@Test
public void testNoDeadlockOnShutdown() {
// Force creation of transport
ClientCall<String, Integer> call = channel.newCall(method, CallOptions.DEFAULT);
call.start(mockCallListener, new Metadata.Headers());
call.cancel();
verify(mockTransport).start(transportListenerCaptor.capture());
final ClientTransport.Listener transportListener = transportListenerCaptor.getValue();
final Object lock = new Object();
final CyclicBarrier barrier = new CyclicBarrier(2);
new Thread() {
@Override
public void run() {
synchronized (lock) {
try {
barrier.await();
} catch (Exception ex) {
throw new AssertionError(ex);
}
// To deadlock, a lock would be needed for this call to proceed.
transportListener.transportShutdown(Status.CANCELLED);
}
}
}.start();
doAnswer(
new Answer<Void>() {
@Override
public Void answer(InvocationOnMock invocation) {
// To deadlock, a lock would need to be held while this method is in progress.
try {
barrier.await();
} catch (Exception ex) {
throw new AssertionError(ex);
}
// If deadlock is possible with this setup, this sychronization completes the loop
// because
// the transportShutdown needs a lock that Channel is holding while calling this
// method.
synchronized (lock) {
}
return null;
}
})
.when(mockTransport)
.shutdown();
channel.shutdown();
transportListener.transportTerminated();
}
@Test
public void twoCallsAndGracefulShutdown() {
verifyNoMoreInteractions(mockTransportFactory);
ClientCall<String, Integer> call = channel.newCall(method, CallOptions.DEFAULT);
verifyNoMoreInteractions(mockTransportFactory);
// Create transport and call
ClientTransport mockTransport = mock(ClientTransport.class);
ClientStream mockStream = mock(ClientStream.class);
Metadata.Headers headers = new Metadata.Headers();
when(mockTransportFactory.newClientTransport()).thenReturn(mockTransport);
when(mockTransport.newStream(same(method), same(headers), any(ClientStreamListener.class)))
.thenReturn(mockStream);
call.start(mockCallListener, headers);
verify(mockTransportFactory).newClientTransport();
verify(mockTransport).start(transportListenerCaptor.capture());
ClientTransport.Listener transportListener = transportListenerCaptor.getValue();
verify(mockTransport).newStream(same(method), same(headers), streamListenerCaptor.capture());
ClientStreamListener streamListener = streamListenerCaptor.getValue();
// Second call
ClientCall<String, Integer> call2 = channel.newCall(method, CallOptions.DEFAULT);
ClientStream mockStream2 = mock(ClientStream.class);
Metadata.Headers headers2 = new Metadata.Headers();
when(mockTransport.newStream(same(method), same(headers2), any(ClientStreamListener.class)))
.thenReturn(mockStream2);
call2.start(mockCallListener2, headers2);
verify(mockTransport).newStream(same(method), same(headers2), streamListenerCaptor.capture());
ClientStreamListener streamListener2 = streamListenerCaptor.getValue();
Metadata.Trailers trailers = new Metadata.Trailers();
streamListener2.closed(Status.CANCELLED, trailers);
verify(mockCallListener2, timeout(1000)).onClose(Status.CANCELLED, trailers);
// Shutdown
channel.shutdown();
assertTrue(channel.isShutdown());
assertFalse(channel.isTerminated());
verify(mockTransport).shutdown();
// Further calls should fail without going to the transport
ClientCall<String, Integer> call3 = channel.newCall(method, CallOptions.DEFAULT);
call3.start(mockCallListener3, new Metadata.Headers());
ArgumentCaptor<Status> statusCaptor = ArgumentCaptor.forClass(Status.class);
verify(mockCallListener3, timeout(1000))
.onClose(statusCaptor.capture(), any(Metadata.Trailers.class));
assertSame(Status.Code.UNAVAILABLE, statusCaptor.getValue().getCode());
// Finish shutdown
transportListener.transportShutdown(Status.CANCELLED);
assertFalse(channel.isTerminated());
streamListener.closed(Status.CANCELLED, trailers);
verify(mockCallListener, timeout(1000)).onClose(Status.CANCELLED, trailers);
assertFalse(channel.isTerminated());
transportListener.transportTerminated();
assertTrue(channel.isTerminated());
verifyNoMoreInteractions(mockTransportFactory);
verifyNoMoreInteractions(mockTransport);
verifyNoMoreInteractions(mockStream);
}