diff --git a/core/src/main/java/io/grpc/ClientCall.java b/core/src/main/java/io/grpc/ClientCall.java
index f6111a7321..268b9797a1 100644
--- a/core/src/main/java/io/grpc/ClientCall.java
+++ b/core/src/main/java/io/grpc/ClientCall.java
@@ -61,6 +61,16 @@ package io.grpc;
  * {@link Status#CANCELLED CANCELLED}. Otherwise, {@link Listener#onClose Listener.onClose()} is
  * called with whatever status the RPC was finished. We ensure that at most one is called.
  *
+ * <p>Example: A simple Unary (1 request, 1 response) RPC would look like this:
+ * <pre>
+ *   call = channel.newCall(method, callOptions);
+ *   call.start(listener, headers);
+ *   call.sendMessage(message);
+ *   call.halfClose();
+ *   call.request(1);
+ *   // wait for listener.onMessage()
+ * </pre>
+ *
  * @param <ReqT> type of message sent one or more times to the server.
  * @param <RespT> type of message received one or more times from the server.
  */
@@ -157,7 +167,8 @@ public abstract class ClientCall<ReqT, RespT> {
   public abstract void cancel();
 
   /**
-   * Close the call for request message sending. Incoming response messages are unaffected.
+   * Close the call for request message sending. Incoming response messages are unaffected.  This
+   * should be called when no more messages will be sent from the client.
    *
    * @throws IllegalStateException if call is already {@code halfClose()}d or {@link #cancel}ed
    */
diff --git a/core/src/main/java/io/grpc/internal/ServerCallImpl.java b/core/src/main/java/io/grpc/internal/ServerCallImpl.java
index 622174ee05..2c9322c8ed 100644
--- a/core/src/main/java/io/grpc/internal/ServerCallImpl.java
+++ b/core/src/main/java/io/grpc/internal/ServerCallImpl.java
@@ -34,11 +34,13 @@ package io.grpc.internal;
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkState;
 
+import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Throwables;
 
 import io.grpc.Context;
 import io.grpc.Metadata;
 import io.grpc.MethodDescriptor;
+import io.grpc.MethodDescriptor.MethodType;
 import io.grpc.ServerCall;
 import io.grpc.Status;
 
@@ -121,33 +123,45 @@ final class ServerCallImpl<ReqT, RespT> extends ServerCall<RespT> {
     return cancelled;
   }
 
-  ServerStreamListenerImpl newServerStreamListener(ServerCall.Listener<ReqT> listener,
+  ServerStreamListener newServerStreamListener(ServerCall.Listener<ReqT> listener,
       Future<?> timeout) {
-    return new ServerStreamListenerImpl(listener, timeout);
+    return new ServerStreamListenerImpl<ReqT>(this, listener, timeout);
   }
 
   /**
    * All of these callbacks are assumed to called on an application thread, and the caller is
    * responsible for handling thrown exceptions.
    */
-  private class ServerStreamListenerImpl implements ServerStreamListener {
+  @VisibleForTesting
+  static final class ServerStreamListenerImpl<ReqT> implements ServerStreamListener {
+    private final ServerCallImpl<ReqT, ?> call;
     private final ServerCall.Listener<ReqT> listener;
     private final Future<?> timeout;
+    private boolean messageReceived;
 
-    public ServerStreamListenerImpl(ServerCall.Listener<ReqT> listener, Future<?> timeout) {
+    public ServerStreamListenerImpl(
+        ServerCallImpl<ReqT, ?> call, ServerCall.Listener<ReqT> listener, Future<?> timeout) {
+      this.call = checkNotNull(call, "call");
       this.listener = checkNotNull(listener, "listener must not be null");
-      // TODO: check if timeout should not be null
-      this.timeout = timeout;
+      this.timeout = checkNotNull(timeout, "timeout");
     }
 
     @Override
     public void messageRead(final InputStream message) {
       try {
-        if (cancelled) {
+        if (call.cancelled) {
           return;
         }
+        // Special case for unary calls.
+        if (messageReceived && call.method.getType() == MethodType.UNARY) {
+          call.stream.close(Status.INVALID_ARGUMENT.withDescription(
+                  "More than one request messages for unary call or server streaming call"),
+              new Metadata());
+          return;
+        }
+        messageReceived = true;
 
-        listener.onMessage(method.parseRequest(message));
+        listener.onMessage(call.method.parseRequest(message));
       } finally {
         try {
           message.close();
@@ -159,7 +173,7 @@ final class ServerCallImpl<ReqT, RespT> extends ServerCall<RespT> {
 
     @Override
     public void halfClosed() {
-      if (cancelled) {
+      if (call.cancelled) {
         return;
       }
 
@@ -172,14 +186,14 @@ final class ServerCallImpl<ReqT, RespT> extends ServerCall<RespT> {
       if (status.isOk()) {
         listener.onComplete();
       } else {
-        cancelled = true;
+        call.cancelled = true;
         listener.onCancel();
       }
     }
 
     @Override
     public void onReady() {
-      if (cancelled) {
+      if (call.cancelled) {
         return;
       }
       listener.onReady();
diff --git a/core/src/test/java/io/grpc/internal/ServerCallImplTest.java b/core/src/test/java/io/grpc/internal/ServerCallImplTest.java
index 796cd3c506..2742ee28c3 100644
--- a/core/src/test/java/io/grpc/internal/ServerCallImplTest.java
+++ b/core/src/test/java/io/grpc/internal/ServerCallImplTest.java
@@ -31,6 +31,7 @@
 
 package io.grpc.internal;
 
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
@@ -41,13 +42,16 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 import com.google.common.io.CharStreams;
+import com.google.common.util.concurrent.Futures;
 
 import io.grpc.Context;
 import io.grpc.Metadata;
 import io.grpc.MethodDescriptor;
 import io.grpc.MethodDescriptor.Marshaller;
 import io.grpc.MethodDescriptor.MethodType;
+import io.grpc.ServerCall;
 import io.grpc.Status;
+import io.grpc.internal.ServerCallImpl.ServerStreamListenerImpl;
 
 import org.junit.Before;
 import org.junit.Rule;
@@ -55,17 +59,25 @@ import org.junit.Test;
 import org.junit.rules.ExpectedException;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Captor;
 import org.mockito.Mock;
+import org.mockito.Mockito;
 import org.mockito.MockitoAnnotations;
 
 import java.io.ByteArrayInputStream;
 import java.io.InputStream;
 import java.io.InputStreamReader;
+import java.util.concurrent.Future;
 
 @RunWith(JUnit4.class)
 public class ServerCallImplTest {
   @Rule public final ExpectedException thrown = ExpectedException.none();
   @Mock private ServerStream stream;
+  @Mock private ServerCall.Listener<Long> callListener;
+  @Captor private ArgumentCaptor<Status> statusCaptor;
+
+  private final Future<?> timeout = Futures.immediateCancelledFuture();
 
   private ServerCallImpl<Long, Long> call;
   private Context.CancellableContext context;
@@ -186,6 +198,110 @@ public class ServerCallImplTest {
     verify(stream).setMessageCompression(true);
   }
 
+  @Test
+  public void streamListener_halfClosed() {
+    ServerStreamListenerImpl<Long> streamListener =
+        new ServerCallImpl.ServerStreamListenerImpl<Long>(call, callListener, timeout);
+
+    streamListener.halfClosed();
+
+    verify(callListener).onHalfClose();
+  }
+
+  @Test
+  public void streamListener_halfClosed_onlyOnce() {
+    ServerStreamListenerImpl<Long> streamListener =
+        new ServerCallImpl.ServerStreamListenerImpl<Long>(call, callListener, timeout);
+    streamListener.halfClosed();
+    // canceling the call should short circuit future halfClosed() calls.
+    streamListener.closed(Status.CANCELLED);
+
+    streamListener.halfClosed();
+
+    verify(callListener).onHalfClose();
+  }
+
+  @Test
+  public void streamListener_closedOk() {
+    ServerStreamListenerImpl<Long> streamListener =
+        new ServerCallImpl.ServerStreamListenerImpl<Long>(call, callListener, timeout);
+
+    streamListener.closed(Status.OK);
+
+    verify(callListener).onComplete();
+    assertTrue(timeout.isCancelled());
+  }
+
+  @Test
+  public void streamListener_closedCancelled() {
+    ServerStreamListenerImpl<Long> streamListener =
+        new ServerCallImpl.ServerStreamListenerImpl<Long>(call, callListener, timeout);
+
+    streamListener.closed(Status.CANCELLED);
+
+    verify(callListener).onCancel();
+    assertTrue(timeout.isCancelled());
+  }
+
+  @Test
+  public void streamListener_onReady() {
+    ServerStreamListenerImpl<Long> streamListener =
+        new ServerCallImpl.ServerStreamListenerImpl<Long>(call, callListener, timeout);
+
+    streamListener.onReady();
+
+    verify(callListener).onReady();
+  }
+
+  @Test
+  public void streamListener_onReady_onlyOnce() {
+    ServerStreamListenerImpl<Long> streamListener =
+        new ServerCallImpl.ServerStreamListenerImpl<Long>(call, callListener, timeout);
+    streamListener.onReady();
+    // canceling the call should short circuit future halfClosed() calls.
+    streamListener.closed(Status.CANCELLED);
+
+    streamListener.onReady();
+
+    verify(callListener).onReady();
+  }
+
+  @Test
+  public void streamListener_messageRead() {
+    ServerStreamListenerImpl<Long> streamListener =
+        new ServerCallImpl.ServerStreamListenerImpl<Long>(call, callListener, timeout);
+    streamListener.messageRead(method.streamRequest(1234L));
+
+    verify(callListener).onMessage(1234L);
+  }
+
+  @Test
+  public void streamListener_messageRead_unaryFailsOnMultiple() {
+    ServerStreamListenerImpl<Long> streamListener =
+        new ServerCallImpl.ServerStreamListenerImpl<Long>(call, callListener, timeout);
+    streamListener.messageRead(method.streamRequest(1234L));
+    streamListener.messageRead(method.streamRequest(1234L));
+
+    // Makes sure this was only called once.
+    verify(callListener).onMessage(1234L);
+
+    verify(stream).close(statusCaptor.capture(), Mockito.isA(Metadata.class));
+    assertEquals(Status.Code.INVALID_ARGUMENT, statusCaptor.getValue().getCode());
+  }
+
+  @Test
+  public void streamListener_messageRead_onlyOnce() {
+    ServerStreamListenerImpl<Long> streamListener =
+        new ServerCallImpl.ServerStreamListenerImpl<Long>(call, callListener, timeout);
+    streamListener.messageRead(method.streamRequest(1234L));
+    // canceling the call should short circuit future halfClosed() calls.
+    streamListener.closed(Status.CANCELLED);
+
+    streamListener.messageRead(method.streamRequest(1234L));
+
+    verify(callListener).onMessage(1234L);
+  }
+
   private static class LongMarshaller implements Marshaller<Long> {
     @Override
     public InputStream stream(Long value) {
diff --git a/stub/src/main/java/io/grpc/stub/ServerCalls.java b/stub/src/main/java/io/grpc/stub/ServerCalls.java
index dc2a460448..e01de42fa1 100644
--- a/stub/src/main/java/io/grpc/stub/ServerCalls.java
+++ b/stub/src/main/java/io/grpc/stub/ServerCalls.java
@@ -130,22 +130,15 @@ public class ServerCalls {
           Metadata headers) {
         final ResponseObserver<RespT> responseObserver = new ResponseObserver<RespT>(call);
         // We expect only 1 request, but we ask for 2 requests here so that if a misbehaving client
-        // sends more than 1 requests, we will catch it in onMessage() and emit INVALID_ARGUMENT.
+        // sends more than 1 requests, ServerCall will catch it.
         call.request(2);
         return new EmptyServerCallListener<ReqT>() {
           ReqT request;
           @Override
           public void onMessage(ReqT request) {
-            if (this.request == null) {
-              // We delay calling method.invoke() until onHalfClose(), because application may call
-              // close(OK) inside invoke(), while close(OK) is not allowed before onHalfClose().
-              this.request = request;
-            } else {
-              call.close(
-                  Status.INVALID_ARGUMENT.withDescription(
-                      "More than one request messages for unary call or server streaming call"),
-                  new Metadata());
-            }
+            // We delay calling method.invoke() until onHalfClose() to make sure the client
+            // half-closes.
+            this.request = request;
           }
 
           @Override