core: pass status to ManagedClientTransport.shutdown() (#3351)

This aligns with shutdownNow(), which is already accepting a status.
The status will be propagated to application when RPCs failed because
of transport shutdown, which will become useful information for debug.

3 files changed, 4 insertions, 7 deletions

diff --git a/netty/src/main/java/io/grpc/netty/NettyClientHandler.java b/netty/src/main/java/io/grpc/netty/NettyClientHandler.java
index 2295b17eb..93b25dbb8 100644
--- a/netty/src/main/java/io/grpc/netty/NettyClientHandler.java
+++ b/netty/src/main/java/io/grpc/netty/NettyClientHandler.java
@@ -540,8 +540,7 @@ class NettyClientHandler extends AbstractNettyHandler {
 
   private void forcefulClose(final ChannelHandlerContext ctx, final ForcefulCloseCommand msg,
       ChannelPromise promise) throws Exception {
-    lifecycleManager.notifyShutdown(
-        Status.UNAVAILABLE.withDescription("Channel requested transport to shut down"));
+    lifecycleManager.notifyShutdown(msg.getStatus());
     close(ctx, promise);
     connection().forEachActiveStream(new Http2StreamVisitor() {
       @Override
diff --git a/netty/src/main/java/io/grpc/netty/NettyClientTransport.java b/netty/src/main/java/io/grpc/netty/NettyClientTransport.java
index 29e30b065..94c31663f 100644
--- a/netty/src/main/java/io/grpc/netty/NettyClientTransport.java
+++ b/netty/src/main/java/io/grpc/netty/NettyClientTransport.java
@@ -248,16 +248,14 @@ class NettyClientTransport implements ConnectionClientTransport {
   }
 
   @Override
-  public void shutdown() {
+  public void shutdown(Status reason) {
     // start() could have failed
     if (channel == null) {
       return;
     }
     // Notifying of termination is automatically done when the channel closes.
     if (channel.isOpen()) {
-      Status status
-          = Status.UNAVAILABLE.withDescription("Channel requested transport to shut down");
-      handler.getWriteQueue().enqueue(new GracefulCloseCommand(status), true);
+      handler.getWriteQueue().enqueue(new GracefulCloseCommand(reason), true);
     }
   }
 
diff --git a/netty/src/test/java/io/grpc/netty/NettyClientTransportTest.java b/netty/src/test/java/io/grpc/netty/NettyClientTransportTest.java
index e805cdd80..5c7362447 100644
--- a/netty/src/test/java/io/grpc/netty/NettyClientTransportTest.java
+++ b/netty/src/test/java/io/grpc/netty/NettyClientTransportTest.java
@@ -118,7 +118,7 @@ public class NettyClientTransportTest {
   public void teardown() throws Exception {
     Context.ROOT.attach();
     for (NettyClientTransport transport : transports) {
-      transport.shutdown();
+      transport.shutdown(Status.UNAVAILABLE);
     }
 
     if (server != null) {