core: Fix unused variables

I did not fix the unused statsTraceCtx in
AbstractClientStream2.GetFramer. Instead, I opened
https://github.com/grpc/grpc-java/issues/2896

core/src/main/java/io/grpc/internal/AbstractServerImplBuilder.java

@@ -187,8 +187,7 @@ public abstract class AbstractServerImplBuilder<T extends AbstractServerImplBuil
         firstNonNull(fallbackRegistry, EMPTY_FALLBACK_REGISTRY), transportServer,
         Context.ROOT, firstNonNull(decompressorRegistry, DecompressorRegistry.getDefaultInstance()),
         firstNonNull(compressorRegistry, CompressorRegistry.getDefaultInstance()),
-        transportFilters,
-        GrpcUtil.STOPWATCH_SUPPLIER);
+        transportFilters);
     for (InternalNotifyOnServerBuild notifyTarget : notifyOnBuildList) {
       notifyTarget.notifyOnBuild(server);
     }

core/src/main/java/io/grpc/internal/CensusStreamTracerModule.java

@@ -132,7 +132,7 @@ final class CensusStreamTracerModule {
    * Returns the server tracer factory.
    */
   ServerStreamTracer.Factory getServerTracerFactory() {
-    return new ServerTracerFactory();
+    return serverTracerFactory;
   }
 
   /**

core/src/main/java/io/grpc/internal/ManagedChannelImpl.java

@@ -659,7 +659,7 @@ public final class ManagedChannelImpl extends ManagedChannel implements WithLogI
           "scheduledExecutor is already cleared. Looks like you are calling this method after "
           + "you've already shut down");
       final OobChannel oobChannel = new OobChannel(
-          authority, oobExecutorPool, scheduledExecutorCopy, stopwatchSupplier, channelExecutor);
+          authority, oobExecutorPool, scheduledExecutorCopy, channelExecutor);
       final InternalSubchannel internalSubchannel = new InternalSubchannel(
           addressGroup, authority, userAgent, backoffPolicyProvider, transportFactory,
           scheduledExecutorCopy, stopwatchSupplier, channelExecutor,

core/src/main/java/io/grpc/internal/MessageFramer.java

@@ -178,7 +178,7 @@ public class MessageFramer implements Framer {
     return written;
   }
 
-  private int writeCompressed(InputStream message, int messageLength) throws IOException {
+  private int writeCompressed(InputStream message, int unusedMessageLength) throws IOException {
     BufferChainOutputStream bufferChain = new BufferChainOutputStream();
 
     OutputStream compressingStream = compressor.compress(bufferChain);

core/src/main/java/io/grpc/internal/OobChannel.java

@@ -33,8 +33,6 @@ package io.grpc.internal;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 
-import com.google.common.base.Stopwatch;
-import com.google.common.base.Supplier;
 import io.grpc.Attributes;
 import io.grpc.CallOptions;
 import io.grpc.ClientCall;
@@ -73,7 +71,6 @@ final class OobChannel extends ManagedChannel implements WithLogId {
   private final ObjectPool<? extends Executor> executorPool;
   private final Executor executor;
   private final ScheduledExecutorService deadlineCancellationExecutor;
-  private final Supplier<Stopwatch> stopwatchSupplier;
   private final CountDownLatch terminatedLatch = new CountDownLatch(1);
   private volatile boolean shutdown;
 
@@ -89,14 +86,12 @@ final class OobChannel extends ManagedChannel implements WithLogId {
 
   OobChannel(
       String authority, ObjectPool<? extends Executor> executorPool,
-      ScheduledExecutorService deadlineCancellationExecutor, Supplier<Stopwatch> stopwatchSupplier,
-      ChannelExecutor channelExecutor) {
+      ScheduledExecutorService deadlineCancellationExecutor, ChannelExecutor channelExecutor) {
     this.authority = checkNotNull(authority, "authority");
     this.executorPool = checkNotNull(executorPool, "executorPool");
     this.executor = checkNotNull(executorPool.getObject(), "executor");
     this.deadlineCancellationExecutor = checkNotNull(
         deadlineCancellationExecutor, "deadlineCancellationExecutor");
-    this.stopwatchSupplier = checkNotNull(stopwatchSupplier, "stopwatchSupplier");
     this.delayedTransport = new DelayedClientTransport(executor, channelExecutor);
     this.delayedTransport.start(new ManagedClientTransport.Listener() {
         @Override

core/src/main/java/io/grpc/internal/ServerImpl.java

@@ -40,8 +40,6 @@ import static java.util.concurrent.TimeUnit.NANOSECONDS;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
-import com.google.common.base.Stopwatch;
-import com.google.common.base.Supplier;
 import io.grpc.Attributes;
 import io.grpc.CompressorRegistry;
 import io.grpc.Context;
@@ -110,7 +108,6 @@ public final class ServerImpl extends io.grpc.Server implements WithLogId {
 
   private final DecompressorRegistry decompressorRegistry;
   private final CompressorRegistry compressorRegistry;
-  private final Supplier<Stopwatch> stopwatchSupplier;
 
   /**
    * Construct a server.
@@ -125,8 +122,7 @@ public final class ServerImpl extends io.grpc.Server implements WithLogId {
       InternalHandlerRegistry registry, HandlerRegistry fallbackRegistry,
       InternalServer transportServer, Context rootContext,
       DecompressorRegistry decompressorRegistry, CompressorRegistry compressorRegistry,
-      List<ServerTransportFilter> transportFilters,
-      Supplier<Stopwatch> stopwatchSupplier) {
+      List<ServerTransportFilter> transportFilters) {
     this.executorPool = Preconditions.checkNotNull(executorPool, "executorPool");
     this.timeoutServicePool = Preconditions.checkNotNull(timeoutServicePool, "timeoutServicePool");
     this.registry = Preconditions.checkNotNull(registry, "registry");
@@ -139,7 +135,6 @@ public final class ServerImpl extends io.grpc.Server implements WithLogId {
     this.compressorRegistry = compressorRegistry;
     this.transportFilters = Collections.unmodifiableList(
         new ArrayList<ServerTransportFilter>(transportFilters));
-    this.stopwatchSupplier = Preconditions.checkNotNull(stopwatchSupplier, "stopwatchSupplier");
   }
 
   /**
@@ -423,7 +418,7 @@ public final class ServerImpl extends io.grpc.Server implements WithLogId {
                 context.cancel(null);
                 return;
               }
-              listener = startCall(stream, methodName, method, headers, context, statsTraceCtx);
+              listener = startCall(stream, methodName, method, headers, context);
             } catch (RuntimeException e) {
               stream.close(Status.fromThrowable(e), new Metadata());
               context.cancel(null);
@@ -469,7 +464,7 @@ public final class ServerImpl extends io.grpc.Server implements WithLogId {
     /** Never returns {@code null}. */
     private <ReqT, RespT> ServerStreamListener startCall(ServerStream stream, String fullMethodName,
         ServerMethodDefinition<ReqT, RespT> methodDef, Metadata headers,
-        Context.CancellableContext context, StatsTraceContext statsTraceCtx) {
+        Context.CancellableContext context) {
       // TODO(ejona86): should we update fullMethodName to have the canonical path of the method?
       ServerCallImpl<ReqT, RespT> call = new ServerCallImpl<ReqT, RespT>(
           stream, methodDef.getMethodDescriptor(), headers, context,

core/src/test/java/io/grpc/inprocess/InProcessTransportTest.java

@@ -42,12 +42,12 @@ import org.junit.runners.JUnit4;
 /** Unit tests for {@link InProcessTransport}. */
 @RunWith(JUnit4.class)
 public class InProcessTransportTest extends AbstractTransportTest {
-  private static final String transportName = "perfect-for-testing";
-  private static final String authority = "a-testing-authority";
+  private static final String TRANSPORT_NAME = "perfect-for-testing";
+  private static final String AUTHORITY = "a-testing-authority";
 
   @Override
   protected InternalServer newServer(List<ServerStreamTracer.Factory> streamTracerFactories) {
-    return new InProcessServer(transportName);
+    return new InProcessServer(TRANSPORT_NAME);
   }
 
   @Override
@@ -58,12 +58,12 @@ public class InProcessTransportTest extends AbstractTransportTest {
 
   @Override
   protected String testAuthority(InternalServer server) {
-    return authority;
+    return AUTHORITY;
   }
 
   @Override
   protected ManagedClientTransport newClientTransport(InternalServer server) {
-    return new InProcessTransport(transportName, testAuthority(server));
+    return new InProcessTransport(TRANSPORT_NAME, testAuthority(server));
   }
 
   @Override

core/src/test/java/io/grpc/internal/CensusStreamTracerModuleTest.java

@@ -266,7 +266,7 @@ public class CensusStreamTracerModuleTest {
     ClientCallTracer callTracer = census.newClientCallTracer(clientCtx, methodName);
     Metadata headers = new Metadata();
     // This propagates clientCtx to headers
-    ClientStreamTracer clientTracer = callTracer.newClientStreamTracer(headers);
+    callTracer.newClientStreamTracer(headers);
 
     ServerStreamTracer serverTracer =
         census.getServerTracerFactory().newServerStreamTracer(methodName, headers);

core/src/test/java/io/grpc/internal/MessageFramerTest.java

@@ -43,7 +43,6 @@ import static org.mockito.Mockito.verifyZeroInteractions;
 
 import io.grpc.Codec;
 import io.grpc.StreamTracer;
-import io.grpc.internal.testing.StatsTestUtils.FakeStatsContextFactory;
 import java.io.BufferedInputStream;
 import java.io.ByteArrayInputStream;
 import java.nio.ByteBuffer;
@@ -77,14 +76,12 @@ public class MessageFramerTest {
   private ArgumentCaptor<Long> uncompressedSizeCaptor;
   private BytesWritableBufferAllocator allocator =
       new BytesWritableBufferAllocator(1000, 1000);
-  private FakeStatsContextFactory statsCtxFactory;
   private StatsTraceContext statsTraceCtx;
 
   /** Set up for test. */
   @Before
   public void setUp() {
     MockitoAnnotations.initMocks(this);
-    statsCtxFactory = new FakeStatsContextFactory();
     // MessageDeframerTest tests with a client-side StatsTraceContext, so here we test with a
     // server-side StatsTraceContext.
     statsTraceCtx = new StatsTraceContext(new StreamTracer[]{tracer});

core/src/test/java/io/grpc/internal/ServerImplTest.java

@@ -1033,8 +1033,7 @@ public class ServerImplTest {
   private void createServer(List<ServerTransportFilter> filters) {
     assertNull(server);
     server = new ServerImpl(executorPool, timerPool, registry, fallbackRegistry,
-        transportServer, SERVER_CONTEXT, decompressorRegistry, compressorRegistry, filters,
-        GrpcUtil.STOPWATCH_SUPPLIER);
+        transportServer, SERVER_CONTEXT, decompressorRegistry, compressorRegistry, filters);
   }
 
   private void verifyExecutorsAcquired() {