/**
* Cancel this context and detach it as the current context from the thread.
*
* @param toAttach context to make current.
* @param cause of cancellation, can be {@code null}.
*/
public void detachAndCancel(Context toAttach, @Nullable Throwable cause) {
try {
detach(toAttach);
} finally {
cancel(cause);
}
}
@Test
public void contextCancellationCancelsStream() throws Exception {
// Attach the context which is recorded when the call is created
Context.CancellableContext cancellableContext = Context.current().withCancellation();
Context previous = cancellableContext.attach();
ClientCallImpl<Void, Void> call =
new ClientCallImpl<Void, Void>(
DESCRIPTOR,
new SerializingExecutor(Executors.newSingleThreadExecutor()),
CallOptions.DEFAULT,
provider,
deadlineCancellationExecutor)
.setDecompressorRegistry(decompressorRegistry);
previous.attach();
call.start(callListener, new Metadata());
Throwable t = new Throwable();
cancellableContext.cancel(t);
verify(stream, times(1)).cancel(statusArgumentCaptor.capture());
verify(stream, times(1)).cancel(statusCaptor.capture());
assertEquals(Status.Code.CANCELLED, statusCaptor.getValue().getCode());
}
@Test
public void statusFromCancelled_returnCancelledIfCauseIsNull() {
Context.CancellableContext cancellableContext = Context.current().withCancellation();
cancellableContext.cancel(null);
assertTrue(cancellableContext.isCancelled());
Status status = statusFromCancelled(cancellableContext);
assertNotNull(status);
assertEquals(Status.Code.CANCELLED, status.getCode());
}
@Test
public void statusFromCancelled_returnStatusAsSetOnCtx() {
Context.CancellableContext cancellableContext = Context.current().withCancellation();
cancellableContext.cancel(Status.DEADLINE_EXCEEDED.withDescription("foo bar").asException());
Status status = statusFromCancelled(cancellableContext);
assertNotNull(status);
assertEquals(Status.Code.DEADLINE_EXCEEDED, status.getCode());
assertEquals("foo bar", status.getDescription());
}
@Test
public void statusFromCancelled_shouldReturnStatusWithCauseAttached() {
Context.CancellableContext cancellableContext = Context.current().withCancellation();
Throwable t = new Throwable();
cancellableContext.cancel(t);
Status status = statusFromCancelled(cancellableContext);
assertNotNull(status);
assertEquals(Status.Code.CANCELLED, status.getCode());
assertSame(t, status.getCause());
}
/** This is a whitebox test, to verify a special case of the implementation. */
@Test
public void statusFromCancelled_StatusUnknownShouldWork() {
Context.CancellableContext cancellableContext = Context.current().withCancellation();
Exception e = Status.UNKNOWN.asException();
cancellableContext.cancel(e);
assertTrue(cancellableContext.isCancelled());
Status status = statusFromCancelled(cancellableContext);
assertNotNull(status);
assertEquals(Status.Code.UNKNOWN, status.getCode());
assertSame(e, status.getCause());
}
@Test
public void contextAlreadyCancelledNotifiesImmediately() throws Exception {
// Attach the context which is recorded when the call is created
Context.CancellableContext cancellableContext = Context.current().withCancellation();
Throwable cause = new Throwable();
cancellableContext.cancel(cause);
Context previous = cancellableContext.attach();
ClientCallImpl<Void, Void> call =
new ClientCallImpl<Void, Void>(
DESCRIPTOR,
new SerializingExecutor(Executors.newSingleThreadExecutor()),
CallOptions.DEFAULT,
provider,
deadlineCancellationExecutor)
.setDecompressorRegistry(decompressorRegistry);
previous.attach();
final SettableFuture<Status> statusFuture = SettableFuture.create();
call.start(
new ClientCall.Listener<Void>() {
@Override
public void onClose(Status status, Metadata trailers) {
statusFuture.set(status);
}
},
new Metadata());
// Caller should receive onClose callback.
Status status = statusFuture.get(5, TimeUnit.SECONDS);
assertEquals(Status.Code.CANCELLED, status.getCode());
assertSame(cause, status.getCause());
// Following operations should be no-op.
call.request(1);
call.sendMessage(null);
call.halfClose();
// Stream should never be created.
verifyZeroInteractions(transport);
try {
call.sendMessage(null);
fail("Call has been cancelled");
} catch (IllegalStateException ise) {
// expected
}
}
@Override
public boolean isCancelled() {
synchronized (this) {
if (cancelled) {
return true;
}
}
// Detect cancellation of parent in the case where we have no listeners and
// record it.
if (super.isCancelled()) {
cancel(super.cancellationCause());
return true;
}
return false;
}
/** Create a cancellable context that has a deadline. */
private CancellableContext(
Context parent, Deadline deadline, ScheduledExecutorService scheduler) {
super(parent, deriveDeadline(parent, deadline), true);
if (DEADLINE_KEY.get(this) == deadline) {
final TimeoutException cause = new TimeoutException("context timed out");
if (!deadline.isExpired()) {
// The parent deadline was after the new deadline so we need to install a listener
// on the new earlier deadline to trigger expiration for this context.
pendingDeadline =
deadline.runOnExpiration(
new Runnable() {
@Override
public void run() {
cancel(cause);
}
},
scheduler);
} else {
// Cancel immediately if the deadline is already expired.
cancel(cause);
}
}
uncancellableSurrogate = new Context(this, EMPTY_ENTRIES);
}