdsUpdateHealthServiceBlockingV2Stub(channel, callOptions);
+        }
+      };
+    return XdsUpdateHealthServiceBlockingV2Stub.newStub(factory, channel);
+  }
+
   /**
    * Creates a new blocking-style stub that supports unary and streaming output calls on the service
    */
@@ -200,6 +212,40 @@ public final class XdsUpdateHealthServiceGrpc {
    * A service to remotely control health status of an xDS test server.
    * </pre>
    */
+  public static final class XdsUpdateHealthServiceBlockingV2Stub
+      extends io.grpc.stub.AbstractBlockingStub<XdsUpdateHealthServiceBlockingV2Stub> {
+    private XdsUpdateHealthServiceBlockingV2Stub(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      super(channel, callOptions);
+    }
+
+    @java.lang.Override
+    protected XdsUpdateHealthServiceBlockingV2Stub build(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      return new XdsUpdateHealthServiceBlockingV2Stub(channel, callOptions);
+    }
+
+    /**
+     */
+    public io.grpc.testing.integration.EmptyProtos.Empty setServing(io.grpc.testing.integration.EmptyProtos.Empty request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getSetServingMethod(), getCallOptions(), request);
+    }
+
+    /**
+     */
+    public io.grpc.testing.integration.EmptyProtos.Empty setNotServing(io.grpc.testing.integration.EmptyProtos.Empty request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getSetNotServingMethod(), getCallOptions(), request);
+    }
+  }
+
+  /**
+   * A stub to allow clients to do limited synchronous rpc calls to service XdsUpdateHealthService.
+   * <pre>
+   * A service to remotely control health status of an xDS test server.
+   * </pre>
+   */
   public static final class XdsUpdateHealthServiceBlockingStub
       extends io.grpc.stub.AbstractBlockingStub<XdsUpdateHealthServiceBlockingStub> {
     private XdsUpdateHealthServiceBlockingStub(

android-interop-testing/src/generated/release/grpc/io/grpc/testing/integration/LoadBalancerStatsServiceGrpc.java

@@ -7,9 +7,6 @@ import static io.grpc.MethodDescriptor.generateFullMethodName;
  * A service used to obtain stats for verifying LB behavior.
  * </pre>
  */
-@javax.annotation.Generated(
-    value = "by gRPC proto compiler",
-    comments = "Source: grpc/testing/test.proto")
 @io.grpc.stub.annotations.GrpcGenerated
 public final class LoadBalancerStatsServiceGrpc {
 
@@ -92,6 +89,21 @@ public final class LoadBalancerStatsServiceGrpc {
     return LoadBalancerStatsServiceStub.newStub(factory, channel);
   }
 
+  /**
+   * Creates a new blocking-style stub that supports all types of calls on the service
+   */
+  public static LoadBalancerStatsServiceBlockingV2Stub newBlockingV2Stub(
+      io.grpc.Channel channel) {
+    io.grpc.stub.AbstractStub.StubFactory<LoadBalancerStatsServiceBlockingV2Stub> factory =
+      new io.grpc.stub.AbstractStub.StubFactory<LoadBalancerStatsServiceBlockingV2Stub>() {
+        @java.lang.Override
+        public LoadBalancerStatsServiceBlockingV2Stub newStub(io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+          return new LoadBalancerStatsServiceBlockingV2Stub(channel, callOptions);
+        }
+      };
+    return LoadBalancerStatsServiceBlockingV2Stub.newStub(factory, channel);
+  }
+
   /**
    * Creates a new blocking-style stub that supports unary and streaming output calls on the service
    */
@@ -212,6 +224,46 @@ public final class LoadBalancerStatsServiceGrpc {
    * A service used to obtain stats for verifying LB behavior.
    * </pre>
    */
+  public static final class LoadBalancerStatsServiceBlockingV2Stub
+      extends io.grpc.stub.AbstractBlockingStub<LoadBalancerStatsServiceBlockingV2Stub> {
+    private LoadBalancerStatsServiceBlockingV2Stub(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      super(channel, callOptions);
+    }
+
+    @java.lang.Override
+    protected LoadBalancerStatsServiceBlockingV2Stub build(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      return new LoadBalancerStatsServiceBlockingV2Stub(channel, callOptions);
+    }
+
+    /**
+     * <pre>
+     * Gets the backend distribution for RPCs sent by a test client.
+     * </pre>
+     */
+    public io.grpc.testing.integration.Messages.LoadBalancerStatsResponse getClientStats(io.grpc.testing.integration.Messages.LoadBalancerStatsRequest request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getGetClientStatsMethod(), getCallOptions(), request);
+    }
+
+    /**
+     * <pre>
+     * Gets the accumulated stats for RPCs sent by a test client.
+     * </pre>
+     */
+    public io.grpc.testing.integration.Messages.LoadBalancerAccumulatedStatsResponse getClientAccumulatedStats(io.grpc.testing.integration.Messages.LoadBalancerAccumulatedStatsRequest request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getGetClientAccumulatedStatsMethod(), getCallOptions(), request);
+    }
+  }
+
+  /**
+   * A stub to allow clients to do limited synchronous rpc calls to service LoadBalancerStatsService.
+   * <pre>
+   * A service used to obtain stats for verifying LB behavior.
+   * </pre>
+   */
   public static final class LoadBalancerStatsServiceBlockingStub
       extends io.grpc.stub.AbstractBlockingStub<LoadBalancerStatsServiceBlockingStub> {
     private LoadBalancerStatsServiceBlockingStub(

android-interop-testing/src/generated/release/grpc/io/grpc/testing/integration/MetricsServiceGrpc.java

@@ -4,9 +4,6 @@ import static io.grpc.MethodDescriptor.generateFullMethodName;
 
 /**
  */
-@javax.annotation.Generated(
-    value = "by gRPC proto compiler",
-    comments = "Source: grpc/testing/metrics.proto")
 @io.grpc.stub.annotations.GrpcGenerated
 public final class MetricsServiceGrpc {
 
@@ -89,6 +86,21 @@ public final class MetricsServiceGrpc {
     return MetricsServiceStub.newStub(factory, channel);
   }
 
+  /**
+   * Creates a new blocking-style stub that supports all types of calls on the service
+   */
+  public static MetricsServiceBlockingV2Stub newBlockingV2Stub(
+      io.grpc.Channel channel) {
+    io.grpc.stub.AbstractStub.StubFactory<MetricsServiceBlockingV2Stub> factory =
+      new io.grpc.stub.AbstractStub.StubFactory<MetricsServiceBlockingV2Stub>() {
+        @java.lang.Override
+        public MetricsServiceBlockingV2Stub newStub(io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+          return new MetricsServiceBlockingV2Stub(channel, callOptions);
+        }
+      };
+    return MetricsServiceBlockingV2Stub.newStub(factory, channel);
+  }
+
   /**
    * Creates a new blocking-style stub that supports unary and streaming output calls on the service
    */
@@ -199,6 +211,46 @@ public final class MetricsServiceGrpc {
   /**
    * A stub to allow clients to do synchronous rpc calls to service MetricsService.
    */
+  public static final class MetricsServiceBlockingV2Stub
+      extends io.grpc.stub.AbstractBlockingStub<MetricsServiceBlockingV2Stub> {
+    private MetricsServiceBlockingV2Stub(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      super(channel, callOptions);
+    }
+
+    @java.lang.Override
+    protected MetricsServiceBlockingV2Stub build(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      return new MetricsServiceBlockingV2Stub(channel, callOptions);
+    }
+
+    /**
+     * <pre>
+     * Returns the values of all the gauges that are currently being maintained by
+     * the service
+     * </pre>
+     */
+    @io.grpc.ExperimentalApi("https://github.com/grpc/grpc-java/issues/10918")
+    public io.grpc.stub.BlockingClientCall<?, io.grpc.testing.integration.Metrics.GaugeResponse>
+        getAllGauges(io.grpc.testing.integration.Metrics.EmptyMessage request) {
+      return io.grpc.stub.ClientCalls.blockingV2ServerStreamingCall(
+          getChannel(), getGetAllGaugesMethod(), getCallOptions(), request);
+    }
+
+    /**
+     * <pre>
+     * Returns the value of one gauge
+     * </pre>
+     */
+    public io.grpc.testing.integration.Metrics.GaugeResponse getGauge(io.grpc.testing.integration.Metrics.GaugeRequest request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getGetGaugeMethod(), getCallOptions(), request);
+    }
+  }
+
+  /**
+   * A stub to allow clients to do limited synchronous rpc calls to service MetricsService.
+   */
   public static final class MetricsServiceBlockingStub
       extends io.grpc.stub.AbstractBlockingStub<MetricsServiceBlockingStub> {
     private MetricsServiceBlockingStub(

android-interop-testing/src/generated/release/grpc/io/grpc/testing/integration/ReconnectServiceGrpc.java

@@ -7,9 +7,6 @@ import static io.grpc.MethodDescriptor.generateFullMethodName;
  * A service used to control reconnect server.
  * </pre>
  */
-@javax.annotation.Generated(
-    value = "by gRPC proto compiler",
-    comments = "Source: grpc/testing/test.proto")
 @io.grpc.stub.annotations.GrpcGenerated
 public final class ReconnectServiceGrpc {
 
@@ -92,6 +89,21 @@ public final class ReconnectServiceGrpc {
     return ReconnectServiceStub.newStub(factory, channel);
   }
 
+  /**
+   * Creates a new blocking-style stub that supports all types of calls on the service
+   */
+  public static ReconnectServiceBlockingV2Stub newBlockingV2Stub(
+      io.grpc.Channel channel) {
+    io.grpc.stub.AbstractStub.StubFactory<ReconnectServiceBlockingV2Stub> factory =
+      new io.grpc.stub.AbstractStub.StubFactory<ReconnectServiceBlockingV2Stub>() {
+        @java.lang.Override
+        public ReconnectServiceBlockingV2Stub newStub(io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+          return new ReconnectServiceBlockingV2Stub(channel, callOptions);
+        }
+      };
+    return ReconnectServiceBlockingV2Stub.newStub(factory, channel);
+  }
+
   /**
    * Creates a new blocking-style stub that supports unary and streaming output calls on the service
    */
@@ -200,6 +212,40 @@ public final class ReconnectServiceGrpc {
    * A service used to control reconnect server.
    * </pre>
    */
+  public static final class ReconnectServiceBlockingV2Stub
+      extends io.grpc.stub.AbstractBlockingStub<ReconnectServiceBlockingV2Stub> {
+    private ReconnectServiceBlockingV2Stub(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      super(channel, callOptions);
+    }
+
+    @java.lang.Override
+    protected ReconnectServiceBlockingV2Stub build(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      return new ReconnectServiceBlockingV2Stub(channel, callOptions);
+    }
+
+    /**
+     */
+    public io.grpc.testing.integration.EmptyProtos.Empty start(io.grpc.testing.integration.Messages.ReconnectParams request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getStartMethod(), getCallOptions(), request);
+    }
+
+    /**
+     */
+    public io.grpc.testing.integration.Messages.ReconnectInfo stop(io.grpc.testing.integration.EmptyProtos.Empty request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getStopMethod(), getCallOptions(), request);
+    }
+  }
+
+  /**
+   * A stub to allow clients to do limited synchronous rpc calls to service ReconnectService.
+   * <pre>
+   * A service used to control reconnect server.
+   * </pre>
+   */
   public static final class ReconnectServiceBlockingStub
       extends io.grpc.stub.AbstractBlockingStub<ReconnectServiceBlockingStub> {
     private ReconnectServiceBlockingStub(

android-interop-testing/src/generated/release/grpc/io/grpc/testing/integration/TestServiceGrpc.java

@@ -8,9 +8,6 @@ import static io.grpc.MethodDescriptor.generateFullMethodName;
  * performance with various types of payload.
  * </pre>
  */
-@javax.annotation.Generated(
-    value = "by gRPC proto compiler",
-    comments = "Source: grpc/testing/test.proto")
 @io.grpc.stub.annotations.GrpcGenerated
 public final class TestServiceGrpc {
 
@@ -273,6 +270,21 @@ public final class TestServiceGrpc {
     return TestServiceStub.newStub(factory, channel);
   }
 
+  /**
+   * Creates a new blocking-style stub that supports all types of calls on the service
+   */
+  public static TestServiceBlockingV2Stub newBlockingV2Stub(
+      io.grpc.Channel channel) {
+    io.grpc.stub.AbstractStub.StubFactory<TestServiceBlockingV2Stub> factory =
+      new io.grpc.stub.AbstractStub.StubFactory<TestServiceBlockingV2Stub>() {
+        @java.lang.Override
+        public TestServiceBlockingV2Stub newStub(io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+          return new TestServiceBlockingV2Stub(channel, callOptions);
+        }
+      };
+    return TestServiceBlockingV2Stub.newStub(factory, channel);
+  }
+
   /**
    * Creates a new blocking-style stub that supports unary and streaming output calls on the service
    */
@@ -543,6 +555,125 @@ public final class TestServiceGrpc {
    * performance with various types of payload.
    * </pre>
    */
+  public static final class TestServiceBlockingV2Stub
+      extends io.grpc.stub.AbstractBlockingStub<TestServiceBlockingV2Stub> {
+    private TestServiceBlockingV2Stub(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      super(channel, callOptions);
+    }
+
+    @java.lang.Override
+    protected TestServiceBlockingV2Stub build(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      return new TestServiceBlockingV2Stub(channel, callOptions);
+    }
+
+    /**
+     * <pre>
+     * One empty request followed by one empty response.
+     * </pre>
+     */
+    public io.grpc.testing.integration.EmptyProtos.Empty emptyCall(io.grpc.testing.integration.EmptyProtos.Empty request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getEmptyCallMethod(), getCallOptions(), request);
+    }
+
+    /**
+     * <pre>
+     * One request followed by one response.
+     * </pre>
+     */
+    public io.grpc.testing.integration.Messages.SimpleResponse unaryCall(io.grpc.testing.integration.Messages.SimpleRequest request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getUnaryCallMethod(), getCallOptions(), request);
+    }
+
+    /**
+     * <pre>
+     * One request followed by one response. Response has cache control
+     * headers set such that a caching HTTP proxy (such as GFE) can
+     * satisfy subsequent requests.
+     * </pre>
+     */
+    public io.grpc.testing.integration.Messages.SimpleResponse cacheableUnaryCall(io.grpc.testing.integration.Messages.SimpleRequest request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getCacheableUnaryCallMethod(), getCallOptions(), request);
+    }
+
+    /**
+     * <pre>
+     * One request followed by a sequence of responses (streamed download).
+     * The server returns the payload with client desired type and sizes.
+     * </pre>
+     */
+    @io.grpc.ExperimentalApi("https://github.com/grpc/grpc-java/issues/10918")
+    public io.grpc.stub.BlockingClientCall<?, io.grpc.testing.integration.Messages.StreamingOutputCallResponse>
+        streamingOutputCall(io.grpc.testing.integration.Messages.StreamingOutputCallRequest request) {
+      return io.grpc.stub.ClientCalls.blockingV2ServerStreamingCall(
+          getChannel(), getStreamingOutputCallMethod(), getCallOptions(), request);
+    }
+
+    /**
+     * <pre>
+     * A sequence of requests followed by one response (streamed upload).
+     * The server returns the aggregated size of client payload as the result.
+     * </pre>
+     */
+    @io.grpc.ExperimentalApi("https://github.com/grpc/grpc-java/issues/10918")
+    public io.grpc.stub.BlockingClientCall<io.grpc.testing.integration.Messages.StreamingInputCallRequest, io.grpc.testing.integration.Messages.StreamingInputCallResponse>
+        streamingInputCall() {
+      return io.grpc.stub.ClientCalls.blockingClientStreamingCall(
+          getChannel(), getStreamingInputCallMethod(), getCallOptions());
+    }
+
+    /**
+     * <pre>
+     * A sequence of requests with each request served by the server immediately.
+     * As one request could lead to multiple responses, this interface
+     * demonstrates the idea of full duplexing.
+     * </pre>
+     */
+    @io.grpc.ExperimentalApi("https://github.com/grpc/grpc-java/issues/10918")
+    public io.grpc.stub.BlockingClientCall<io.grpc.testing.integration.Messages.StreamingOutputCallRequest, io.grpc.testing.integration.Messages.StreamingOutputCallResponse>
+        fullDuplexCall() {
+      return io.grpc.stub.ClientCalls.blockingBidiStreamingCall(
+          getChannel(), getFullDuplexCallMethod(), getCallOptions());
+    }
+
+    /**
+     * <pre>
+     * A sequence of requests followed by a sequence of responses.
+     * The server buffers all the client requests and then serves them in order. A
+     * stream of responses are returned to the client when the server starts with
+     * first request.
+     * </pre>
+     */
+    @io.grpc.ExperimentalApi("https://github.com/grpc/grpc-java/issues/10918")
+    public io.grpc.stub.BlockingClientCall<io.grpc.testing.integration.Messages.StreamingOutputCallRequest, io.grpc.testing.integration.Messages.StreamingOutputCallResponse>
+        halfDuplexCall() {
+      return io.grpc.stub.ClientCalls.blockingBidiStreamingCall(
+          getChannel(), getHalfDuplexCallMethod(), getCallOptions());
+    }
+
+    /**
+     * <pre>
+     * The test server will not implement this method. It will be used
+     * to test the behavior when clients call unimplemented methods.
+     * </pre>
+     */
+    public io.grpc.testing.integration.EmptyProtos.Empty unimplementedCall(io.grpc.testing.integration.EmptyProtos.Empty request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getUnimplementedCallMethod(), getCallOptions(), request);
+    }
+  }
+
+  /**
+   * A stub to allow clients to do limited synchronous rpc calls to service TestService.
+   * <pre>
+   * A simple service to test the various types of RPCs and experiment with
+   * performance with various types of payload.
+   * </pre>
+   */
   public static final class TestServiceBlockingStub
       extends io.grpc.stub.AbstractBlockingStub<TestServiceBlockingStub> {
     private TestServiceBlockingStub(

android-interop-testing/src/generated/release/grpc/io/grpc/testing/integration/UnimplementedServiceGrpc.java

@@ -8,9 +8,6 @@ import static io.grpc.MethodDescriptor.generateFullMethodName;
  * that case.
  * </pre>
  */
-@javax.annotation.Generated(
-    value = "by gRPC proto compiler",
-    comments = "Source: grpc/testing/test.proto")
 @io.grpc.stub.annotations.GrpcGenerated
 public final class UnimplementedServiceGrpc {
 
@@ -63,6 +60,21 @@ public final class UnimplementedServiceGrpc {
     return UnimplementedServiceStub.newStub(factory, channel);
   }
 
+  /**
+   * Creates a new blocking-style stub that supports all types of calls on the service
+   */
+  public static UnimplementedServiceBlockingV2Stub newBlockingV2Stub(
+      io.grpc.Channel channel) {
+    io.grpc.stub.AbstractStub.StubFactory<UnimplementedServiceBlockingV2Stub> factory =
+      new io.grpc.stub.AbstractStub.StubFactory<UnimplementedServiceBlockingV2Stub>() {
+        @java.lang.Override
+        public UnimplementedServiceBlockingV2Stub newStub(io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+          return new UnimplementedServiceBlockingV2Stub(channel, callOptions);
+        }
+      };
+    return UnimplementedServiceBlockingV2Stub.newStub(factory, channel);
+  }
+
   /**
    * Creates a new blocking-style stub that supports unary and streaming output calls on the service
    */
@@ -166,6 +178,37 @@ public final class UnimplementedServiceGrpc {
    * that case.
    * </pre>
    */
+  public static final class UnimplementedServiceBlockingV2Stub
+      extends io.grpc.stub.AbstractBlockingStub<UnimplementedServiceBlockingV2Stub> {
+    private UnimplementedServiceBlockingV2Stub(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      super(channel, callOptions);
+    }
+
+    @java.lang.Override
+    protected UnimplementedServiceBlockingV2Stub build(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      return new UnimplementedServiceBlockingV2Stub(channel, callOptions);
+    }
+
+    /**
+     * <pre>
+     * A call that no server should implement
+     * </pre>
+     */
+    public io.grpc.testing.integration.EmptyProtos.Empty unimplementedCall(io.grpc.testing.integration.EmptyProtos.Empty request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getUnimplementedCallMethod(), getCallOptions(), request);
+    }
+  }
+
+  /**
+   * A stub to allow clients to do limited synchronous rpc calls to service UnimplementedService.
+   * <pre>
+   * A simple service NOT implemented at servers so clients can test for
+   * that case.
+   * </pre>
+   */
   public static final class UnimplementedServiceBlockingStub
       extends io.grpc.stub.AbstractBlockingStub<UnimplementedServiceBlockingStub> {
     private UnimplementedServiceBlockingStub(

android-interop-testing/src/generated/release/grpc/io/grpc/testing/integration/XdsUpdateClientConfigureServiceGrpc.java

@@ -7,9 +7,6 @@ import static io.grpc.MethodDescriptor.generateFullMethodName;
  * A service to dynamically update the configuration of an xDS test client.
  * </pre>
  */
-@javax.annotation.Generated(
-    value = "by gRPC proto compiler",
-    comments = "Source: grpc/testing/test.proto")
 @io.grpc.stub.annotations.GrpcGenerated
 public final class XdsUpdateClientConfigureServiceGrpc {
 
@@ -62,6 +59,21 @@ public final class XdsUpdateClientConfigureServiceGrpc {
     return XdsUpdateClientConfigureServiceStub.newStub(factory, channel);
   }
 
+  /**
+   * Creates a new blocking-style stub that supports all types of calls on the service
+   */
+  public static XdsUpdateClientConfigureServiceBlockingV2Stub newBlockingV2Stub(
+      io.grpc.Channel channel) {
+    io.grpc.stub.AbstractStub.StubFactory<XdsUpdateClientConfigureServiceBlockingV2Stub> factory =
+      new io.grpc.stub.AbstractStub.StubFactory<XdsUpdateClientConfigureServiceBlockingV2Stub>() {
+        @java.lang.Override
+        public XdsUpdateClientConfigureServiceBlockingV2Stub newStub(io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+          return new XdsUpdateClientConfigureServiceBlockingV2Stub(channel, callOptions);
+        }
+      };
+    return XdsUpdateClientConfigureServiceBlockingV2Stub.newStub(factory, channel);
+  }
+
   /**
    * Creates a new blocking-style stub that supports unary and streaming output calls on the service
    */
@@ -161,6 +173,36 @@ public final class XdsUpdateClientConfigureServiceGrpc {
    * A service to dynamically update the configuration of an xDS test client.
    * </pre>
    */
+  public static final class XdsUpdateClientConfigureServiceBlockingV2Stub
+      extends io.grpc.stub.AbstractBlockingStub<XdsUpdateClientConfigureServiceBlockingV2Stub> {
+    private XdsUpdateClientConfigureServiceBlockingV2Stub(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      super(channel, callOptions);
+    }
+
+    @java.lang.Override
+    protected XdsUpdateClientConfigureServiceBlockingV2Stub build(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      return new XdsUpdateClientConfigureServiceBlockingV2Stub(channel, callOptions);
+    }
+
+    /**
+     * <pre>
+     * Update the tes client's configuration.
+     * </pre>
+     */
+    public io.grpc.testing.integration.Messages.ClientConfigureResponse configure(io.grpc.testing.integration.Messages.ClientConfigureRequest request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getConfigureMethod(), getCallOptions(), request);
+    }
+  }
+
+  /**
+   * A stub to allow clients to do limited synchronous rpc calls to service XdsUpdateClientConfigureService.
+   * <pre>
+   * A service to dynamically update the configuration of an xDS test client.
+   * </pre>
+   */
   public static final class XdsUpdateClientConfigureServiceBlockingStub
       extends io.grpc.stub.AbstractBlockingStub<XdsUpdateClientConfigureServiceBlockingStub> {
     private XdsUpdateClientConfigureServiceBlockingStub(

android-interop-testing/src/generated/release/grpc/io/grpc/testing/integration/XdsUpdateHealthServiceGrpc.java

@@ -7,9 +7,6 @@ import static io.grpc.MethodDescriptor.generateFullMethodName;
  * A service to remotely control health status of an xDS test server.
  * </pre>
  */
-@javax.annotation.Generated(
-    value = "by gRPC proto compiler",
-    comments = "Source: grpc/testing/test.proto")
 @io.grpc.stub.annotations.GrpcGenerated
 public final class XdsUpdateHealthServiceGrpc {
 
@@ -92,6 +89,21 @@ public final class XdsUpdateHealthServiceGrpc {
     return XdsUpdateHealthServiceStub.newStub(factory, channel);
   }
 
+  /**
+   * Creates a new blocking-style stub that supports all types of calls on the service
+   */
+  public static XdsUpdateHealthServiceBlockingV2Stub newBlockingV2Stub(
+      io.grpc.Channel channel) {
+    io.grpc.stub.AbstractStub.StubFactory<XdsUpdateHealthServiceBlockingV2Stub> factory =
+      new io.grpc.stub.AbstractStub.StubFactory<XdsUpdateHealthServiceBlockingV2Stub>() {
+        @java.lang.Override
+        public XdsUpdateHealthServiceBlockingV2Stub newStub(io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+          return new XdsUpdateHealthServiceBlockingV2Stub(channel, callOptions);
+        }
+      };
+    return XdsUpdateHealthServiceBlockingV2Stub.newStub(factory, channel);
+  }
+
   /**
    * Creates a new blocking-style stub that supports unary and streaming output calls on the service
    */
@@ -200,6 +212,40 @@ public final class XdsUpdateHealthServiceGrpc {
    * A service to remotely control health status of an xDS test server.
    * </pre>
    */
+  public static final class XdsUpdateHealthServiceBlockingV2Stub
+      extends io.grpc.stub.AbstractBlockingStub<XdsUpdateHealthServiceBlockingV2Stub> {
+    private XdsUpdateHealthServiceBlockingV2Stub(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      super(channel, callOptions);
+    }
+
+    @java.lang.Override
+    protected XdsUpdateHealthServiceBlockingV2Stub build(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      return new XdsUpdateHealthServiceBlockingV2Stub(channel, callOptions);
+    }
+
+    /**
+     */
+    public io.grpc.testing.integration.EmptyProtos.Empty setServing(io.grpc.testing.integration.EmptyProtos.Empty request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getSetServingMethod(), getCallOptions(), request);
+    }
+
+    /**
+     */
+    public io.grpc.testing.integration.EmptyProtos.Empty setNotServing(io.grpc.testing.integration.EmptyProtos.Empty request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getSetNotServingMethod(), getCallOptions(), request);
+    }
+  }
+
+  /**
+   * A stub to allow clients to do limited synchronous rpc calls to service XdsUpdateHealthService.
+   * <pre>
+   * A service to remotely control health status of an xDS test server.
+   * </pre>
+   */
   public static final class XdsUpdateHealthServiceBlockingStub
       extends io.grpc.stub.AbstractBlockingStub<XdsUpdateHealthServiceBlockingStub> {
     private XdsUpdateHealthServiceBlockingStub(

android/build.gradle

@@ -7,20 +7,20 @@ plugins {
 description = 'gRPC: Android'
 
 android {
-    namespace 'io.grpc.android'
+    namespace = 'io.grpc.android'
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_8
         targetCompatibility JavaVersion.VERSION_1_8
     }
     compileSdkVersion 34
     defaultConfig {
-        minSdkVersion 21
+        minSdkVersion 22
         targetSdkVersion 33
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
-    lintOptions { abortOnError true }
+    lintOptions { abortOnError = true }
     publishing {
         singleVariant('release') {
             withSourcesJar()
@@ -31,7 +31,6 @@ android {
 
 repositories {
     google()
-    mavenCentral()
 }
 
 dependencies {

android/src/main/java/io/grpc/android/AndroidChannelBuilder.java

@@ -28,6 +28,7 @@ import android.util.Log;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
 import com.google.errorprone.annotations.InlineMe;
+import com.google.errorprone.annotations.concurrent.GuardedBy;
 import io.grpc.CallOptions;
 import io.grpc.ClientCall;
 import io.grpc.ConnectivityState;
@@ -41,7 +42,6 @@ import io.grpc.MethodDescriptor;
 import io.grpc.internal.GrpcUtil;
 import java.util.concurrent.TimeUnit;
 import javax.annotation.Nullable;
-import javax.annotation.concurrent.GuardedBy;
 
 /**
  * Builds a {@link ManagedChannel} that, when provided with a {@link Context}, will automatically
@@ -217,7 +217,6 @@ public final class AndroidChannelBuilder extends ForwardingChannelBuilder<Androi
         connectivityManager.registerDefaultNetworkCallback(defaultNetworkCallback);
         unregisterRunnable =
             new Runnable() {
-              @TargetApi(Build.VERSION_CODES.LOLLIPOP)
               @Override
               public void run() {
                 connectivityManager.unregisterNetworkCallback(defaultNetworkCallback);
@@ -231,7 +230,6 @@ public final class AndroidChannelBuilder extends ForwardingChannelBuilder<Androi
         context.registerReceiver(networkReceiver, networkIntentFilter);
         unregisterRunnable =
             new Runnable() {
-              @TargetApi(Build.VERSION_CODES.LOLLIPOP)
               @Override
               public void run() {
                 context.unregisterReceiver(networkReceiver);

api/BUILD.bazel

@@ -6,7 +6,6 @@ java_library(
         "src/main/java/**/*.java",
         "src/context/java/**/*.java",
     ]),
-    javacopts = ["-Xep:DoNotCall:OFF"],  # Remove once requiring Bazel 3.4.0+; allows non-final
     visibility = ["//visibility:public"],
     deps = [
         artifact("com.google.code.findbugs:jsr305"),

api/build.gradle

@@ -47,9 +47,22 @@ dependencies {
     testImplementation project(':grpc-core')
     testImplementation project(':grpc-testing')
     testImplementation libraries.guava.testlib
+    testImplementation libraries.truth
 
-    signature libraries.signature.java
-    signature libraries.signature.android
+    signature (libraries.signature.java) {
+        artifact {
+            extension = "signature"
+        }
+    }
+    signature (libraries.signature.android) {
+        artifact {
+            extension = "signature"
+        }
+    }
+}
+
+animalsniffer {
+    annotation = 'io.grpc.IgnoreJRERequirement'
 }
 
 tasks.named("javadoc").configure {

api/src/context/java/io/grpc/Deadline.java

@@ -16,8 +16,10 @@
 
 package io.grpc;
 
-import java.util.Arrays;
+import static java.util.Objects.requireNonNull;
+
 import java.util.Locale;
+import java.util.Objects;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.TimeUnit;
@@ -33,7 +35,7 @@ import java.util.concurrent.TimeUnit;
  * passed to the various components unambiguously.
  */
 public final class Deadline implements Comparable<Deadline> {
-  private static final SystemTicker SYSTEM_TICKER = new SystemTicker();
+  private static final Ticker SYSTEM_TICKER = new SystemTicker();
   // nanoTime has a range of just under 300 years. Only allow up to 100 years in the past or future
   // to prevent wraparound as long as process runs for less than ~100 years.
   private static final long MAX_OFFSET = TimeUnit.DAYS.toNanos(100 * 365);
@@ -91,7 +93,7 @@ public final class Deadline implements Comparable<Deadline> {
    * @since 1.24.0
    */
   public static Deadline after(long duration, TimeUnit units, Ticker ticker) {
-    checkNotNull(units, "units");
+    requireNonNull(units, "units");
     return new Deadline(ticker, units.toNanos(duration), true);
   }
 
@@ -191,8 +193,8 @@ public final class Deadline implements Comparable<Deadline> {
    * @return {@link ScheduledFuture} which can be used to cancel execution of the task
    */
   public ScheduledFuture<?> runOnExpiration(Runnable task, ScheduledExecutorService scheduler) {
-    checkNotNull(task, "task");
-    checkNotNull(scheduler, "scheduler");
+    requireNonNull(task, "task");
+    requireNonNull(scheduler, "scheduler");
     return scheduler.schedule(task, deadlineNanos - ticker.nanoTime(), TimeUnit.NANOSECONDS);
   }
 
@@ -225,37 +227,27 @@ public final class Deadline implements Comparable<Deadline> {
   @Override
   public int compareTo(Deadline that) {
     checkTicker(that);
-    long diff = this.deadlineNanos - that.deadlineNanos;
-    if (diff < 0) {
-      return -1;
-    } else if (diff > 0) {
-      return 1;
-    }
-    return 0;
+    return Long.compare(this.deadlineNanos, that.deadlineNanos);
   }
 
   @Override
   public int hashCode() {
-    return Arrays.asList(this.ticker, this.deadlineNanos).hashCode();
+    return Objects.hash(this.ticker, this.deadlineNanos);
   }
 
   @Override
-  public boolean equals(final Object o) {
-    if (o == this) {
+  public boolean equals(final Object object) {
+    if (object == this) {
       return true;
     }
-    if (!(o instanceof Deadline)) {
+    if (!(object instanceof Deadline)) {
       return false;
     }
-
-    final Deadline other = (Deadline) o;
-    if (this.ticker == null ? other.ticker != null : this.ticker != other.ticker) {
+    final Deadline that = (Deadline) object;
+    if (this.ticker == null ? that.ticker != null : this.ticker != that.ticker) {
       return false;
     }
-    if (this.deadlineNanos != other.deadlineNanos) {
-      return false;
-    }
-    return true;
+    return this.deadlineNanos == that.deadlineNanos;
   }
 
   /**
@@ -275,24 +267,17 @@ public final class Deadline implements Comparable<Deadline> {
    * @since 1.24.0
    */
   public abstract static class Ticker {
-    /** Returns the number of nanoseconds since this source's epoch. */
+    /** Returns the number of nanoseconds elapsed since this ticker's reference point in time. */
     public abstract long nanoTime();
   }
 
-  private static class SystemTicker extends Ticker {
+  private static final class SystemTicker extends Ticker {
     @Override
     public long nanoTime() {
       return System.nanoTime();
     }
   }
 
-  private static <T> T checkNotNull(T reference, Object errorMessage) {
-    if (reference == null) {
-      throw new NullPointerException(String.valueOf(errorMessage));
-    }
-    return reference;
-  }
-
   private void checkTicker(Deadline other) {
     if (ticker != other.ticker) {
       throw new AssertionError(

api/src/main/java/io/grpc/CallOptions.java

@@ -17,16 +17,18 @@
 package io.grpc;
 
 import static com.google.common.base.Preconditions.checkArgument;
+import static io.grpc.TimeUtils.convertToNanos;
 
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Preconditions;
+import com.google.errorprone.annotations.CheckReturnValue;
+import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.Executor;
 import java.util.concurrent.TimeUnit;
-import javax.annotation.CheckReturnValue;
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 
@@ -176,6 +178,11 @@ public final class CallOptions {
     return withDeadline(Deadline.after(duration, unit));
   }
 
+  @ExperimentalApi("https://github.com/grpc/grpc-java/issues/11657")
+  public CallOptions withDeadlineAfter(Duration duration) {
+    return withDeadlineAfter(convertToNanos(duration), TimeUnit.NANOSECONDS);
+  }
+
   /**
    * Returns the deadline or {@code null} if the deadline is not set.
    */

api/src/main/java/io/grpc/ClientCall.java

@@ -67,7 +67,7 @@ import javax.annotation.Nullable;
  * manner, and notifies gRPC library to receive additional response after one is consumed by
  * a fictional <code>processResponse()</code>.
  *
- * <p><pre>
+ * <pre>
  *   call = channel.newCall(bidiStreamingMethod, callOptions);
  *   listener = new ClientCall.Listener&lt;FooResponse&gt;() {
  *     &#64;Override

api/src/main/java/io/grpc/ConfiguratorRegistry.java

@@ -16,10 +16,10 @@
 
 package io.grpc;
 
+import com.google.errorprone.annotations.concurrent.GuardedBy;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
-import javax.annotation.concurrent.GuardedBy;
 
 /**
  * A registry for {@link Configurator} instances.
@@ -33,9 +33,9 @@ final class ConfiguratorRegistry {
   @GuardedBy("this")
   private boolean wasConfiguratorsSet;
   @GuardedBy("this")
-  private boolean configFrozen;
-  @GuardedBy("this")
   private List<Configurator> configurators = Collections.emptyList();
+  @GuardedBy("this")
+  private int configuratorsCallCountBeforeSet = 0;
 
   ConfiguratorRegistry() {}
 
@@ -56,11 +56,10 @@ final class ConfiguratorRegistry {
    * @throws IllegalStateException if this method is called more than once
    */
   public synchronized void setConfigurators(List<? extends Configurator> configurators) {
-    if (configFrozen) {
+    if (wasConfiguratorsSet) {
       throw new IllegalStateException("Configurators are already set");
     }
     this.configurators = Collections.unmodifiableList(new ArrayList<>(configurators));
-    configFrozen = true;
     wasConfiguratorsSet = true;
   }
 
@@ -68,10 +67,20 @@ final class ConfiguratorRegistry {
    * Returns a list of the configurators in this registry.
    */
   public synchronized List<Configurator> getConfigurators() {
-    configFrozen = true;
+    if (!wasConfiguratorsSet) {
+      configuratorsCallCountBeforeSet++;
+    }
     return configurators;
   }
 
+  /**
+   * Returns the number of times getConfigurators() was called before
+   * setConfigurators() was successfully invoked.
+   */
+  public synchronized int getConfiguratorsCallCountBeforeSet() {
+    return configuratorsCallCountBeforeSet;
+  }
+
   public synchronized boolean wasSetConfiguratorsCalled() {
     return wasConfiguratorsSet;
   }

api/src/main/java/io/grpc/ForwardingChannelBuilder2.java

@@ -263,6 +263,12 @@ public abstract class ForwardingChannelBuilder2<T extends ManagedChannelBuilder<
     return thisT();
   }
 
+  @Override
+  public <X> T setNameResolverArg(NameResolver.Args.Key<X> key, X value) {
+    delegate().setNameResolverArg(key, value);
+    return thisT();
+  }
+
   /**
    * Returns the {@link ManagedChannel} built by the delegate by default. Overriding method can
    * return different value.

api/src/main/java/io/grpc/IgnoreJRERequirement.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2024 The gRPC Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.grpc;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Target;
+
+/**
+ * Disables Animal Sniffer's signature checking. This is our own package-private version to avoid
+ * dependening on animalsniffer-annotations.
+ *
+ * <p>FIELD is purposefully not supported, as Android wouldn't be able to ignore a field. Instead,
+ * the entire class would need to be avoided on Android.
+ */
+@Target({ElementType.METHOD, ElementType.CONSTRUCTOR, ElementType.TYPE})
+@interface IgnoreJRERequirement {}

api/src/main/java/io/grpc/InternalConfigSelector.java

@@ -35,7 +35,7 @@ public abstract class InternalConfigSelector {
       = Attributes.Key.create("internal:io.grpc.config-selector");
 
   // Use PickSubchannelArgs for SelectConfigArgs for now. May change over time.
-  /** Selects the config for an PRC. */
+  /** Selects the config for an RPC. */
   public abstract Result selectConfig(LoadBalancer.PickSubchannelArgs args);
 
   public static final class Result {

api/src/main/java/io/grpc/InternalConfiguratorRegistry.java

@@ -48,4 +48,8 @@ public final class InternalConfiguratorRegistry {
   public static boolean wasSetConfiguratorsCalled() {
     return ConfiguratorRegistry.getDefaultRegistry().wasSetConfiguratorsCalled();
   }
+
+  public static int getConfiguratorsCallCountBeforeSet() {
+    return ConfiguratorRegistry.getDefaultRegistry().getConfiguratorsCallCountBeforeSet();
+  }
 }

api/src/main/java/io/grpc/InternalStatus.java

@@ -38,12 +38,11 @@ public final class InternalStatus {
   public static final Metadata.Key<Status> CODE_KEY = Status.CODE_KEY;
 
   /**
-   * Create a new {@link StatusRuntimeException} with the internal option of skipping the filling
-   * of the stack trace.
+   * Create a new {@link StatusRuntimeException} skipping the filling of the stack trace.
    */
   @Internal
-  public static final StatusRuntimeException asRuntimeException(Status status,
-      @Nullable Metadata trailers, boolean fillInStackTrace) {
-    return new StatusRuntimeException(status, trailers, fillInStackTrace);
+  public static StatusRuntimeException asRuntimeExceptionWithoutStacktrace(Status status,
+      @Nullable Metadata trailers) {
+    return new InternalStatusRuntimeException(status, trailers);
   }
 }

api/src/main/java/io/grpc/InternalStatusRuntimeException.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2015 The gRPC Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.grpc;
+
+import javax.annotation.Nullable;
+
+/**
+ * StatusRuntimeException without stack trace, implemented as a subclass, as the
+ * {@code String, Throwable, boolean, boolean} constructor is not available in the supported
+ * version of Android.
+ *
+ * @see StatusRuntimeException
+ */
+class InternalStatusRuntimeException extends StatusRuntimeException {
+  private static final long serialVersionUID = 0;
+
+  public InternalStatusRuntimeException(Status status, @Nullable Metadata trailers) {
+    super(status, trailers);
+  }
+
+  @Override
+  public synchronized Throwable fillInStackTrace() {
+    return this;
+  }
+}

api/src/main/java/io/grpc/InternalTimeUtils.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2024 The gRPC Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.grpc;
+
+import java.time.Duration;
+
+@Internal
+public final class InternalTimeUtils {
+  public static long convert(Duration duration) {
+    return TimeUtils.convertToNanos(duration);
+  }
+}

api/src/main/java/io/grpc/LoadBalancer.java

@@ -212,7 +212,7 @@ public abstract class LoadBalancer {
    *
    * @since 1.21.0
    */
-  @ExperimentalApi("https://github.com/grpc/grpc-java/issues/1771")
+  @ExperimentalApi("https://github.com/grpc/grpc-java/issues/11657")
   public static final class ResolvedAddresses {
     private final List<EquivalentAddressGroup> addresses;
     @NameResolver.ResolutionResultAttr
@@ -452,18 +452,6 @@ public abstract class LoadBalancer {
      * @since 1.3.0
      */
     public abstract PickResult pickSubchannel(PickSubchannelArgs args);
-
-    /**
-     * Tries to establish connections now so that the upcoming RPC may then just pick a ready
-     * connection without having to connect first.
-     *
-     * <p>No-op if unsupported.
-     *
-     * @deprecated override {@link LoadBalancer#requestConnection} instead.
-     * @since 1.11.0
-     */
-    @Deprecated
-    public void requestConnection() {}
   }
 
   /**
@@ -552,6 +540,7 @@ public abstract class LoadBalancer {
     private final Status status;
     // True if the result is created by withDrop()
     private final boolean drop;
+    @Nullable private final String authorityOverride;
 
     private PickResult(
         @Nullable Subchannel subchannel, @Nullable ClientStreamTracer.Factory streamTracerFactory,
@@ -560,6 +549,17 @@ public abstract class LoadBalancer {
       this.streamTracerFactory = streamTracerFactory;
       this.status = checkNotNull(status, "status");
       this.drop = drop;
+      this.authorityOverride = null;
+    }
+
+    private PickResult(
+        @Nullable Subchannel subchannel, @Nullable ClientStreamTracer.Factory streamTracerFactory,
+        Status status, boolean drop, @Nullable String authorityOverride) {
+      this.subchannel = subchannel;
+      this.streamTracerFactory = streamTracerFactory;
+      this.status = checkNotNull(status, "status");
+      this.drop = drop;
+      this.authorityOverride = authorityOverride;
     }
 
     /**
@@ -639,6 +639,19 @@ public abstract class LoadBalancer {
           false);
     }
 
+    /**
+     * Same as {@code withSubchannel(subchannel, streamTracerFactory)} but with an authority name
+     * to override in the host header.
+     */
+    @ExperimentalApi("https://github.com/grpc/grpc-java/issues/11656")
+    public static PickResult withSubchannel(
+        Subchannel subchannel, @Nullable ClientStreamTracer.Factory streamTracerFactory,
+        @Nullable String authorityOverride) {
+      return new PickResult(
+          checkNotNull(subchannel, "subchannel"), streamTracerFactory, Status.OK,
+          false, authorityOverride);
+    }
+
     /**
      * Equivalent to {@code withSubchannel(subchannel, null)}.
      *
@@ -682,6 +695,13 @@ public abstract class LoadBalancer {
       return NO_RESULT;
     }
 
+    /** Returns the authority override if any. */
+    @ExperimentalApi("https://github.com/grpc/grpc-java/issues/11656")
+    @Nullable
+    public String getAuthorityOverride() {
+      return authorityOverride;
+    }
+
     /**
      * The Subchannel if this result was created by {@link #withSubchannel withSubchannel()}, or
      * null otherwise.
@@ -736,6 +756,7 @@ public abstract class LoadBalancer {
           .add("streamTracerFactory", streamTracerFactory)
           .add("status", status)
           .add("drop", drop)
+          .add("authority-override", authorityOverride)
           .toString();
     }
 
@@ -1000,8 +1021,8 @@ public abstract class LoadBalancer {
     }
 
     /**
-     * Out-of-band channel for LoadBalancer’s own RPC needs, e.g., talking to an external
-     * load-balancer service.
+     * Create an out-of-band channel for the LoadBalancer’s own RPC needs, e.g., talking to an
+     * external load-balancer service.
      *
      * <p>The LoadBalancer is responsible for closing unused OOB channels, and closing all OOB
      * channels within {@link #shutdown}.
@@ -1011,7 +1032,12 @@ public abstract class LoadBalancer {
     public abstract ManagedChannel createOobChannel(EquivalentAddressGroup eag, String authority);
 
     /**
-     * Accept a list of EAG for multiple authorities: https://github.com/grpc/grpc-java/issues/4618
+     * Create an out-of-band channel for the LoadBalancer's own RPC needs, e.g., talking to an
+     * external load-balancer service. This version of the method allows multiple EAGs, so different
+     * addresses can have different authorities.
+     *
+     * <p>The LoadBalancer is responsible for closing unused OOB channels, and closing all OOB
+     * channels within {@link #shutdown}.
      * */
     public ManagedChannel createOobChannel(List<EquivalentAddressGroup> eag,
         String authority) {
@@ -1163,6 +1189,10 @@ public abstract class LoadBalancer {
      * Returns a {@link SynchronizationContext} that runs tasks in the same Synchronization Context
      * as that the callback methods on the {@link LoadBalancer} interface are run in.
      *
+     * <p>Work added to the synchronization context might not run immediately, so LB implementations
+     * must be careful to ensure that any assumptions still hold when it is executed. In particular,
+     * the LB might have been shut down or subchannels might have changed state.
+     *
      * <p>Pro-tip: in order to call {@link SynchronizationContext#schedule}, you need to provide a
      * {@link ScheduledExecutorService}.  {@link #getScheduledExecutorService} is provided for your
      * convenience.

api/src/main/java/io/grpc/ManagedChannelBuilder.java

@@ -633,6 +633,23 @@ public abstract class ManagedChannelBuilder<T extends ManagedChannelBuilder<T>>
     throw new UnsupportedOperationException();
   }
 
+  /**
+   * Provides a "custom" argument for the {@link NameResolver}, if applicable, replacing any 'value'
+   * previously provided for 'key'.
+   *
+   * <p>NB: If the selected {@link NameResolver} does not understand 'key', or target URI resolution
+   * isn't needed at all, your custom argument will be silently ignored.
+   *
+   * <p>See {@link NameResolver.Args#getArg(NameResolver.Args.Key)} for more.
+   *
+   * @param key identifies the argument in a type-safe manner
+   * @param value the argument itself
+   * @return this
+   */
+  @ExperimentalApi("https://github.com/grpc/grpc-java/issues/1770")
+  public <X> T setNameResolverArg(NameResolver.Args.Key<X> key, X value) {
+    throw new UnsupportedOperationException();
+  }
 
   /**
    * Builds a channel using the given parameters.

api/src/main/java/io/grpc/ManagedChannelRegistry.java

@@ -18,6 +18,7 @@ package io.grpc;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
+import com.google.errorprone.annotations.concurrent.GuardedBy;
 import java.net.SocketAddress;
 import java.net.URI;
 import java.net.URISyntaxException;
@@ -30,7 +31,6 @@ import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.logging.Level;
 import java.util.logging.Logger;
-import javax.annotation.concurrent.GuardedBy;
 import javax.annotation.concurrent.ThreadSafe;
 
 /**

api/src/main/java/io/grpc/Metadata.java

@@ -22,6 +22,8 @@ import static java.nio.charset.StandardCharsets.US_ASCII;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
+import com.google.common.collect.Maps;
+import com.google.common.collect.Sets;
 import com.google.common.io.BaseEncoding;
 import com.google.common.io.ByteStreams;
 import java.io.ByteArrayInputStream;
@@ -32,8 +34,6 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.BitSet;
 import java.util.Collections;
-import java.util.HashMap;
-import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Locale;
@@ -325,7 +325,7 @@ public final class Metadata {
     if (isEmpty()) {
       return Collections.emptySet();
     }
-    Set<String> ks = new HashSet<>(size);
+    Set<String> ks = Sets.newHashSetWithExpectedSize(size);
     for (int i = 0; i < size; i++) {
       ks.add(new String(name(i), 0 /* hibyte */));
     }
@@ -526,7 +526,7 @@ public final class Metadata {
   public void merge(Metadata other, Set<Key<?>> keys) {
     Preconditions.checkNotNull(other, "other");
     // Use ByteBuffer for equals and hashCode.
-    Map<ByteBuffer, Key<?>> asciiKeys = new HashMap<>(keys.size());
+    Map<ByteBuffer, Key<?>> asciiKeys = Maps.newHashMapWithExpectedSize(keys.size());
     for (Key<?> key : keys) {
       asciiKeys.put(ByteBuffer.wrap(key.asciiName()), key);
     }

api/src/main/java/io/grpc/MethodDescriptor.java

@@ -20,9 +20,9 @@ import static com.google.common.base.Preconditions.checkNotNull;
 
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Preconditions;
+import com.google.errorprone.annotations.CheckReturnValue;
 import java.io.InputStream;
 import java.util.concurrent.atomic.AtomicReferenceArray;
-import javax.annotation.CheckReturnValue;
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 

api/src/main/java/io/grpc/MetricInstrumentRegistry.java

@@ -21,12 +21,12 @@ import static com.google.common.base.Preconditions.checkNotNull;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Strings;
+import com.google.errorprone.annotations.concurrent.GuardedBy;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
-import javax.annotation.concurrent.GuardedBy;
 
 /**
  * A registry for globally registered metric instruments.

api/src/main/java/io/grpc/NameResolver.java

@@ -28,11 +28,13 @@ import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.net.URI;
 import java.util.Collections;
+import java.util.IdentityHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.Executor;
 import java.util.concurrent.ScheduledExecutorService;
 import javax.annotation.Nullable;
+import javax.annotation.concurrent.Immutable;
 import javax.annotation.concurrent.ThreadSafe;
 
 /**
@@ -219,13 +221,15 @@ public abstract class NameResolver {
     @Override
     @Deprecated
     @InlineMe(
-        replacement = "this.onResult2(ResolutionResult.newBuilder().setAddressesOrError("
+        replacement = "this.onResult(ResolutionResult.newBuilder().setAddressesOrError("
             + "StatusOr.fromValue(servers)).setAttributes(attributes).build())",
         imports = {"io.grpc.NameResolver.ResolutionResult", "io.grpc.StatusOr"})
     public final void onAddresses(
         List<EquivalentAddressGroup> servers, @ResolutionResultAttr Attributes attributes) {
       // TODO(jihuncho) need to promote Listener2 if we want to use ConfigOrError
-      onResult2(
+      // Calling onResult and not onResult2 because onResult2 can only be called from a
+      // synchronization context.
+      onResult(
           ResolutionResult.newBuilder().setAddressesOrError(
               StatusOr.fromValue(servers)).setAttributes(attributes).build());
     }
@@ -235,6 +239,9 @@ public abstract class NameResolver {
      * {@link ResolutionResult#getAddressesOrError()} is empty, {@link #onError(Status)} will be
      * called.
      *
+     * <p>Newer NameResolver implementations should prefer calling onResult2. This method exists to
+     * facilitate older {@link Listener} implementations to migrate to {@link Listener2}.
+     *
      * @param resolutionResult the resolved server addresses, attributes, and Service Config.
      * @since 1.21.0
      */
@@ -244,6 +251,10 @@ public abstract class NameResolver {
      * Handles a name resolving error from the resolver. The listener is responsible for eventually
      * invoking {@link NameResolver#refresh()} to re-attempt resolution.
      *
+     * <p>New NameResolver implementations should prefer calling onResult2 which will have the
+     * address resolution error in {@link ResolutionResult}'s addressesOrError. This method exists
+     * to facilitate older implementations using {@link Listener} to migrate to {@link Listener2}.
+     *
      * @param error a non-OK status
      * @since 1.21.0
      */
@@ -251,9 +262,14 @@ public abstract class NameResolver {
     public abstract void onError(Status error);
 
     /**
-     * Handles updates on resolved addresses and attributes.
+     * Handles updates on resolved addresses and attributes. Must be called from the same
+     * {@link SynchronizationContext} available in {@link NameResolver.Args} that is passed
+     * from the channel.
      *
-     * @param resolutionResult the resolved server addresses, attributes, and Service Config.
+     * @param resolutionResult the resolved server addresses or error in address resolution,
+     *     attributes, and Service Config or error
+     * @return status indicating whether the resolutionResult was accepted by the listener,
+     *     typically the result from a load balancer.
      * @since 1.66
      */
     public Status onResult2(ResolutionResult resolutionResult) {
@@ -271,10 +287,20 @@ public abstract class NameResolver {
   @Documented
   public @interface ResolutionResultAttr {}
 
+  @ExperimentalApi("https://github.com/grpc/grpc-java/issues/11989")
+  @ResolutionResultAttr
+  public static final Attributes.Key<String> ATTR_BACKEND_SERVICE =
+      Attributes.Key.create("io.grpc.NameResolver.ATTR_BACKEND_SERVICE");
+
   /**
    * Information that a {@link Factory} uses to create a {@link NameResolver}.
    *
-   * <p>Note this class doesn't override neither {@code equals()} nor {@code hashCode()}.
+   * <p>Args applicable to all {@link NameResolver}s are defined here using ordinary setters and
+   * getters. This container can also hold externally-defined "custom" args that aren't so widely
+   * useful or that would be inappropriate dependencies for this low level API. See {@link
+   * Args#getArg} for more.
+   *
+   * <p>Note this class overrides neither {@code equals()} nor {@code hashCode()}.
    *
    * @since 1.21.0
    */
@@ -288,24 +314,23 @@ public abstract class NameResolver {
     @Nullable private final ChannelLogger channelLogger;
     @Nullable private final Executor executor;
     @Nullable private final String overrideAuthority;
+    @Nullable private final MetricRecorder metricRecorder;
+    @Nullable private final NameResolverRegistry nameResolverRegistry;
+    @Nullable private final IdentityHashMap<Key<?>, Object> customArgs;
 
-    private Args(
-        Integer defaultPort,
-        ProxyDetector proxyDetector,
-        SynchronizationContext syncContext,
-        ServiceConfigParser serviceConfigParser,
-        @Nullable ScheduledExecutorService scheduledExecutorService,
-        @Nullable ChannelLogger channelLogger,
-        @Nullable Executor executor,
-        @Nullable String overrideAuthority) {
-      this.defaultPort = checkNotNull(defaultPort, "defaultPort not set");
-      this.proxyDetector = checkNotNull(proxyDetector, "proxyDetector not set");
-      this.syncContext = checkNotNull(syncContext, "syncContext not set");
-      this.serviceConfigParser = checkNotNull(serviceConfigParser, "serviceConfigParser not set");
-      this.scheduledExecutorService = scheduledExecutorService;
-      this.channelLogger = channelLogger;
-      this.executor = executor;
-      this.overrideAuthority = overrideAuthority;
+    private Args(Builder builder) {
+      this.defaultPort = checkNotNull(builder.defaultPort, "defaultPort not set");
+      this.proxyDetector = checkNotNull(builder.proxyDetector, "proxyDetector not set");
+      this.syncContext = checkNotNull(builder.syncContext, "syncContext not set");
+      this.serviceConfigParser =
+          checkNotNull(builder.serviceConfigParser, "serviceConfigParser not set");
+      this.scheduledExecutorService = builder.scheduledExecutorService;
+      this.channelLogger = builder.channelLogger;
+      this.executor = builder.executor;
+      this.overrideAuthority = builder.overrideAuthority;
+      this.metricRecorder = builder.metricRecorder;
+      this.nameResolverRegistry = builder.nameResolverRegistry;
+      this.customArgs = cloneCustomArgs(builder.customArgs);
     }
 
     /**
@@ -314,6 +339,7 @@ public abstract class NameResolver {
      *
      * @since 1.21.0
      */
+    // <p>TODO: Only meaningful for InetSocketAddress producers. Make this a custom arg?
     public int getDefaultPort() {
       return defaultPort;
     }
@@ -366,6 +392,30 @@ public abstract class NameResolver {
       return serviceConfigParser;
     }
 
+    /**
+     * Returns the value of a custom arg named 'key', or {@code null} if it's not set.
+     *
+     * <p>While ordinary {@link Args} should be universally useful and meaningful, custom arguments
+     * can apply just to resolvers of a certain URI scheme, just to resolvers producing a particular
+     * type of {@link java.net.SocketAddress}, or even an individual {@link NameResolver} subclass.
+     * Custom args are identified by an instance of {@link Args.Key} which should be a constant
+     * defined in a java package and class appropriate for the argument's scope.
+     *
+     * <p>{@link Args} are normally reserved for information in *support* of name resolution, not
+     * the name to be resolved itself. However, there are rare cases where all or part of the target
+     * name can't be represented by any standard URI scheme or can't be encoded as a String at all.
+     * Custom args, in contrast, can hold arbitrary Java types, making them a useful work around in
+     * these cases.
+     *
+     * <p>Custom args can also be used simply to avoid adding inappropriate deps to the low level
+     * io.grpc package.
+     */
+    @SuppressWarnings("unchecked") // Cast is safe because all put()s go through the setArg() API.
+    @Nullable
+    public <T> T getArg(Key<T> key) {
+      return customArgs != null ? (T) customArgs.get(key) : null;
+    }
+
     /**
      * Returns the {@link ChannelLogger} for the Channel served by this NameResolver.
      *
@@ -403,6 +453,26 @@ public abstract class NameResolver {
       return overrideAuthority;
     }
 
+    /**
+     * Returns the {@link MetricRecorder} that the channel uses to record metrics.
+     */
+    @Nullable
+    public MetricRecorder getMetricRecorder() {
+      return metricRecorder;
+    }
+
+    /**
+     * Returns the {@link NameResolverRegistry} that the Channel uses to look for {@link
+     * NameResolver}s.
+     *
+     * @since 1.74.0
+     */
+    public NameResolverRegistry getNameResolverRegistry() {
+      if (nameResolverRegistry == null) {
+        throw new IllegalStateException("NameResolverRegistry is not set in Builder");
+      }
+      return nameResolverRegistry;
+    }
 
     @Override
     public String toString() {
@@ -411,10 +481,13 @@ public abstract class NameResolver {
           .add("proxyDetector", proxyDetector)
           .add("syncContext", syncContext)
           .add("serviceConfigParser", serviceConfigParser)
+          .add("customArgs", customArgs)
           .add("scheduledExecutorService", scheduledExecutorService)
           .add("channelLogger", channelLogger)
           .add("executor", executor)
           .add("overrideAuthority", overrideAuthority)
+          .add("metricRecorder", metricRecorder)
+          .add("nameResolverRegistry", nameResolverRegistry)
           .toString();
     }
 
@@ -433,6 +506,9 @@ public abstract class NameResolver {
       builder.setChannelLogger(channelLogger);
       builder.setOffloadExecutor(executor);
       builder.setOverrideAuthority(overrideAuthority);
+      builder.setMetricRecorder(metricRecorder);
+      builder.setNameResolverRegistry(nameResolverRegistry);
+      builder.customArgs = cloneCustomArgs(customArgs);
       return builder;
     }
 
@@ -459,6 +535,9 @@ public abstract class NameResolver {
       private ChannelLogger channelLogger;
       private Executor executor;
       private String overrideAuthority;
+      private MetricRecorder metricRecorder;
+      private NameResolverRegistry nameResolverRegistry;
+      private IdentityHashMap<Key<?>, Object> customArgs;
 
       Builder() {
       }
@@ -545,16 +624,75 @@ public abstract class NameResolver {
         return this;
       }
 
+      /** See {@link Args#getArg(Key)}. */
+      public <T> Builder setArg(Key<T> key, T value) {
+        checkNotNull(key, "key");
+        checkNotNull(value, "value");
+        if (customArgs == null) {
+          customArgs = new IdentityHashMap<>();
+        }
+        customArgs.put(key, value);
+        return this;
+      }
+
+      /**
+       * See {@link Args#getMetricRecorder()}. This is an optional field.
+       */
+      public Builder setMetricRecorder(MetricRecorder metricRecorder) {
+        this.metricRecorder = metricRecorder;
+        return this;
+      }
+
+      /**
+       * See {@link Args#getNameResolverRegistry}.  This is an optional field.
+       *
+       * @since 1.74.0
+       */
+      public Builder setNameResolverRegistry(NameResolverRegistry registry) {
+        this.nameResolverRegistry = registry;
+        return this;
+      }
+
       /**
        * Builds an {@link Args}.
        *
        * @since 1.21.0
        */
       public Args build() {
-        return
-            new Args(
-                defaultPort, proxyDetector, syncContext, serviceConfigParser,
-                scheduledExecutorService, channelLogger, executor, overrideAuthority);
+        return new Args(this);
+      }
+    }
+
+    /**
+     * Identifies an externally-defined custom argument that can be stored in {@link Args}.
+     *
+     * <p>Uses reference equality so keys should be defined as global constants.
+     *
+     * @param <T> type of values that can be stored under this key
+     */
+    @Immutable
+    @SuppressWarnings("UnusedTypeParameter")
+    public static final class Key<T> {
+      private final String debugString;
+
+      private Key(String debugString) {
+        this.debugString = debugString;
+      }
+
+      @Override
+      public String toString() {
+        return debugString;
+      }
+
+      /**
+       * Creates a new instance of {@link Key}.
+       *
+       * @param debugString a string used to describe the key, used for debugging.
+       * @param <T> Key type
+       * @return a new instance of Key
+       */
+      public static <T> Key<T> create(String debugString) {
+        return new Key<>(debugString);
       }
     }
   }
@@ -852,4 +990,10 @@ public abstract class NameResolver {
       }
     }
   }
+
+  @Nullable
+  private static IdentityHashMap<Args.Key<?>, Object> cloneCustomArgs(
+          @Nullable IdentityHashMap<Args.Key<?>, Object> customArgs) {
+    return customArgs != null ? new IdentityHashMap<>(customArgs) : null;
+  }
 }

api/src/main/java/io/grpc/NameResolverRegistry.java

@@ -20,6 +20,7 @@ import static com.google.common.base.Preconditions.checkArgument;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.ImmutableMap;
+import com.google.errorprone.annotations.concurrent.GuardedBy;
 import java.net.URI;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -31,7 +32,6 @@ import java.util.Map;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import javax.annotation.Nullable;
-import javax.annotation.concurrent.GuardedBy;
 import javax.annotation.concurrent.ThreadSafe;
 
 /**
@@ -166,6 +166,11 @@ public final class NameResolverRegistry {
     } catch (ClassNotFoundException e) {
       logger.log(Level.FINE, "Unable to find DNS NameResolver", e);
     }
+    try {
+      list.add(Class.forName("io.grpc.binder.internal.IntentNameResolverProvider"));
+    } catch (ClassNotFoundException e) {
+      logger.log(Level.FINE, "Unable to find IntentNameResolverProvider", e);
+    }
     return Collections.unmodifiableList(list);
   }
 

api/src/main/java/io/grpc/ServerRegistry.java

@@ -18,6 +18,7 @@ package io.grpc;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
+import com.google.errorprone.annotations.concurrent.GuardedBy;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Comparator;
@@ -25,7 +26,6 @@ import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.logging.Level;
 import java.util.logging.Logger;
-import javax.annotation.concurrent.GuardedBy;
 import javax.annotation.concurrent.ThreadSafe;
 
 /**

api/src/main/java/io/grpc/Status.java

@@ -23,6 +23,7 @@ import static java.nio.charset.StandardCharsets.UTF_8;
 
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Objects;
+import com.google.errorprone.annotations.CheckReturnValue;
 import io.grpc.Metadata.TrustedAsciiMarshaller;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
@@ -30,7 +31,6 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.TreeMap;
-import javax.annotation.CheckReturnValue;
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 

api/src/main/java/io/grpc/StatusException.java

@@ -44,12 +44,7 @@ public class StatusException extends Exception {
    * @since 1.0.0
    */
   public StatusException(Status status, @Nullable Metadata trailers) {
-    this(status, trailers, /*fillInStackTrace=*/ true);
-  }
-
-  StatusException(Status status, @Nullable Metadata trailers, boolean fillInStackTrace) {
-    super(Status.formatThrowableMessage(status), status.getCause(),
-            /* enableSuppression */ true, /* writableStackTrace */fillInStackTrace);
+    super(Status.formatThrowableMessage(status), status.getCause());
     this.status = status;
     this.trailers = trailers;
   }

api/src/main/java/io/grpc/StatusOr.java

@@ -66,6 +66,14 @@ public class StatusOr<T> {
     return status == null ? Status.OK : status;
   }
 
+  /**
+   * Note that StatusOr containing statuses, the equality comparision is delegated to
+   * {@link Status#equals} which just does a reference equality check because equality on
+   * Statuses is not well defined.
+   * Instead, do comparison based on their Code with {@link Status#getCode}.  The description and
+   * cause of the Status are unlikely to be stable, and additional fields may be added to Status
+   * in the future.
+   */
   @Override
   public boolean equals(Object other) {
     if (!(other instanceof StatusOr)) {

api/src/main/java/io/grpc/StatusRuntimeException.java

@@ -45,12 +45,7 @@ public class StatusRuntimeException extends RuntimeException {
    * @since 1.0.0
    */
   public StatusRuntimeException(Status status, @Nullable Metadata trailers) {
-    this(status, trailers, /*fillInStackTrace=*/ true);
-  }
-
-  StatusRuntimeException(Status status, @Nullable Metadata trailers, boolean fillInStackTrace) {
-    super(Status.formatThrowableMessage(status), status.getCause(),
-            /* enable suppressions */ true, /* writableStackTrace */ fillInStackTrace);
+    super(Status.formatThrowableMessage(status), status.getCause());
     this.status = status;
     this.trailers = trailers;
   }

api/src/main/java/io/grpc/SynchronizationContext.java

@@ -18,8 +18,10 @@ package io.grpc;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkState;
+import static io.grpc.TimeUtils.convertToNanos;
 
 import java.lang.Thread.UncaughtExceptionHandler;
+import java.time.Duration;
 import java.util.Queue;
 import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.Executor;
@@ -162,6 +164,12 @@ public final class SynchronizationContext implements Executor {
     return new ScheduledHandle(runnable, future);
   }
 
+  @ExperimentalApi("https://github.com/grpc/grpc-java/issues/11657")
+  public final ScheduledHandle schedule(
+      final Runnable task, Duration delay, ScheduledExecutorService timerService) {
+    return schedule(task, convertToNanos(delay), TimeUnit.NANOSECONDS, timerService);
+  }
+
   /**
    * Schedules a task to be added and run via {@link #execute} after an initial delay and then
    * repeated after the delay until cancelled.
@@ -193,6 +201,14 @@ public final class SynchronizationContext implements Executor {
     return new ScheduledHandle(runnable, future);
   }
 
+  @ExperimentalApi("https://github.com/grpc/grpc-java/issues/11657")
+  public final ScheduledHandle scheduleWithFixedDelay(
+      final Runnable task, Duration initialDelay, Duration delay,
+      ScheduledExecutorService timerService) {
+    return scheduleWithFixedDelay(task, convertToNanos(initialDelay), convertToNanos(delay),
+        TimeUnit.NANOSECONDS, timerService);
+  }
+
 
   private static class ManagedRunnable implements Runnable {
     final Runnable task;
@@ -246,4 +262,4 @@ public final class SynchronizationContext implements Executor {
       return !(runnable.hasStarted || runnable.isCancelled);
     }
   }
-}
+}

api/src/main/java/io/grpc/TimeUtils.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2024 The gRPC Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.grpc;
+
+import java.time.Duration;
+
+final class TimeUtils {
+  private TimeUtils() {}
+
+  @IgnoreJRERequirement
+  static long convertToNanos(Duration duration) {
+    try {
+      return duration.toNanos();
+    } catch (ArithmeticException tooBig) {
+      return duration.isNegative() ? Long.MIN_VALUE : Long.MAX_VALUE;
+    }
+  }
+}

api/src/test/java/io/grpc/CallOptionsTest.java

@@ -32,6 +32,7 @@ import static org.mockito.Mockito.mock;
 import com.google.common.base.Objects;
 import io.grpc.ClientStreamTracer.StreamInfo;
 import io.grpc.internal.SerializingExecutor;
+import java.time.Duration;
 import java.util.concurrent.Executor;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -150,6 +151,15 @@ public class CallOptionsTest {
     assertAbout(deadline()).that(actual).isWithin(10, MILLISECONDS).of(expected);
   }
 
+  @Test
+  @IgnoreJRERequirement
+  public void withDeadlineAfterDuration() {
+    Deadline actual = CallOptions.DEFAULT.withDeadlineAfter(Duration.ofMinutes(1L)).getDeadline();
+    Deadline expected = Deadline.after(1, MINUTES);
+
+    assertAbout(deadline()).that(actual).isWithin(10, MILLISECONDS).of(expected);
+  }
+
   @Test
   public void toStringMatches_noDeadline_default() {
     String actual = allSet

api/src/test/java/io/grpc/ConfiguratorRegistryTest.java

@@ -85,14 +85,12 @@ public class ConfiguratorRegistryTest {
     @Override
     public void run() {
       assertThat(ConfiguratorRegistry.getDefaultRegistry().getConfigurators()).isEmpty();
-
-      try {
-        ConfiguratorRegistry.getDefaultRegistry()
-            .setConfigurators(Arrays.asList(new NoopConfigurator()));
-        fail("should have failed for invoking set call after get is already called");
-      } catch (IllegalStateException e) {
-        assertThat(e).hasMessageThat().isEqualTo("Configurators are already set");
-      }
+      NoopConfigurator noopConfigurator = new NoopConfigurator();
+      ConfiguratorRegistry.getDefaultRegistry()
+              .setConfigurators(Arrays.asList(noopConfigurator));
+      assertThat(ConfiguratorRegistry.getDefaultRegistry().getConfigurators())
+              .containsExactly(noopConfigurator);
+      assertThat(InternalConfiguratorRegistry.getConfiguratorsCallCountBeforeSet()).isEqualTo(1);
     }
   }
 

api/src/test/java/io/grpc/MetadataTest.java

@@ -16,6 +16,7 @@
 
 package io.grpc;
 
+import static com.google.common.truth.Truth.assertThat;
 import static java.nio.charset.StandardCharsets.US_ASCII;
 import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.junit.Assert.assertArrayEquals;
@@ -24,6 +25,7 @@ import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotSame;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertThrows;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
@@ -37,9 +39,7 @@ import java.io.InputStream;
 import java.util.Arrays;
 import java.util.Iterator;
 import java.util.Locale;
-import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
@@ -49,9 +49,6 @@ import org.junit.runners.JUnit4;
 @RunWith(JUnit4.class)
 public class MetadataTest {
 
-  @SuppressWarnings("deprecation") // https://github.com/grpc/grpc-java/issues/7467
-  @Rule public final ExpectedException thrown = ExpectedException.none();
-
   private static final Metadata.BinaryMarshaller<Fish> FISH_MARSHALLER =
       new Metadata.BinaryMarshaller<Fish>() {
         @Override
@@ -65,7 +62,7 @@ public class MetadataTest {
         }
       };
 
-  private static class FishStreamMarsaller implements Metadata.BinaryStreamMarshaller<Fish> {
+  private static class FishStreamMarshaller implements Metadata.BinaryStreamMarshaller<Fish> {
     @Override
     public InputStream toStream(Fish fish) {
       return new ByteArrayInputStream(FISH_MARSHALLER.toBytes(fish));
@@ -82,7 +79,7 @@ public class MetadataTest {
   }
 
   private static final Metadata.BinaryStreamMarshaller<Fish> FISH_STREAM_MARSHALLER =
-      new FishStreamMarsaller();
+      new FishStreamMarshaller();
 
   /** A pattern commonly used to avoid unnecessary serialization of immutable objects. */
   private static final class FakeFishStream extends InputStream {
@@ -121,10 +118,9 @@ public class MetadataTest {
 
   @Test
   public void noPseudoHeaders() {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("Invalid character");
-
-    Metadata.Key.of(":test-bin", FISH_MARSHALLER);
+    IllegalArgumentException e = assertThrows(IllegalArgumentException.class,
+        () -> Metadata.Key.of(":test-bin", FISH_MARSHALLER));
+    assertThat(e).hasMessageThat().isEqualTo("Invalid character ':' in key name ':test-bin'");
   }
 
   @Test
@@ -186,8 +182,7 @@ public class MetadataTest {
     Iterator<Fish> i = metadata.getAll(KEY).iterator();
     assertEquals(lance, i.next());
 
-    thrown.expect(UnsupportedOperationException.class);
-    i.remove();
+    assertThrows(UnsupportedOperationException.class, i::remove);
   }
 
   @Test
@@ -271,17 +266,15 @@ public class MetadataTest {
 
   @Test
   public void shortBinaryKeyName() {
-    thrown.expect(IllegalArgumentException.class);
-
-    Metadata.Key.of("-bin", FISH_MARSHALLER);
+    assertThrows(IllegalArgumentException.class, () -> Metadata.Key.of("-bin", FISH_MARSHALLER));
   }
 
   @Test
   public void invalidSuffixBinaryKeyName() {
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("Binary header is named");
-
-    Metadata.Key.of("nonbinary", FISH_MARSHALLER);
+    IllegalArgumentException e = assertThrows(IllegalArgumentException.class,
+        () -> Metadata.Key.of("nonbinary", FISH_MARSHALLER));
+    assertThat(e).hasMessageThat()
+        .isEqualTo("Binary header is named nonbinary. It must end with -bin");
   }
 
   @Test
@@ -415,7 +408,7 @@ public class MetadataTest {
     h.put(KEY_STREAMED, salmon);
 
     // Get using a different marshaller instance.
-    Fish fish = h.get(copyKey(KEY_STREAMED, new FishStreamMarsaller()));
+    Fish fish = h.get(copyKey(KEY_STREAMED, new FishStreamMarshaller()));
     assertEquals(salmon, fish);
   }
 

api/src/test/java/io/grpc/MethodDescriptorTest.java

@@ -26,9 +26,7 @@ import static org.junit.Assert.assertTrue;
 import io.grpc.MethodDescriptor.Marshaller;
 import io.grpc.MethodDescriptor.MethodType;
 import io.grpc.testing.TestMethodDescriptors;
-import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
@@ -37,10 +35,6 @@ import org.junit.runners.JUnit4;
  */
 @RunWith(JUnit4.class)
 public class MethodDescriptorTest {
-  @SuppressWarnings("deprecation") // https://github.com/grpc/grpc-java/issues/7467
-  @Rule
-  public final ExpectedException thrown = ExpectedException.none();
-
   @Test
   public void createMethodDescriptor() {
     MethodDescriptor<String, String> descriptor = MethodDescriptor.<String, String>newBuilder()

api/src/test/java/io/grpc/NameResolverTest.java

@@ -47,9 +47,13 @@ public class NameResolverTest {
   private static final List<EquivalentAddressGroup> ADDRESSES =
       Collections.singletonList(
           new EquivalentAddressGroup(new FakeSocketAddress("fake-address-1"), Attributes.EMPTY));
-  private static final Attributes.Key<String> YOLO_KEY = Attributes.Key.create("yolo");
-  private static Attributes ATTRIBUTES = Attributes.newBuilder()
-      .set(YOLO_KEY, "To be, or not to be?").build();
+  private static final Attributes.Key<String> YOLO_ATTR_KEY = Attributes.Key.create("yolo");
+  private static Attributes ATTRIBUTES =
+      Attributes.newBuilder().set(YOLO_ATTR_KEY, "To be, or not to be?").build();
+  private static final NameResolver.Args.Key<Integer> FOO_ARG_KEY =
+      NameResolver.Args.Key.create("foo");
+  private static final NameResolver.Args.Key<Integer> BAR_ARG_KEY =
+          NameResolver.Args.Key.create("bar");
   private static ConfigOrError CONFIG = ConfigOrError.fromConfig("foo");
 
   @Rule
@@ -64,6 +68,8 @@ public class NameResolverTest {
   private final ChannelLogger channelLogger = mock(ChannelLogger.class);
   private final Executor executor = Executors.newSingleThreadExecutor();
   private final String overrideAuthority = "grpc.io";
+  private final MetricRecorder metricRecorder = new MetricRecorder() {};
+  private final int customArgValue = 42;
   @Mock NameResolver.Listener mockListener;
 
   @Test
@@ -77,6 +83,9 @@ public class NameResolverTest {
     assertThat(args.getChannelLogger()).isSameInstanceAs(channelLogger);
     assertThat(args.getOffloadExecutor()).isSameInstanceAs(executor);
     assertThat(args.getOverrideAuthority()).isSameInstanceAs(overrideAuthority);
+    assertThat(args.getMetricRecorder()).isSameInstanceAs(metricRecorder);
+    assertThat(args.getArg(FOO_ARG_KEY)).isEqualTo(customArgValue);
+    assertThat(args.getArg(BAR_ARG_KEY)).isNull();
 
     NameResolver.Args args2 = args.toBuilder().build();
     assertThat(args2.getDefaultPort()).isEqualTo(defaultPort);
@@ -87,6 +96,9 @@ public class NameResolverTest {
     assertThat(args2.getChannelLogger()).isSameInstanceAs(channelLogger);
     assertThat(args2.getOffloadExecutor()).isSameInstanceAs(executor);
     assertThat(args2.getOverrideAuthority()).isSameInstanceAs(overrideAuthority);
+    assertThat(args.getMetricRecorder()).isSameInstanceAs(metricRecorder);
+    assertThat(args.getArg(FOO_ARG_KEY)).isEqualTo(customArgValue);
+    assertThat(args.getArg(BAR_ARG_KEY)).isNull();
 
     assertThat(args2).isNotSameInstanceAs(args);
     assertThat(args2).isNotEqualTo(args);
@@ -102,6 +114,8 @@ public class NameResolverTest {
         .setChannelLogger(channelLogger)
         .setOffloadExecutor(executor)
         .setOverrideAuthority(overrideAuthority)
+        .setMetricRecorder(metricRecorder)
+        .setArg(FOO_ARG_KEY, customArgValue)
         .build();
   }
 

api/src/test/java/io/grpc/ServerInterceptorsTest.java

@@ -19,6 +19,7 @@ package io.grpc;
 import static com.google.common.collect.Iterables.getOnlyElement;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertThrows;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.AdditionalAnswers.delegatesTo;
 import static org.mockito.ArgumentMatchers.same;
@@ -40,7 +41,6 @@ import org.junit.After;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 import org.mockito.ArgumentMatchers;
@@ -55,10 +55,6 @@ public class ServerInterceptorsTest {
   @Rule
   public final MockitoRule mocks = MockitoJUnit.rule();
 
-  @SuppressWarnings("deprecation") // https://github.com/grpc/grpc-java/issues/7467
-  @Rule
-  public final ExpectedException thrown = ExpectedException.none();
-
   @Mock
   private Marshaller<String> requestMarshaller;
 
@@ -111,21 +107,21 @@ public class ServerInterceptorsTest {
   public void npeForNullServiceDefinition() {
     ServerServiceDefinition serviceDef = null;
     List<ServerInterceptor> interceptors = Arrays.asList();
-    thrown.expect(NullPointerException.class);
-    ServerInterceptors.intercept(serviceDef, interceptors);
+    assertThrows(NullPointerException.class,
+        () -> ServerInterceptors.intercept(serviceDef, interceptors));
   }
 
   @Test
   public void npeForNullInterceptorList() {
-    thrown.expect(NullPointerException.class);
-    ServerInterceptors.intercept(serviceDefinition, (List<ServerInterceptor>) null);
+    assertThrows(NullPointerException.class,
+        () -> ServerInterceptors.intercept(serviceDefinition, (List<ServerInterceptor>) null));
   }
 
   @Test
   public void npeForNullInterceptor() {
     List<ServerInterceptor> interceptors = Arrays.asList((ServerInterceptor) null);
-    thrown.expect(NullPointerException.class);
-    ServerInterceptors.intercept(serviceDefinition, interceptors);
+    assertThrows(NullPointerException.class,
+        () -> ServerInterceptors.intercept(serviceDefinition, interceptors));
   }
 
   @Test

api/src/test/java/io/grpc/ServerServiceDefinitionTest.java

@@ -18,14 +18,13 @@ package io.grpc;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertThrows;
 import static org.junit.Assert.fail;
 
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashSet;
-import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
@@ -52,9 +51,6 @@ public class ServerServiceDefinitionTest {
         = ServerMethodDefinition.create(method1, methodHandler1);
   private ServerMethodDefinition<String, Integer> methodDef2
         = ServerMethodDefinition.create(method2, methodHandler2);
-  @SuppressWarnings("deprecation") // https://github.com/grpc/grpc-java/issues/7467
-  @Rule
-  public ExpectedException thrown = ExpectedException.none();
 
   @Test
   public void noMethods() {
@@ -91,9 +87,7 @@ public class ServerServiceDefinitionTest {
     ServiceDescriptor sd = new ServiceDescriptor(serviceName, method1);
     ServerServiceDefinition.Builder ssd = ServerServiceDefinition.builder(sd)
         .addMethod(method1, methodHandler1);
-    thrown.expect(IllegalStateException.class);
-    ssd.addMethod(diffMethod1, methodHandler2)
-        .build();
+    assertThrows(IllegalStateException.class, () -> ssd.addMethod(diffMethod1, methodHandler2));
   }
 
   @Test
@@ -101,8 +95,7 @@ public class ServerServiceDefinitionTest {
     ServiceDescriptor sd = new ServiceDescriptor(serviceName);
     ServerServiceDefinition.Builder ssd = ServerServiceDefinition.builder(sd)
         .addMethod(methodDef1);
-    thrown.expect(IllegalStateException.class);
-    ssd.build();
+    assertThrows(IllegalStateException.class, ssd::build);
   }
 
   @Test
@@ -110,16 +103,14 @@ public class ServerServiceDefinitionTest {
     ServiceDescriptor sd = new ServiceDescriptor(serviceName, method1);
     ServerServiceDefinition.Builder ssd = ServerServiceDefinition.builder(sd)
         .addMethod(diffMethod1, methodHandler1);
-    thrown.expect(IllegalStateException.class);
-    ssd.build();
+    assertThrows(IllegalStateException.class, ssd::build);
   }
 
   @Test
   public void buildMisaligned_missingMethod() {
     ServiceDescriptor sd = new ServiceDescriptor(serviceName, method1);
     ServerServiceDefinition.Builder ssd = ServerServiceDefinition.builder(sd);
-    thrown.expect(IllegalStateException.class);
-    ssd.build();
+    assertThrows(IllegalStateException.class, ssd::build);
   }
 
   @Test

api/src/test/java/io/grpc/ServiceDescriptorTest.java

@@ -16,17 +16,18 @@
 
 package io.grpc;
 
+import static com.google.common.truth.Truth.assertThat;
+import static org.junit.Assert.assertThrows;
 import static org.junit.Assert.assertTrue;
 
+import com.google.common.truth.StringSubject;
 import io.grpc.MethodDescriptor.MethodType;
 import io.grpc.testing.TestMethodDescriptors;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
-import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
@@ -36,32 +37,27 @@ import org.junit.runners.JUnit4;
 @RunWith(JUnit4.class)
 public class ServiceDescriptorTest {
 
-  @SuppressWarnings("deprecation") // https://github.com/grpc/grpc-java/issues/7467
-  @Rule
-  public final ExpectedException thrown = ExpectedException.none();
-
   @Test
   public void failsOnNullName() {
-    thrown.expect(NullPointerException.class);
-    thrown.expectMessage("name");
-
-    new ServiceDescriptor(null, Collections.<MethodDescriptor<?, ?>>emptyList());
+    List<MethodDescriptor<?, ?>> methods = Collections.emptyList();
+    NullPointerException e = assertThrows(NullPointerException.class,
+        () -> new ServiceDescriptor(null, methods));
+    assertThat(e).hasMessageThat().isEqualTo("name");
   }
 
   @Test
   public void failsOnNullMethods() {
-    thrown.expect(NullPointerException.class);
-    thrown.expectMessage("methods");
-
-    new ServiceDescriptor("name", (Collection<MethodDescriptor<?, ?>>) null);
+    NullPointerException e = assertThrows(NullPointerException.class,
+        () -> new ServiceDescriptor("name", (Collection<MethodDescriptor<?, ?>>) null));
+    assertThat(e).hasMessageThat().isEqualTo("methods");
   }
 
   @Test
   public void failsOnNullMethod() {
-    thrown.expect(NullPointerException.class);
-    thrown.expectMessage("method");
-
-    new ServiceDescriptor("name", Collections.<MethodDescriptor<?, ?>>singletonList(null));
+    List<MethodDescriptor<?, ?>> methods = Collections.singletonList(null);
+    NullPointerException e = assertThrows(NullPointerException.class,
+        () -> new ServiceDescriptor("name", methods));
+    assertThat(e).hasMessageThat().isEqualTo("method");
   }
 
   @Test
@@ -69,15 +65,17 @@ public class ServiceDescriptorTest {
     List<MethodDescriptor<?, ?>> descriptors = Collections.<MethodDescriptor<?, ?>>singletonList(
         MethodDescriptor.<Void, Void>newBuilder()
           .setType(MethodType.UNARY)
-          .setFullMethodName(MethodDescriptor.generateFullMethodName("wrongservice", "method"))
+          .setFullMethodName(MethodDescriptor.generateFullMethodName("wrongService", "method"))
           .setRequestMarshaller(TestMethodDescriptors.voidMarshaller())
           .setResponseMarshaller(TestMethodDescriptors.voidMarshaller())
           .build());
 
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("service names");
-
-    new ServiceDescriptor("name", descriptors);
+    IllegalArgumentException e = assertThrows(IllegalArgumentException.class,
+        () -> new ServiceDescriptor("fooService", descriptors));
+    StringSubject error = assertThat(e).hasMessageThat();
+    error.contains("service names");
+    error.contains("fooService");
+    error.contains("wrongService");
   }
 
   @Test
@@ -96,10 +94,9 @@ public class ServiceDescriptorTest {
           .setResponseMarshaller(TestMethodDescriptors.voidMarshaller())
           .build());
 
-    thrown.expect(IllegalArgumentException.class);
-    thrown.expectMessage("duplicate");
-
-    new ServiceDescriptor("name", descriptors);
+    IllegalArgumentException e = assertThrows(IllegalArgumentException.class,
+        () -> new ServiceDescriptor("name", descriptors));
+    assertThat(e).hasMessageThat().isEqualTo("duplicate name name/method");
   }
 
   @Test

api/src/test/java/io/grpc/StatusExceptionTest.java

@@ -28,14 +28,6 @@ import org.junit.runners.JUnit4;
 @RunWith(JUnit4.class)
 public class StatusExceptionTest {
 
-  @Test
-  public void internalCtorRemovesStack() {
-    StackTraceElement[] trace =
-        new StatusException(Status.CANCELLED, null, false) {}.getStackTrace();
-
-    assertThat(trace).isEmpty();
-  }
-
   @Test
   public void normalCtorKeepsStack() {
     StackTraceElement[] trace =

api/src/test/java/io/grpc/StatusRuntimeExceptionTest.java

@@ -31,7 +31,7 @@ public class StatusRuntimeExceptionTest {
   @Test
   public void internalCtorRemovesStack() {
     StackTraceElement[] trace =
-        new StatusRuntimeException(Status.CANCELLED, null, false) {}.getStackTrace();
+        new InternalStatusRuntimeException(Status.CANCELLED, null) {}.getStackTrace();
 
     assertThat(trace).isEmpty();
   }

api/src/test/java/io/grpc/SynchronizationContextTest.java

@@ -27,6 +27,7 @@ import static org.mockito.Mockito.verify;
 
 import com.google.common.util.concurrent.testing.TestingExecutors;
 import io.grpc.SynchronizationContext.ScheduledHandle;
+import java.time.Duration;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.LinkedBlockingQueue;
@@ -72,7 +73,7 @@ public class SynchronizationContextTest {
 
   @Mock
   private Runnable task3;
-  
+
   @After public void tearDown() {
     assertThat(uncaughtErrors).isEmpty();
   }
@@ -246,6 +247,43 @@ public class SynchronizationContextTest {
     verify(task1).run();
   }
 
+  @Test
+  @IgnoreJRERequirement
+  public void scheduleDuration() {
+    MockScheduledExecutorService executorService = new MockScheduledExecutorService();
+    ScheduledHandle handle =
+        syncContext.schedule(task1, Duration.ofSeconds(10), executorService);
+
+    assertThat(executorService.delay)
+        .isEqualTo(executorService.unit.convert(10, TimeUnit.SECONDS));
+    assertThat(handle.isPending()).isTrue();
+    verify(task1, never()).run();
+
+    executorService.command.run();
+
+    assertThat(handle.isPending()).isFalse();
+    verify(task1).run();
+  }
+
+  @Test
+  @IgnoreJRERequirement
+  public void scheduleWithFixedDelayDuration() {
+    MockScheduledExecutorService executorService = new MockScheduledExecutorService();
+    ScheduledHandle handle =
+        syncContext.scheduleWithFixedDelay(task1, Duration.ofSeconds(10),
+            Duration.ofSeconds(10), executorService);
+
+    assertThat(executorService.delay)
+        .isEqualTo(executorService.unit.convert(10, TimeUnit.SECONDS));
+    assertThat(handle.isPending()).isTrue();
+    verify(task1, never()).run();
+
+    executorService.command.run();
+
+    assertThat(handle.isPending()).isFalse();
+    verify(task1).run();
+  }
+
   @Test
   public void scheduleDueImmediately() {
     MockScheduledExecutorService executorService = new MockScheduledExecutorService();
@@ -357,5 +395,13 @@ public class SynchronizationContextTest {
       this.unit = unit;
       return future = super.schedule(command, delay, unit);
     }
+
+    @Override public ScheduledFuture<?> scheduleWithFixedDelay(Runnable command, long intialDelay,
+        long delay, TimeUnit unit) {
+      this.command = command;
+      this.delay = delay;
+      this.unit = unit;
+      return future = super.scheduleWithFixedDelay(command, intialDelay, delay, unit);
+    }
   }
 }

api/src/test/java/io/grpc/TimeUtilsTest.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2024 The gRPC Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.grpc;
+
+import static org.junit.Assert.assertEquals;
+
+import java.time.Duration;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Unit tests for {@link TimeUtils}. */
+@RunWith(JUnit4.class)
+@IgnoreJRERequirement
+public class TimeUtilsTest {
+
+  @Test
+  public void testConvertNormalDuration() {
+    Duration duration = Duration.ofSeconds(10);
+    long expected = 10 * 1_000_000_000L;
+
+    assertEquals(expected, TimeUtils.convertToNanos(duration));
+  }
+
+  @Test
+  public void testConvertNegativeDuration() {
+    Duration duration = Duration.ofSeconds(-3);
+    long expected = -3 * 1_000_000_000L;
+
+    assertEquals(expected, TimeUtils.convertToNanos(duration));
+  }
+
+  @Test
+  public void testConvertTooLargeDuration() {
+    Duration duration = Duration.ofSeconds(Long.MAX_VALUE / 1_000_000_000L + 1);
+
+    assertEquals(Long.MAX_VALUE, TimeUtils.convertToNanos(duration));
+  }
+
+  @Test
+  public void testConvertTooLargeNegativeDuration() {
+    Duration duration = Duration.ofSeconds(Long.MIN_VALUE / 1_000_000_000L - 1);
+
+    assertEquals(Long.MIN_VALUE, TimeUtils.convertToNanos(duration));
+  }
+}

api/src/testFixtures/java/io/grpc/StatusMatcher.java

@@ -0,0 +1,118 @@
+/*
+ * Copyright 2025 The gRPC Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.grpc;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.base.Preconditions.checkState;
+
+import org.mockito.ArgumentMatcher;
+
+/**
+ * Mockito matcher for {@link Status}.
+ */
+public final class StatusMatcher implements ArgumentMatcher<Status> {
+  public static StatusMatcher statusHasCode(ArgumentMatcher<Status.Code> codeMatcher) {
+    return new StatusMatcher(codeMatcher, null);
+  }
+
+  public static StatusMatcher statusHasCode(Status.Code code) {
+    return statusHasCode(new EqualsMatcher<>(code));
+  }
+
+  private final ArgumentMatcher<Status.Code> codeMatcher;
+  private final ArgumentMatcher<String> descriptionMatcher;
+
+  private StatusMatcher(
+      ArgumentMatcher<Status.Code> codeMatcher,
+      ArgumentMatcher<String> descriptionMatcher) {
+    this.codeMatcher = checkNotNull(codeMatcher, "codeMatcher");
+    this.descriptionMatcher = descriptionMatcher;
+  }
+
+  public StatusMatcher andDescription(ArgumentMatcher<String> descriptionMatcher) {
+    checkState(this.descriptionMatcher == null, "Already has a description matcher");
+    return new StatusMatcher(codeMatcher, descriptionMatcher);
+  }
+
+  public StatusMatcher andDescription(String description) {
+    return andDescription(new EqualsMatcher<>(description));
+  }
+
+  public StatusMatcher andDescriptionContains(String substring) {
+    return andDescription(new StringContainsMatcher(substring));
+  }
+
+  @Override
+  public boolean matches(Status status) {
+    return status != null
+        && codeMatcher.matches(status.getCode())
+        && (descriptionMatcher == null || descriptionMatcher.matches(status.getDescription()));
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("{code=");
+    sb.append(codeMatcher);
+    if (descriptionMatcher != null) {
+      sb.append(", description=");
+      sb.append(descriptionMatcher);
+    }
+    sb.append("}");
+    return sb.toString();
+  }
+
+  // Use instead of lambda for better error message.
+  static final class EqualsMatcher<T> implements ArgumentMatcher<T> {
+    private final T obj;
+
+    EqualsMatcher(T obj) {
+      this.obj = checkNotNull(obj, "obj");
+    }
+
+    @Override
+    public boolean matches(Object other) {
+      return obj.equals(other);
+    }
+
+    @Override
+    public String toString() {
+      return obj.toString();
+    }
+  }
+
+  static final class StringContainsMatcher implements ArgumentMatcher<String> {
+    private final String needle;
+
+    StringContainsMatcher(String needle) {
+      this.needle = checkNotNull(needle, "needle");
+    }
+
+    @Override
+    public boolean matches(String haystack) {
+      if (haystack == null) {
+        return false;
+      }
+      return haystack.contains(needle);
+    }
+
+    @Override
+    public String toString() {
+      return "contains " + needle;
+    }
+  }
+}

api/src/testFixtures/java/io/grpc/StatusOrMatcher.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2025 The gRPC Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.grpc;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import org.mockito.ArgumentMatcher;
+
+/**
+ * Mockito matcher for {@link StatusOr}.
+ */
+public final class StatusOrMatcher<T> implements ArgumentMatcher<StatusOr<T>> {
+  public static <T> StatusOrMatcher<T> hasValue(ArgumentMatcher<T> valueMatcher) {
+    return new StatusOrMatcher<T>(checkNotNull(valueMatcher, "valueMatcher"), null);
+  }
+
+  public static <T> StatusOrMatcher<T> hasStatus(ArgumentMatcher<Status> statusMatcher) {
+    return new StatusOrMatcher<T>(null, checkNotNull(statusMatcher, "statusMatcher"));
+  }
+
+  private final ArgumentMatcher<T> valueMatcher;
+  private final ArgumentMatcher<Status> statusMatcher;
+
+  private StatusOrMatcher(ArgumentMatcher<T> valueMatcher, ArgumentMatcher<Status> statusMatcher) {
+    this.valueMatcher = valueMatcher;
+    this.statusMatcher = statusMatcher;
+  }
+
+  @Override
+  public boolean matches(StatusOr<T> statusOr) {
+    if (statusOr == null) {
+      return false;
+    }
+    if (statusOr.hasValue() != (valueMatcher != null)) {
+      return false;
+    }
+    if (valueMatcher != null) {
+      return valueMatcher.matches(statusOr.getValue());
+    } else {
+      return statusMatcher.matches(statusOr.getStatus());
+    }
+  }
+
+  @Override
+  public String toString() {
+    if (valueMatcher != null) {
+      return "{value=" + valueMatcher + "}";
+    } else {
+      return "{status=" + statusMatcher + "}";
+    }
+  }
+}

api/src/testFixtures/java/io/grpc/testing/DeadlineSubject.java

@@ -24,9 +24,9 @@ import static java.util.concurrent.TimeUnit.SECONDS;
 import com.google.common.truth.ComparableSubject;
 import com.google.common.truth.FailureMetadata;
 import com.google.common.truth.Subject;
+import com.google.errorprone.annotations.CheckReturnValue;
 import io.grpc.Deadline;
 import java.util.concurrent.TimeUnit;
-import javax.annotation.CheckReturnValue;
 import javax.annotation.Nullable;
 
 /** Propositions for {@link Deadline} subjects. */
@@ -67,7 +67,7 @@ public final class DeadlineSubject extends ComparableSubject {
         if (Math.abs(actualNanos - expectedNanos) > deltaNanos) {
           failWithoutActual(
               fact("expected", expectedNanos / NANOSECONDS_IN_A_SECOND),
-              fact("but was", expectedNanos  / NANOSECONDS_IN_A_SECOND),
+              fact("but was", actualNanos  / NANOSECONDS_IN_A_SECOND),
               fact("outside tolerance in seconds",  deltaNanos  / NANOSECONDS_IN_A_SECOND));
         }
       }

auth/build.gradle

@@ -22,6 +22,14 @@ dependencies {
             project(':grpc-core'),
             project(":grpc-context"), // Override google-auth dependency with our newer version
             libraries.google.auth.oauth2Http
-    signature libraries.signature.java
-    signature libraries.signature.android
+    signature (libraries.signature.java) {
+        artifact {
+            extension = "signature"
+        }
+    }
+    signature (libraries.signature.android) {
+        artifact {
+            extension = "signature"
+        }
+    }
 }

auth/src/test/java/io/grpc/auth/GoogleAuthLibraryCallCredentialsTest.java

@@ -50,10 +50,12 @@ import io.grpc.SecurityLevel;
 import io.grpc.Status;
 import io.grpc.internal.JsonParser;
 import io.grpc.testing.TestMethodDescriptors;
+import io.grpc.testing.TlsTesting;
+import io.grpc.util.CertificateUtils;
 import java.io.IOException;
+import java.io.InputStream;
 import java.net.URI;
-import java.security.KeyPair;
-import java.security.KeyPairGenerator;
+import java.security.PrivateKey;
 import java.util.ArrayList;
 import java.util.Date;
 import java.util.List;
@@ -342,7 +344,10 @@ public class GoogleAuthLibraryCallCredentialsTest {
 
   @Test
   public void serviceAccountToJwt() throws Exception {
-    KeyPair pair = KeyPairGenerator.getInstance("RSA").generateKeyPair();
+    PrivateKey privateKey;
+    try (InputStream server1Key = TlsTesting.loadCert("server1.key")) {
+      privateKey = CertificateUtils.getPrivateKey(server1Key);
+    }
 
     HttpTransportFactory factory = Mockito.mock(HttpTransportFactory.class);
     Mockito.when(factory.create()).thenThrow(new AssertionError());
@@ -350,7 +355,7 @@ public class GoogleAuthLibraryCallCredentialsTest {
     ServiceAccountCredentials credentials =
         ServiceAccountCredentials.newBuilder()
             .setClientEmail("test-email@example.com")
-            .setPrivateKey(pair.getPrivate())
+            .setPrivateKey(privateKey)
             .setPrivateKeyId("test-private-key-id")
             .setHttpTransportFactory(factory)
             .build();
@@ -390,13 +395,16 @@ public class GoogleAuthLibraryCallCredentialsTest {
 
   @Test
   public void jwtAccessCredentialsInRequestMetadata() throws Exception {
-    KeyPair pair = KeyPairGenerator.getInstance("RSA").generateKeyPair();
+    PrivateKey privateKey;
+    try (InputStream server1Key = TlsTesting.loadCert("server1.key")) {
+      privateKey = CertificateUtils.getPrivateKey(server1Key);
+    }
 
     ServiceAccountCredentials credentials =
         ServiceAccountCredentials.newBuilder()
             .setClientId("test-client")
             .setClientEmail("test-email@example.com")
-            .setPrivateKey(pair.getPrivate())
+            .setPrivateKey(privateKey)
             .setPrivateKeyId("test-private-key-id")
             .setQuotaProjectId("test-quota-project-id")
             .build();

authz/build.gradle

@@ -2,8 +2,8 @@ plugins {
     id "java-library"
     id "maven-publish"
 
-    id "com.github.johnrengelman.shadow"
     id "com.google.protobuf"
+    id "com.gradleup.shadow"
     id "ru.vyarus.animalsniffer"
 }
 
@@ -26,7 +26,11 @@ dependencies {
     shadow configurations.implementation.getDependencies().minus([xdsDependency])
     shadow project(path: ':grpc-xds', configuration: 'shadow')
 
-    signature libraries.signature.java
+    signature (libraries.signature.java) {
+        artifact {
+            extension = "signature"
+        }
+    }
 }
 
 tasks.named("jar").configure {

benchmarks/build.gradle

@@ -43,7 +43,11 @@ dependencies {
     testImplementation libraries.junit,
             libraries.mockito.core
 
-    signature libraries.signature.java
+    signature (libraries.signature.java) {
+        artifact {
+            extension = "signature"
+        }
+    }
 }
 
 import net.ltgt.gradle.errorprone.CheckSeverity

benchmarks/src/generated/main/grpc/io/grpc/benchmarks/proto/BenchmarkServiceGrpc.java

@@ -4,9 +4,6 @@ import static io.grpc.MethodDescriptor.generateFullMethodName;
 
 /**
  */
-@javax.annotation.Generated(
-    value = "by gRPC proto compiler",
-    comments = "Source: grpc/testing/services.proto")
 @io.grpc.stub.annotations.GrpcGenerated
 public final class BenchmarkServiceGrpc {
 
@@ -184,6 +181,21 @@ public final class BenchmarkServiceGrpc {
     return BenchmarkServiceStub.newStub(factory, channel);
   }
 
+  /**
+   * Creates a new blocking-style stub that supports all types of calls on the service
+   */
+  public static BenchmarkServiceBlockingV2Stub newBlockingV2Stub(
+      io.grpc.Channel channel) {
+    io.grpc.stub.AbstractStub.StubFactory<BenchmarkServiceBlockingV2Stub> factory =
+      new io.grpc.stub.AbstractStub.StubFactory<BenchmarkServiceBlockingV2Stub>() {
+        @java.lang.Override
+        public BenchmarkServiceBlockingV2Stub newStub(io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+          return new BenchmarkServiceBlockingV2Stub(channel, callOptions);
+        }
+      };
+    return BenchmarkServiceBlockingV2Stub.newStub(factory, channel);
+  }
+
   /**
    * Creates a new blocking-style stub that supports unary and streaming output calls on the service
    */
@@ -367,6 +379,87 @@ public final class BenchmarkServiceGrpc {
   /**
    * A stub to allow clients to do synchronous rpc calls to service BenchmarkService.
    */
+  public static final class BenchmarkServiceBlockingV2Stub
+      extends io.grpc.stub.AbstractBlockingStub<BenchmarkServiceBlockingV2Stub> {
+    private BenchmarkServiceBlockingV2Stub(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      super(channel, callOptions);
+    }
+
+    @java.lang.Override
+    protected BenchmarkServiceBlockingV2Stub build(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      return new BenchmarkServiceBlockingV2Stub(channel, callOptions);
+    }
+
+    /**
+     * <pre>
+     * One request followed by one response.
+     * The server returns the client payload as-is.
+     * </pre>
+     */
+    public io.grpc.benchmarks.proto.Messages.SimpleResponse unaryCall(io.grpc.benchmarks.proto.Messages.SimpleRequest request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getUnaryCallMethod(), getCallOptions(), request);
+    }
+
+    /**
+     * <pre>
+     * Repeated sequence of one request followed by one response.
+     * Should be called streaming ping-pong
+     * The server returns the client payload as-is on each response
+     * </pre>
+     */
+    @io.grpc.ExperimentalApi("https://github.com/grpc/grpc-java/issues/10918")
+    public io.grpc.stub.BlockingClientCall<io.grpc.benchmarks.proto.Messages.SimpleRequest, io.grpc.benchmarks.proto.Messages.SimpleResponse>
+        streamingCall() {
+      return io.grpc.stub.ClientCalls.blockingBidiStreamingCall(
+          getChannel(), getStreamingCallMethod(), getCallOptions());
+    }
+
+    /**
+     * <pre>
+     * Single-sided unbounded streaming from client to server
+     * The server returns the client payload as-is once the client does WritesDone
+     * </pre>
+     */
+    @io.grpc.ExperimentalApi("https://github.com/grpc/grpc-java/issues/10918")
+    public io.grpc.stub.BlockingClientCall<io.grpc.benchmarks.proto.Messages.SimpleRequest, io.grpc.benchmarks.proto.Messages.SimpleResponse>
+        streamingFromClient() {
+      return io.grpc.stub.ClientCalls.blockingClientStreamingCall(
+          getChannel(), getStreamingFromClientMethod(), getCallOptions());
+    }
+
+    /**
+     * <pre>
+     * Single-sided unbounded streaming from server to client
+     * The server repeatedly returns the client payload as-is
+     * </pre>
+     */
+    @io.grpc.ExperimentalApi("https://github.com/grpc/grpc-java/issues/10918")
+    public io.grpc.stub.BlockingClientCall<?, io.grpc.benchmarks.proto.Messages.SimpleResponse>
+        streamingFromServer(io.grpc.benchmarks.proto.Messages.SimpleRequest request) {
+      return io.grpc.stub.ClientCalls.blockingV2ServerStreamingCall(
+          getChannel(), getStreamingFromServerMethod(), getCallOptions(), request);
+    }
+
+    /**
+     * <pre>
+     * Two-sided unbounded streaming between server to client
+     * Both sides send the content of their own choice to the other
+     * </pre>
+     */
+    @io.grpc.ExperimentalApi("https://github.com/grpc/grpc-java/issues/10918")
+    public io.grpc.stub.BlockingClientCall<io.grpc.benchmarks.proto.Messages.SimpleRequest, io.grpc.benchmarks.proto.Messages.SimpleResponse>
+        streamingBothWays() {
+      return io.grpc.stub.ClientCalls.blockingBidiStreamingCall(
+          getChannel(), getStreamingBothWaysMethod(), getCallOptions());
+    }
+  }
+
+  /**
+   * A stub to allow clients to do limited synchronous rpc calls to service BenchmarkService.
+   */
   public static final class BenchmarkServiceBlockingStub
       extends io.grpc.stub.AbstractBlockingStub<BenchmarkServiceBlockingStub> {
     private BenchmarkServiceBlockingStub(

benchmarks/src/generated/main/grpc/io/grpc/benchmarks/proto/ReportQpsScenarioServiceGrpc.java

@@ -4,9 +4,6 @@ import static io.grpc.MethodDescriptor.generateFullMethodName;
 
 /**
  */
-@javax.annotation.Generated(
-    value = "by gRPC proto compiler",
-    comments = "Source: grpc/testing/services.proto")
 @io.grpc.stub.annotations.GrpcGenerated
 public final class ReportQpsScenarioServiceGrpc {
 
@@ -60,6 +57,21 @@ public final class ReportQpsScenarioServiceGrpc {
     return ReportQpsScenarioServiceStub.newStub(factory, channel);
   }
 
+  /**
+   * Creates a new blocking-style stub that supports all types of calls on the service
+   */
+  public static ReportQpsScenarioServiceBlockingV2Stub newBlockingV2Stub(
+      io.grpc.Channel channel) {
+    io.grpc.stub.AbstractStub.StubFactory<ReportQpsScenarioServiceBlockingV2Stub> factory =
+      new io.grpc.stub.AbstractStub.StubFactory<ReportQpsScenarioServiceBlockingV2Stub>() {
+        @java.lang.Override
+        public ReportQpsScenarioServiceBlockingV2Stub newStub(io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+          return new ReportQpsScenarioServiceBlockingV2Stub(channel, callOptions);
+        }
+      };
+    return ReportQpsScenarioServiceBlockingV2Stub.newStub(factory, channel);
+  }
+
   /**
    * Creates a new blocking-style stub that supports unary and streaming output calls on the service
    */
@@ -147,6 +159,33 @@ public final class ReportQpsScenarioServiceGrpc {
   /**
    * A stub to allow clients to do synchronous rpc calls to service ReportQpsScenarioService.
    */
+  public static final class ReportQpsScenarioServiceBlockingV2Stub
+      extends io.grpc.stub.AbstractBlockingStub<ReportQpsScenarioServiceBlockingV2Stub> {
+    private ReportQpsScenarioServiceBlockingV2Stub(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      super(channel, callOptions);
+    }
+
+    @java.lang.Override
+    protected ReportQpsScenarioServiceBlockingV2Stub build(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      return new ReportQpsScenarioServiceBlockingV2Stub(channel, callOptions);
+    }
+
+    /**
+     * <pre>
+     * Report results of a QPS test benchmark scenario.
+     * </pre>
+     */
+    public io.grpc.benchmarks.proto.Control.Void reportScenario(io.grpc.benchmarks.proto.Control.ScenarioResult request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getReportScenarioMethod(), getCallOptions(), request);
+    }
+  }
+
+  /**
+   * A stub to allow clients to do limited synchronous rpc calls to service ReportQpsScenarioService.
+   */
   public static final class ReportQpsScenarioServiceBlockingStub
       extends io.grpc.stub.AbstractBlockingStub<ReportQpsScenarioServiceBlockingStub> {
     private ReportQpsScenarioServiceBlockingStub(

benchmarks/src/generated/main/grpc/io/grpc/benchmarks/proto/WorkerServiceGrpc.java

@@ -4,9 +4,6 @@ import static io.grpc.MethodDescriptor.generateFullMethodName;
 
 /**
  */
-@javax.annotation.Generated(
-    value = "by gRPC proto compiler",
-    comments = "Source: grpc/testing/services.proto")
 @io.grpc.stub.annotations.GrpcGenerated
 public final class WorkerServiceGrpc {
 
@@ -153,6 +150,21 @@ public final class WorkerServiceGrpc {
     return WorkerServiceStub.newStub(factory, channel);
   }
 
+  /**
+   * Creates a new blocking-style stub that supports all types of calls on the service
+   */
+  public static WorkerServiceBlockingV2Stub newBlockingV2Stub(
+      io.grpc.Channel channel) {
+    io.grpc.stub.AbstractStub.StubFactory<WorkerServiceBlockingV2Stub> factory =
+      new io.grpc.stub.AbstractStub.StubFactory<WorkerServiceBlockingV2Stub>() {
+        @java.lang.Override
+        public WorkerServiceBlockingV2Stub newStub(io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+          return new WorkerServiceBlockingV2Stub(channel, callOptions);
+        }
+      };
+    return WorkerServiceBlockingV2Stub.newStub(factory, channel);
+  }
+
   /**
    * Creates a new blocking-style stub that supports unary and streaming output calls on the service
    */
@@ -323,6 +335,77 @@ public final class WorkerServiceGrpc {
   /**
    * A stub to allow clients to do synchronous rpc calls to service WorkerService.
    */
+  public static final class WorkerServiceBlockingV2Stub
+      extends io.grpc.stub.AbstractBlockingStub<WorkerServiceBlockingV2Stub> {
+    private WorkerServiceBlockingV2Stub(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      super(channel, callOptions);
+    }
+
+    @java.lang.Override
+    protected WorkerServiceBlockingV2Stub build(
+        io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
+      return new WorkerServiceBlockingV2Stub(channel, callOptions);
+    }
+
+    /**
+     * <pre>
+     * Start server with specified workload.
+     * First request sent specifies the ServerConfig followed by ServerStatus
+     * response. After that, a "Mark" can be sent anytime to request the latest
+     * stats. Closing the stream will initiate shutdown of the test server
+     * and once the shutdown has finished, the OK status is sent to terminate
+     * this RPC.
+     * </pre>
+     */
+    @io.grpc.ExperimentalApi("https://github.com/grpc/grpc-java/issues/10918")
+    public io.grpc.stub.BlockingClientCall<io.grpc.benchmarks.proto.Control.ServerArgs, io.grpc.benchmarks.proto.Control.ServerStatus>
+        runServer() {
+      return io.grpc.stub.ClientCalls.blockingBidiStreamingCall(
+          getChannel(), getRunServerMethod(), getCallOptions());
+    }
+
+    /**
+     * <pre>
+     * Start client with specified workload.
+     * First request sent specifies the ClientConfig followed by ClientStatus
+     * response. After that, a "Mark" can be sent anytime to request the latest
+     * stats. Closing the stream will initiate shutdown of the test client
+     * and once the shutdown has finished, the OK status is sent to terminate
+     * this RPC.
+     * </pre>
+     */
+    @io.grpc.ExperimentalApi("https://github.com/grpc/grpc-java/issues/10918")
+    public io.grpc.stub.BlockingClientCall<io.grpc.benchmarks.proto.Control.ClientArgs, io.grpc.benchmarks.proto.Control.ClientStatus>
+        runClient() {
+      return io.grpc.stub.ClientCalls.blockingBidiStreamingCall(
+          getChannel(), getRunClientMethod(), getCallOptions());
+    }
+
+    /**
+     * <pre>
+     * Just return the core count - unary call
+     * </pre>
+     */
+    public io.grpc.benchmarks.proto.Control.CoreResponse coreCount(io.grpc.benchmarks.proto.Control.CoreRequest request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getCoreCountMethod(), getCallOptions(), request);
+    }
+
+    /**
+     * <pre>
+     * Quit this worker
+     * </pre>
+     */
+    public io.grpc.benchmarks.proto.Control.Void quitWorker(io.grpc.benchmarks.proto.Control.Void request) throws io.grpc.StatusException {
+      return io.grpc.stub.ClientCalls.blockingV2UnaryCall(
+          getChannel(), getQuitWorkerMethod(), getCallOptions(), request);
+    }
+  }
+
+  /**
+   * A stub to allow clients to do limited synchronous rpc calls to service WorkerService.
+   */
   public static final class WorkerServiceBlockingStub
       extends io.grpc.stub.AbstractBlockingStub<WorkerServiceBlockingStub> {
     private WorkerServiceBlockingStub(

binder/build.gradle

@@ -6,33 +6,32 @@ plugins {
 description = 'gRPC BinderChannel'
 
 android {
-    namespace 'io.grpc.binder'
+    namespace = 'io.grpc.binder'
     compileSdkVersion 34
     compileOptions {
         sourceCompatibility 1.8
         targetCompatibility 1.8
     }
     defaultConfig {
-        minSdkVersion 21
+        minSdkVersion 22
         targetSdkVersion 33
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
-        multiDexEnabled true
+        multiDexEnabled = true
     }
-    lintOptions { abortOnError false }
+    lintOptions { abortOnError = false }
     publishing {
         singleVariant('release') {
             withSourcesJar()
             withJavadocJar()
         }
     }
-    testFixtures { enable true }
+    testFixtures { enable = true }
 }
 
 repositories {
     google()
-    mavenCentral()
 }
 
 dependencies {
@@ -73,6 +72,7 @@ dependencies {
     androidTestImplementation testFixtures(project(':grpc-core'))
 
     testFixturesImplementation libraries.guava.testlib
+    testFixturesImplementation testFixtures(project(':grpc-core'))
 }
 
 import net.ltgt.gradle.errorprone.CheckSeverity

binder/src/androidTest/AndroidManifest.xml

@@ -11,11 +11,13 @@
     <service android:name="io.grpc.binder.HostServices$HostService1" android:exported="false">
       <intent-filter>
         <action android:name="action1"/>
+        <data android:scheme="scheme" android:host="authority" android:path="/path"/>
       </intent-filter>
     </service>
     <service android:name="io.grpc.binder.HostServices$HostService2" android:exported="false">
       <intent-filter>
         <action android:name="action2"/>
+        <data android:scheme="scheme" android:host="authority" android:path="/path"/>
       </intent-filter>
     </service>
   </application>

binder/src/androidTest/java/io/grpc/binder/BinderChannelSmokeTest.java

@@ -23,6 +23,7 @@ import static java.util.concurrent.TimeUnit.SECONDS;
 
 import android.content.Context;
 import android.content.Intent;
+import android.net.Uri;
 import android.os.Parcel;
 import android.os.Parcelable;
 import androidx.test.core.app.ApplicationProvider;
@@ -39,7 +40,6 @@ import io.grpc.ForwardingServerCall.SimpleForwardingServerCall;
 import io.grpc.ManagedChannel;
 import io.grpc.Metadata;
 import io.grpc.MethodDescriptor;
-import io.grpc.NameResolverRegistry;
 import io.grpc.ServerCall;
 import io.grpc.ServerCall.Listener;
 import io.grpc.ServerCallHandler;
@@ -49,7 +49,6 @@ import io.grpc.ServerServiceDefinition;
 import io.grpc.Status.Code;
 import io.grpc.StatusRuntimeException;
 import io.grpc.internal.GrpcUtil;
-import io.grpc.internal.testing.FakeNameResolverProvider;
 import io.grpc.stub.ClientCalls;
 import io.grpc.stub.MetadataUtils;
 import io.grpc.stub.ServerCalls;
@@ -77,7 +76,6 @@ public final class BinderChannelSmokeTest {
 
   private static final int SLIGHTLY_MORE_THAN_ONE_BLOCK = 16 * 1024 + 100;
   private static final String MSG = "Some text which will be repeated many many times";
-  private static final String SERVER_TARGET_URI = "fake://server";
   private static final Metadata.Key<PoisonParcelable> POISON_KEY =
       ParcelableUtils.metadataKey("poison-bin", PoisonParcelable.CREATOR);
 
@@ -99,7 +97,6 @@ public final class BinderChannelSmokeTest {
           .setType(MethodDescriptor.MethodType.BIDI_STREAMING)
           .build();
 
-  FakeNameResolverProvider fakeNameResolverProvider;
   ManagedChannel channel;
   AtomicReference<Metadata> headersCapture = new AtomicReference<>();
   AtomicReference<PeerUid> clientUidCapture = new AtomicReference<>();
@@ -138,8 +135,6 @@ public final class BinderChannelSmokeTest {
             PeerUids.newPeerIdentifyingServerInterceptor());
 
     AndroidComponentAddress serverAddress = HostServices.allocateService(appContext);
-    fakeNameResolverProvider = new FakeNameResolverProvider(SERVER_TARGET_URI, serverAddress);
-    NameResolverRegistry.getDefaultRegistry().register(fakeNameResolverProvider);
     HostServices.configureService(
         serverAddress,
         HostServices.serviceParamsBuilder()
@@ -166,7 +161,6 @@ public final class BinderChannelSmokeTest {
   @After
   public void tearDown() throws Exception {
     channel.shutdownNow();
-    NameResolverRegistry.getDefaultRegistry().deregister(fakeNameResolverProvider);
     HostServices.awaitServiceShutdown();
   }
 
@@ -235,7 +229,11 @@ public final class BinderChannelSmokeTest {
 
   @Test
   public void testConnectViaTargetUri() throws Exception {
-    channel = BinderChannelBuilder.forTarget(SERVER_TARGET_URI, appContext).build();
+    // Compare with the <intent-filter> mapping in AndroidManifest.xml.
+    channel =
+        BinderChannelBuilder.forTarget(
+                "intent://authority/path#Intent;action=action1;scheme=scheme;end;", appContext)
+            .build();
     assertThat(doCall("Hello").get()).isEqualTo("Hello");
   }
 
@@ -245,7 +243,10 @@ public final class BinderChannelSmokeTest {
     channel =
         BinderChannelBuilder.forAddress(
                 AndroidComponentAddress.forBindIntent(
-                    new Intent().setAction("action1").setPackage(appContext.getPackageName())),
+                    new Intent()
+                        .setAction("action1")
+                        .setData(Uri.parse("scheme://authority/path"))
+                        .setPackage(appContext.getPackageName())),
                 appContext)
             .build();
     assertThat(doCall("Hello").get()).isEqualTo("Hello");

binder/src/androidTest/java/io/grpc/binder/HostServices.java

@@ -29,6 +29,7 @@ import android.os.RemoteException;
 import androidx.lifecycle.LifecycleService;
 import com.google.auto.value.AutoValue;
 import com.google.common.base.Supplier;
+import com.google.errorprone.annotations.concurrent.GuardedBy;
 import io.grpc.Server;
 import java.io.IOException;
 import java.util.HashMap;
@@ -38,7 +39,6 @@ import java.util.concurrent.Executor;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import javax.annotation.Nullable;
-import javax.annotation.concurrent.GuardedBy;
 
 /**
  * A test helper class for creating android services to host gRPC servers.

binder/src/androidTest/java/io/grpc/binder/internal/BinderClientTransportTest.java

@@ -17,6 +17,7 @@
 package io.grpc.binder.internal;
 
 import static com.google.common.truth.Truth.assertThat;
+import static java.util.concurrent.TimeUnit.SECONDS;
 
 import android.content.Context;
 import android.os.DeadObjectException;
@@ -24,9 +25,9 @@ import android.os.Parcel;
 import android.os.RemoteException;
 import androidx.test.core.app.ApplicationProvider;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
-import com.google.common.util.concurrent.Futures;
-import com.google.common.util.concurrent.ListenableFuture;
 import com.google.common.util.concurrent.SettableFuture;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
+import com.google.errorprone.annotations.concurrent.GuardedBy;
 import com.google.protobuf.Empty;
 import io.grpc.CallOptions;
 import io.grpc.ClientStreamTracer;
@@ -37,13 +38,13 @@ import io.grpc.ServerServiceDefinition;
 import io.grpc.Status;
 import io.grpc.Status.Code;
 import io.grpc.binder.AndroidComponentAddress;
-import io.grpc.binder.AsyncSecurityPolicy;
 import io.grpc.binder.BinderServerBuilder;
 import io.grpc.binder.HostServices;
 import io.grpc.binder.SecurityPolicy;
 import io.grpc.binder.internal.OneWayBinderProxies.BlackHoleOneWayBinderProxy;
 import io.grpc.binder.internal.OneWayBinderProxies.BlockingBinderDecorator;
 import io.grpc.binder.internal.OneWayBinderProxies.ThrowingOneWayBinderProxy;
+import io.grpc.binder.internal.SettableAsyncSecurityPolicy.AuthRequest;
 import io.grpc.internal.ClientStream;
 import io.grpc.internal.ClientStreamListener;
 import io.grpc.internal.ClientTransportFactory.ClientTransportOptions;
@@ -62,9 +63,7 @@ import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.TimeUnit;
 import javax.annotation.Nullable;
-import javax.annotation.concurrent.GuardedBy;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -101,7 +100,7 @@ public final class BinderClientTransportTest {
           .build();
 
   AndroidComponentAddress serverAddress;
-  BinderTransport.BinderClientTransport transport;
+  BinderClientTransport transport;
   BlockingSecurityPolicy blockingSecurityPolicy = new BlockingSecurityPolicy();
 
   private final ObjectPool<ScheduledExecutorService> executorServicePool =
@@ -154,23 +153,32 @@ public final class BinderClientTransportTest {
             .setScheduledExecutorPool(executorServicePool)
             .setOffloadExecutorPool(offloadServicePool);
 
+    @CanIgnoreReturnValue
     public BinderClientTransportBuilder setSecurityPolicy(SecurityPolicy securityPolicy) {
       factoryBuilder.setSecurityPolicy(securityPolicy);
       return this;
     }
 
+    @CanIgnoreReturnValue
     public BinderClientTransportBuilder setBinderDecorator(
         OneWayBinderProxy.Decorator binderDecorator) {
       factoryBuilder.setBinderDecorator(binderDecorator);
       return this;
     }
 
+    @CanIgnoreReturnValue
     public BinderClientTransportBuilder setReadyTimeoutMillis(int timeoutMillis) {
       factoryBuilder.setReadyTimeoutMillis(timeoutMillis);
       return this;
     }
 
-    public BinderTransport.BinderClientTransport build() {
+    @CanIgnoreReturnValue
+    public BinderClientTransportBuilder setPreAuthorizeServer(boolean preAuthorizeServer) {
+      factoryBuilder.setPreAuthorizeServers(preAuthorizeServer);
+      return this;
+    }
+
+    public BinderClientTransport build() {
       return factoryBuilder
           .buildClientTransportFactory()
           .newClientTransport(serverAddress, new ClientTransportOptions(), null);
@@ -189,7 +197,7 @@ public final class BinderClientTransportTest {
   private static void shutdownAndTerminate(ExecutorService executorService)
       throws InterruptedException {
     executorService.shutdownNow();
-    if (!executorService.awaitTermination(TIMEOUT_SECONDS, TimeUnit.SECONDS)) {
+    if (!executorService.awaitTermination(TIMEOUT_SECONDS, SECONDS)) {
       throw new AssertionError("executor failed to terminate promptly");
     }
   }
@@ -370,27 +378,58 @@ public final class BinderClientTransportTest {
   }
 
   @Test
-  public void testBlackHoleSecurityPolicyConnectTimeout() throws Exception {
+  public void testBlackHoleSecurityPolicyAuthTimeout() throws Exception {
+    SettableAsyncSecurityPolicy securityPolicy = new SettableAsyncSecurityPolicy();
     transport =
         new BinderClientTransportBuilder()
-            .setSecurityPolicy(blockingSecurityPolicy)
+            .setSecurityPolicy(securityPolicy)
+            .setPreAuthorizeServer(false)
             .setReadyTimeoutMillis(1_234)
             .build();
     transport.start(transportListener).run();
+    // Take the next authRequest but don't respond to it, in order to trigger the ready timeout.
+    AuthRequest authRequest = securityPolicy.takeNextAuthRequest(TIMEOUT_SECONDS, SECONDS);
+
     Status transportStatus = transportListener.awaitShutdown();
     assertThat(transportStatus.getCode()).isEqualTo(Code.DEADLINE_EXCEEDED);
     assertThat(transportStatus.getDescription()).contains("1234");
     transportListener.awaitTermination();
-    blockingSecurityPolicy.provideNextCheckAuthorizationResult(Status.OK);
+    // If the transport gave up waiting on auth, it should cancel its request.
+    assertThat(authRequest.isCancelled()).isTrue();
   }
 
   @Test
-  public void testAsyncSecurityPolicyFailure() throws Exception {
+  public void testBlackHoleSecurityPolicyPreAuthTimeout() throws Exception {
     SettableAsyncSecurityPolicy securityPolicy = new SettableAsyncSecurityPolicy();
-    transport = new BinderClientTransportBuilder().setSecurityPolicy(securityPolicy).build();
-    RuntimeException exception = new NullPointerException();
-    securityPolicy.setAuthorizationException(exception);
+    transport =
+        new BinderClientTransportBuilder()
+            .setSecurityPolicy(securityPolicy)
+            .setPreAuthorizeServer(true)
+            .setReadyTimeoutMillis(1_234)
+            .build();
     transport.start(transportListener).run();
+    // Take the next authRequest but don't respond to it, in order to trigger the ready timeout.
+    AuthRequest preAuthRequest = securityPolicy.takeNextAuthRequest(TIMEOUT_SECONDS, SECONDS);
+
+    Status transportStatus = transportListener.awaitShutdown();
+    assertThat(transportStatus.getCode()).isEqualTo(Code.DEADLINE_EXCEEDED);
+    assertThat(transportStatus.getDescription()).contains("1234");
+    transportListener.awaitTermination();
+    // If the transport gave up waiting on auth, it should cancel its request.
+    assertThat(preAuthRequest.isCancelled()).isTrue();
+  }
+
+  @Test
+  public void testAsyncSecurityPolicyAuthFailure() throws Exception {
+    SettableAsyncSecurityPolicy securityPolicy = new SettableAsyncSecurityPolicy();
+    transport =
+        new BinderClientTransportBuilder()
+            .setPreAuthorizeServer(false)
+            .setSecurityPolicy(securityPolicy)
+            .build();
+    RuntimeException exception = new NullPointerException();
+    transport.start(transportListener).run();
+    securityPolicy.takeNextAuthRequest(TIMEOUT_SECONDS, SECONDS).setResult(exception);
     Status transportStatus = transportListener.awaitShutdown();
     assertThat(transportStatus.getCode()).isEqualTo(Code.INTERNAL);
     assertThat(transportStatus.getCause()).isEqualTo(exception);
@@ -398,19 +437,72 @@ public final class BinderClientTransportTest {
   }
 
   @Test
-  public void testAsyncSecurityPolicySuccess() throws Exception {
+  public void testAsyncSecurityPolicyPreAuthFailure() throws Exception {
     SettableAsyncSecurityPolicy securityPolicy = new SettableAsyncSecurityPolicy();
-    transport = new BinderClientTransportBuilder().setSecurityPolicy(securityPolicy).build();
-    securityPolicy.setAuthorizationResult(Status.PERMISSION_DENIED);
+    transport =
+        new BinderClientTransportBuilder()
+            .setPreAuthorizeServer(true)
+            .setSecurityPolicy(securityPolicy)
+            .build();
+    RuntimeException exception = new NullPointerException();
     transport.start(transportListener).run();
+    securityPolicy.takeNextAuthRequest(TIMEOUT_SECONDS, SECONDS).setResult(exception);
     Status transportStatus = transportListener.awaitShutdown();
-    assertThat(transportStatus.getCode()).isEqualTo(Code.PERMISSION_DENIED);
+    assertThat(transportStatus.getCode()).isEqualTo(Code.INTERNAL);
+    assertThat(transportStatus.getCause()).isEqualTo(exception);
     transportListener.awaitTermination();
   }
 
+  @Test
+  public void testAsyncSecurityPolicyAuthSuccess() throws Exception {
+    SettableAsyncSecurityPolicy securityPolicy = new SettableAsyncSecurityPolicy();
+    transport =
+        new BinderClientTransportBuilder()
+            .setPreAuthorizeServer(false)
+            .setSecurityPolicy(securityPolicy)
+            .build();
+    transport.start(transportListener).run();
+    securityPolicy
+        .takeNextAuthRequest(TIMEOUT_SECONDS, SECONDS)
+        .setResult(Status.PERMISSION_DENIED.withDescription("xyzzy"));
+    Status transportStatus = transportListener.awaitShutdown();
+    assertThat(transportStatus.getCode()).isEqualTo(Code.PERMISSION_DENIED);
+    assertThat(transportStatus.getDescription()).contains("xyzzy");
+    transportListener.awaitTermination();
+  }
+
+  @Test
+  public void testAsyncSecurityPolicyPreAuthSuccess() throws Exception {
+    SettableAsyncSecurityPolicy securityPolicy = new SettableAsyncSecurityPolicy();
+    transport =
+        new BinderClientTransportBuilder()
+            .setPreAuthorizeServer(true)
+            .setSecurityPolicy(securityPolicy)
+            .build();
+    transport.start(transportListener).run();
+    securityPolicy
+        .takeNextAuthRequest(TIMEOUT_SECONDS, SECONDS)
+        .setResult(Status.PERMISSION_DENIED.withDescription("xyzzy"));
+    Status transportStatus = transportListener.awaitShutdown();
+    assertThat(transportStatus.getCode()).isEqualTo(Code.PERMISSION_DENIED);
+    assertThat(transportStatus.getDescription()).contains("xyzzy");
+    transportListener.awaitTermination();
+  }
+
+  @Test
+  public void testAsyncSecurityPolicyCancelledUponExternalTermination() throws Exception {
+    SettableAsyncSecurityPolicy securityPolicy = new SettableAsyncSecurityPolicy();
+    transport = new BinderClientTransportBuilder().setSecurityPolicy(securityPolicy).build();
+    transport.start(transportListener).run();
+    AuthRequest authRequest = securityPolicy.takeNextAuthRequest(TIMEOUT_SECONDS, SECONDS);
+    transport.shutdownNow(Status.UNAVAILABLE); // 'authRequest' remains unanswered!
+    transportListener.awaitShutdown();
+    transportListener.awaitTermination();
+    assertThat(authRequest.isCancelled()).isTrue();
+  }
+
   private static void startAndAwaitReady(
-      BinderTransport.BinderClientTransport transport, TestTransportListener transportListener)
-      throws Exception {
+      BinderClientTransport transport, TestTransportListener transportListener) throws Exception {
     transport.start(transportListener).run();
     transportListener.awaitReady();
   }
@@ -429,7 +521,7 @@ public final class BinderClientTransportTest {
     }
 
     public Status awaitShutdown() throws Exception {
-      return shutdownStatus.get(TIMEOUT_SECONDS, TimeUnit.SECONDS);
+      return shutdownStatus.get(TIMEOUT_SECONDS, SECONDS);
     }
 
     @Override
@@ -440,7 +532,7 @@ public final class BinderClientTransportTest {
     }
 
     public void awaitTermination() throws Exception {
-      isTerminated.get(TIMEOUT_SECONDS, TimeUnit.SECONDS);
+      isTerminated.get(TIMEOUT_SECONDS, SECONDS);
     }
 
     @Override
@@ -451,7 +543,7 @@ public final class BinderClientTransportTest {
     }
 
     public void awaitReady() throws Exception {
-      isReady.get(TIMEOUT_SECONDS, TimeUnit.SECONDS);
+      isReady.get(TIMEOUT_SECONDS, SECONDS);
     }
 
     @Override
@@ -567,25 +659,4 @@ public final class BinderClientTransportTest {
       }
     }
   }
-
-  /** An AsyncSecurityPolicy that lets a test specify the outcome of checkAuthorizationAsync(). */
-  static class SettableAsyncSecurityPolicy extends AsyncSecurityPolicy {
-    private SettableFuture<Status> result = SettableFuture.create();
-
-    public void clearAuthorizationResult() {
-      result = SettableFuture.create();
-    }
-
-    public boolean setAuthorizationResult(Status status) {
-      return result.set(status);
-    }
-
-    public boolean setAuthorizationException(Throwable t) {
-      return result.setException(t);
-    }
-
-    public ListenableFuture<Status> checkAuthorizationAsync(int uid) {
-      return Futures.nonCancellationPropagating(result);
-    }
-  }
 }

binder/src/androidTest/java/io/grpc/binder/internal/BinderTransportTest.java

@@ -106,8 +106,7 @@ public final class BinderTransportTest extends AbstractTransportTest {
     options.setEagAttributes(eagAttrs());
     options.setChannelLogger(transportLogger());
 
-    return new BinderTransport.BinderClientTransport(
-        builder.buildClientTransportFactory(), addr, options);
+    return new BinderClientTransport(builder.buildClientTransportFactory(), addr, options);
   }
 
   @Test

binder/src/main/java/io/grpc/binder/AndroidComponentAddress.java

@@ -18,10 +18,14 @@ package io.grpc.binder;
 
 import static android.content.Intent.URI_ANDROID_APP_SCHEME;
 import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkState;
 
 import android.content.ComponentName;
 import android.content.Context;
 import android.content.Intent;
+import android.os.UserHandle;
+import com.google.common.base.Objects;
+import io.grpc.ExperimentalApi;
 import java.net.SocketAddress;
 import javax.annotation.Nullable;
 
@@ -41,18 +45,25 @@ import javax.annotation.Nullable;
  * fields, namely, an action of {@link ApiConstants#ACTION_BIND}, an empty category set and null
  * type and data URI.
  *
- * <p>The semantics of {@link #equals(Object)} are the same as {@link Intent#filterEquals(Intent)}.
+ * <p>Optionally contains a {@link UserHandle} that must be considered wherever the {@link Intent}
+ * is evaluated.
+ *
+ * <p>{@link #equals(Object)} uses {@link Intent#filterEquals(Intent)} semantics to compare Intents.
  */
 public final class AndroidComponentAddress extends SocketAddress {
   private static final long serialVersionUID = 0L;
 
   private final Intent bindIntent; // "Explicit", having either a component or package restriction.
 
-  protected AndroidComponentAddress(Intent bindIntent) {
+  @Nullable
+  private final UserHandle targetUser; // null means the same user that hosts this process.
+
+  private AndroidComponentAddress(Intent bindIntent, @Nullable UserHandle targetUser) {
     checkArgument(
         bindIntent.getComponent() != null || bindIntent.getPackage() != null,
         "'bindIntent' must be explicit. Specify either a package or ComponentName.");
     this.bindIntent = bindIntent;
+    this.targetUser = targetUser;
   }
 
   /**
@@ -99,7 +110,7 @@ public final class AndroidComponentAddress extends SocketAddress {
    * @throws IllegalArgumentException if 'intent' isn't "explicit"
    */
   public static AndroidComponentAddress forBindIntent(Intent intent) {
-    return new AndroidComponentAddress(intent.cloneFilter());
+    return new AndroidComponentAddress(intent.cloneFilter(), null);
   }
 
   /**
@@ -108,7 +119,7 @@ public final class AndroidComponentAddress extends SocketAddress {
    */
   public static AndroidComponentAddress forComponent(ComponentName component) {
     return new AndroidComponentAddress(
-        new Intent(ApiConstants.ACTION_BIND).setComponent(component));
+        new Intent(ApiConstants.ACTION_BIND).setComponent(component), null);
   }
 
   /**
@@ -141,6 +152,9 @@ public final class AndroidComponentAddress extends SocketAddress {
   /**
    * Returns this address as an explicit {@link Intent} suitable for passing to {@link
    * Context#bindService}.
+   *
+   * <p>NB: The returned Intent does not specify a target Android user. If {@link #getTargetUser()}
+   * is non-null, {@link Context#bindServiceAsUser} should be called instead.
    */
   public Intent asBindIntent() {
     return bindIntent.cloneFilter(); // Intent is mutable so return a copy.
@@ -177,13 +191,92 @@ public final class AndroidComponentAddress extends SocketAddress {
   public boolean equals(Object obj) {
     if (obj instanceof AndroidComponentAddress) {
       AndroidComponentAddress that = (AndroidComponentAddress) obj;
-      return bindIntent.filterEquals(that.bindIntent);
+      return bindIntent.filterEquals(that.bindIntent)
+          && Objects.equal(this.targetUser, that.targetUser);
     }
     return false;
   }
 
   @Override
   public String toString() {
-    return "AndroidComponentAddress[" + bindIntent + "]";
+    StringBuilder builder = new StringBuilder("AndroidComponentAddress[");
+    if (targetUser != null) {
+      builder.append(targetUser);
+      builder.append("@");
+    }
+    builder.append(bindIntent);
+    builder.append("]");
+    return builder.toString();
+  }
+
+  /**
+   * Identifies the Android user in which the bind Intent will be evaluated.
+   *
+   * <p>Returns the {@link UserHandle}, or null which means that the Android user hosting the
+   * current process will be used.
+   */
+  @ExperimentalApi("https://github.com/grpc/grpc-java/issues/10173")
+  @Nullable
+  public UserHandle getTargetUser() {
+    return targetUser;
+  }
+
+  public static Builder newBuilder() {
+    return new Builder();
+  }
+
+  /** Fluently builds instances of {@link AndroidComponentAddress}. */
+  public static class Builder {
+    Intent bindIntent;
+    UserHandle targetUser;
+
+    /**
+     * Sets the binding {@link Intent} to one having the "filter matching" fields of 'intent'.
+     *
+     * <p>'intent' must be "explicit", i.e. having either a target component ({@link
+     * Intent#getComponent()}) or package restriction ({@link Intent#getPackage()}).
+     */
+    public Builder setBindIntent(Intent intent) {
+      this.bindIntent = intent.cloneFilter();
+      return this;
+    }
+
+    /**
+     * Sets the binding {@link Intent} to one with the specified 'component' and default values for
+     * all other fields, for convenience.
+     */
+    public Builder setBindIntentFromComponent(ComponentName component) {
+      this.bindIntent = new Intent(ApiConstants.ACTION_BIND).setComponent(component);
+      return this;
+    }
+
+    /**
+     * Specifies the Android user in which the built Address' bind Intent will be evaluated.
+     *
+     * <p>Connecting to a server in a different Android user is uncommon and requires the client app
+     * have runtime visibility of &#064;SystemApi's and hold certain &#064;SystemApi permissions.
+     * The device must also be running Android SDK version 30 or higher.
+     *
+     * <p>See https://developer.android.com/guide/app-compatibility/restrictions-non-sdk-interfaces
+     * for details on which apps can call the underlying &#064;SystemApi's needed to make this type
+     * of connection.
+     *
+     * <p>One of the "android.permission.INTERACT_ACROSS_XXX" permissions is required. The exact one
+     * depends on the calling user's relationship to the target user, whether client and server are
+     * in the same or different apps, and the version of Android in use. See {@link
+     * Context#bindServiceAsUser}, the essential underlying Android API, for details.
+     */
+    @ExperimentalApi("https://github.com/grpc/grpc-java/issues/10173")
+    public Builder setTargetUser(@Nullable UserHandle targetUser) {
+      this.targetUser = targetUser;
+      return this;
+    }
+
+    public AndroidComponentAddress build() {
+      // We clone any incoming mutable intent in the setter, not here. AndroidComponentAddress
+      // itself is immutable so multiple instances built from here can safely share 'bindIntent'.
+      checkState(bindIntent != null, "Required property 'bindIntent' unset");
+      return new AndroidComponentAddress(bindIntent, targetUser);
+    }
   }
 }

binder/src/main/java/io/grpc/binder/ApiConstants.java

@@ -17,7 +17,11 @@
 package io.grpc.binder;
 
 import android.content.Intent;
+import android.os.UserHandle;
+import io.grpc.Attributes;
+import io.grpc.EquivalentAddressGroup;
 import io.grpc.ExperimentalApi;
+import io.grpc.NameResolver;
 
 /** Constant parts of the gRPC binder transport public API. */
 @ExperimentalApi("https://github.com/grpc/grpc-java/issues/8022")
@@ -29,4 +33,43 @@ public final class ApiConstants {
    * themselves in a {@link android.app.Service#onBind(Intent)} call.
    */
   public static final String ACTION_BIND = "grpc.io.action.BIND";
+
+  /**
+   * Gives a {@link NameResolver} access to its Channel's "source" {@link android.content.Context},
+   * the entry point to almost every other Android API.
+   *
+   * <p>This argument is set automatically by {@link BinderChannelBuilder}. Any value passed to
+   * {@link io.grpc.ManagedChannelBuilder#setNameResolverArg} will be ignored.
+   *
+   * <p>See {@link BinderChannelBuilder#forTarget(String, android.content.Context)} for more.
+   */
+  public static final NameResolver.Args.Key<android.content.Context> SOURCE_ANDROID_CONTEXT =
+      NameResolver.Args.Key.create("source-android-context");
+
+  /**
+   * Specifies the Android user in which target URIs should be resolved.
+   *
+   * <p>{@link UserHandle} can't reasonably be encoded in a target URI string. Instead, all {@link
+   * io.grpc.NameResolverProvider}s producing {@link AndroidComponentAddress}es should let clients
+   * address servers in another Android user using this argument.
+   *
+   * <p>Connecting to a server in a different Android user is uncommon and can only be done by a
+   * "system app" client with special permissions. See {@link
+   * AndroidComponentAddress.Builder#setTargetUser(UserHandle)} for details.
+   */
+  @ExperimentalApi("https://github.com/grpc/grpc-java/issues/10173")
+  public static final NameResolver.Args.Key<UserHandle> TARGET_ANDROID_USER =
+      NameResolver.Args.Key.create("target-android-user");
+
+  /**
+   * Lets you override a Channel's pre-auth configuration (see {@link
+   * BinderChannelBuilder#preAuthorizeServers(boolean)}) for a given {@link EquivalentAddressGroup}.
+   *
+   * <p>A {@link NameResolver} that discovers servers from an untrusted source like PackageManager
+   * can use this to force server pre-auth and prevent abuse.
+   */
+  @EquivalentAddressGroup.Attr
+  @ExperimentalApi("https://github.com/grpc/grpc-java/issues/12191")
+  public static final Attributes.Key<Boolean> PRE_AUTH_SERVER_OVERRIDE =
+      Attributes.Key.create("pre-auth-server-override");
 }

binder/src/main/java/io/grpc/binder/AsyncSecurityPolicy.java

@@ -17,11 +17,11 @@
 package io.grpc.binder;
 
 import com.google.common.util.concurrent.ListenableFuture;
+import com.google.errorprone.annotations.CheckReturnValue;
 import io.grpc.ExperimentalApi;
 import io.grpc.Status;
 import java.util.concurrent.CancellationException;
 import java.util.concurrent.ExecutionException;
-import javax.annotation.CheckReturnValue;
 
 /**
  * Decides whether a given Android UID is authorized to access some resource.
@@ -67,4 +67,25 @@ public abstract class AsyncSecurityPolicy extends SecurityPolicy {
    *     authorized.
    */
   public abstract ListenableFuture<Status> checkAuthorizationAsync(int uid);
+
+  /**
+   * Decides whether the given Android UID is authorized, without providing its raw integer value.
+   *
+   * <p>Calling this is equivalent to calling {@link SecurityPolicy#checkAuthorization(int)}, except
+   * the caller provides a {@link PeerUid} wrapper instead of the raw integer uid (known only to the
+   * transport). This allows a server to check additional application-layer security policy for
+   * itself *after* the call itself is authorized by the transport layer. Cross cutting application-
+   * layer checks could be done from a {@link io.grpc.ServerInterceptor}. Checks based on the
+   * substance of a request message could be done by the individual RPC method implementations
+   * themselves.
+   *
+   * <p>See #checkAuthorizationAsync(int) for details on the semantics. See {@link
+   * PeerUids#newPeerIdentifyingServerInterceptor()} for how to get a {@link PeerUid}.
+   *
+   * @param uid The Android UID to authenticate.
+   * @return A gRPC {@link Status} object, with OK indicating authorized.
+   */
+  public final ListenableFuture<Status> checkAuthorizationAsync(PeerUid uid) {
+    return checkAuthorizationAsync(uid.getUid());
+  }
 }

binder/src/main/java/io/grpc/binder/BinderChannelBuilder.java

@@ -236,20 +236,28 @@ public final class BinderChannelBuilder extends ForwardingChannelBuilder<BinderC
   }
 
   /**
-   * Provides the target {@UserHandle} of the remote Android service.
+   * Specifies the {@link UserHandle} to be searched for the remote Android Service by default.
    *
-   * <p>When targetUserHandle is set, Context.bindServiceAsUser will used and additional Android
-   * permissions will be required. If your usage does not require cross-user communications, please
-   * do not set this field. It is the caller's responsibility to make sure that it holds the
-   * corresponding permissions.
+   * <p>Used only as a fallback if the direct or resolved {@link AndroidComponentAddress} doesn't
+   * specify a {@link UserHandle}. If neither the Channel nor the {@link AndroidComponentAddress}
+   * specifies a target user, the {@link UserHandle} of the current process will be used.
    *
+   * <p>Connecting to a server in a different Android user is uncommon and can only be done by a
+   * "system app" client with special permissions. See {@link
+   * AndroidComponentAddress.Builder#setTargetUser(UserHandle)} for details.
+   *
+   * @deprecated This method's name is misleading because it implies an impersonated client identity
+   *     when it's actually specifying part of the server's location. It's also no longer necessary
+   *     since the target user is part of {@link AndroidComponentAddress}. Prefer to specify target
+   *     user in the address instead, either directly or via a {@link io.grpc.NameResolverProvider}.
    * @param targetUserHandle the target user to bind into.
    * @return this
    */
   @ExperimentalApi("https://github.com/grpc/grpc-java/issues/10173")
   @RequiresApi(30)
+  @Deprecated
   public BinderChannelBuilder bindAsUser(UserHandle targetUserHandle) {
-    transportFactoryBuilder.setTargetUserHandle(targetUserHandle);
+    transportFactoryBuilder.setDefaultTargetUserHandle(targetUserHandle);
     return this;
   }
 
@@ -271,6 +279,35 @@ public final class BinderChannelBuilder extends ForwardingChannelBuilder<BinderC
     return this;
   }
 
+  /**
+   * Checks servers against this Channel's {@link SecurityPolicy} *before* binding.
+   *
+   * <p>Android users can be tricked into installing a malicious app with the same package name as a
+   * legitimate server. That's why we don't send calls to a server until it has been authorized by
+   * an appropriate {@link SecurityPolicy}. But merely binding to a malicious server can enable
+   * "keep-alive" and "background activity launch" abuse, even if it's ultimately unauthorized.
+   * Pre-authorization mitigates these threats by performing a preliminary {@link SecurityPolicy}
+   * check against a server app's PackageManager-registered identity without actually creating an
+   * instance of it. This is especially important for security when the server's direct address
+   * isn't known in advance but rather resolved via target URI or discovered by other means.
+   *
+   * <p>Note that, unlike ordinary authorization, pre-authorization is performed against the server
+   * app's UID, not the UID of the process hosting the bound Service. These can be different, most
+   * commonly due to services that set `android:isolatedProcess=true`.
+   *
+   * <p>Pre-authorization is strongly recommended but it remains optional for now because of this
+   * behavior change and the small performance cost.
+   *
+   * <p>The default value of this property is false but it will become true in a future release.
+   * Clients that require a particular behavior should configure it explicitly using this method
+   * rather than relying on the default.
+   */
+  @ExperimentalApi("https://github.com/grpc/grpc-java/issues/12191")
+  public BinderChannelBuilder preAuthorizeServers(boolean preAuthorize) {
+    transportFactoryBuilder.setPreAuthorizeServers(preAuthorize);
+    return this;
+  }
+
   @Override
   public BinderChannelBuilder idleTimeout(long value, TimeUnit unit) {
     checkState(
@@ -284,6 +321,8 @@ public final class BinderChannelBuilder extends ForwardingChannelBuilder<BinderC
   public ManagedChannel build() {
     transportFactoryBuilder.setOffloadExecutorPool(
         managedChannelImplBuilder.getOffloadExecutorPool());
+    setNameResolverArg(
+        ApiConstants.SOURCE_ANDROID_CONTEXT, transportFactoryBuilder.getSourceContext());
     return super.build();
   }
 }

binder/src/main/java/io/grpc/binder/SecurityPolicies.java

@@ -184,7 +184,6 @@ public final class SecurityPolicies {
    * Creates {@link SecurityPolicy} which checks if the app is a device owner app. See {@link
    * DevicePolicyManager}.
    */
-  @RequiresApi(18)
   public static io.grpc.binder.SecurityPolicy isDeviceOwner(Context applicationContext) {
     DevicePolicyManager devicePolicyManager =
         (DevicePolicyManager) applicationContext.getSystemService(Context.DEVICE_POLICY_SERVICE);
@@ -199,7 +198,6 @@ public final class SecurityPolicies {
    * Creates {@link SecurityPolicy} which checks if the app is a profile owner app. See {@link
    * DevicePolicyManager}.
    */
-  @RequiresApi(21)
   public static SecurityPolicy isProfileOwner(Context applicationContext) {
     DevicePolicyManager devicePolicyManager =
         (DevicePolicyManager) applicationContext.getSystemService(Context.DEVICE_POLICY_SERVICE);

binder/src/main/java/io/grpc/binder/SecurityPolicy.java

@@ -16,8 +16,8 @@
 
 package io.grpc.binder;
 
+import com.google.errorprone.annotations.CheckReturnValue;
 import io.grpc.Status;
-import javax.annotation.CheckReturnValue;
 
 /**
  * Decides whether a given Android UID is authorized to access some resource.
@@ -53,4 +53,25 @@ public abstract class SecurityPolicy {
    * @return A gRPC {@link Status} object, with OK indicating authorized.
    */
   public abstract Status checkAuthorization(int uid);
+
+  /**
+   * Decides whether the given Android UID is authorized, without providing its raw integer value.
+   *
+   * <p>Calling this is equivalent to calling {@link SecurityPolicy#checkAuthorization(int)}, except
+   * the caller provides a {@link PeerUid} wrapper instead of the raw integer uid (known only to the
+   * transport). This allows a server to check additional application-layer security policy for
+   * itself *after* the call itself is authorized by the transport layer. Cross cutting application-
+   * layer checks could be done from a {@link io.grpc.ServerInterceptor}. Checks based on the
+   * substance of a request message could be done by the individual RPC method implementations
+   * themselves.
+   *
+   * <p>See #checkAuthorizationAsync(int) for details on the semantics. See {@link
+   * PeerUids#newPeerIdentifyingServerInterceptor()} for how to get a {@link PeerUid}.
+   *
+   * @param uid The Android UID to authenticate.
+   * @return A gRPC {@link Status} object, with OK indicating authorized.
+   */
+  public final Status checkAuthorization(PeerUid uid) {
+    return checkAuthorization(uid.getUid());
+  }
 }

binder/src/main/java/io/grpc/binder/ServerSecurityPolicy.java

@@ -19,10 +19,10 @@ package io.grpc.binder;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListenableFuture;
+import com.google.errorprone.annotations.CheckReturnValue;
 import io.grpc.Status;
 import java.util.HashMap;
 import java.util.Map;
-import javax.annotation.CheckReturnValue;
 
 /**
  * A security policy for a gRPC server.