From 74e945ceb48571520d1bef3cf80f0709772fdfe3 Mon Sep 17 00:00:00 2001
From: Carl Mastrangelo <notcarl@google.com>
Date: Wed, 19 Jun 2019 17:23:08 -0700
Subject: [PATCH] core,netty: block server shutdown until the socket is unbound

---
 api/src/main/java/io/grpc/Server.java                   | 9 +++++++--
 core/src/main/java/io/grpc/internal/InternalServer.java | 4 +++-
 netty/src/main/java/io/grpc/netty/NettyServer.java      | 6 ++++++
 3 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/api/src/main/java/io/grpc/Server.java b/api/src/main/java/io/grpc/Server.java
index b648a6e59f..828abb2d0f 100644
--- a/api/src/main/java/io/grpc/Server.java
+++ b/api/src/main/java/io/grpc/Server.java
@@ -29,8 +29,10 @@ import javax.annotation.concurrent.ThreadSafe;
  */
 @ThreadSafe
 public abstract class Server {
+
   /**
-   * Bind and start the server.
+   * Bind and start the server.  After this call returns, clients may begin connecting to the
+   * listening socket(s).
    *
    * @return {@code this} object
    * @throws IllegalStateException if already started
@@ -102,6 +104,8 @@ public abstract class Server {
 
   /**
    * Initiates an orderly shutdown in which preexisting calls continue but new calls are rejected.
+   * After this call returns, this server has released the listening socket(s) and may be reused by
+   * another server.
    *
    * @return {@code this} object
    * @since 1.0.0
@@ -111,7 +115,8 @@ public abstract class Server {
   /**
    * Initiates a forceful shutdown in which preexisting and new calls are rejected. Although
    * forceful, the shutdown process is still not instantaneous; {@link #isTerminated()} will likely
-   * return {@code false} immediately after this method returns.
+   * return {@code false} immediately after this method returns. After this call returns, this
+   * server has released the listening socket(s) and may be reused by another server.
    *
    * @return {@code this} object
    * @since 1.0.0
diff --git a/core/src/main/java/io/grpc/internal/InternalServer.java b/core/src/main/java/io/grpc/internal/InternalServer.java
index c3a1092342..389b24b45a 100644
--- a/core/src/main/java/io/grpc/internal/InternalServer.java
+++ b/core/src/main/java/io/grpc/internal/InternalServer.java
@@ -42,7 +42,9 @@ public interface InternalServer {
   /**
    * Initiates an orderly shutdown of the server. Existing transports continue, but new transports
    * will not be created (once {@link ServerListener#serverShutdown()} callback is called). This
-   * method may only be called once.
+   * method may only be called once.  Blocks until the listening socket(s) have been closed.  If
+   * interrupted, this method will not wait for the close to complete, but it will happen
+   * asynchronously.
    */
   void shutdown();
 
diff --git a/netty/src/main/java/io/grpc/netty/NettyServer.java b/netty/src/main/java/io/grpc/netty/NettyServer.java
index 5236594f56..11bc58bb4c 100644
--- a/netty/src/main/java/io/grpc/netty/NettyServer.java
+++ b/netty/src/main/java/io/grpc/netty/NettyServer.java
@@ -283,6 +283,12 @@ class NettyServer implements InternalServer, InternalWithLogId {
         eventLoopReferenceCounter.release();
       }
     });
+    try {
+      channel.closeFuture().sync();
+    } catch (InterruptedException e) {
+      log.log(Level.FINE, "Interrupted while shutting down", e);
+      Thread.currentThread().interrupt();
+    }
   }
 
   @Override