private void generateAndEnqueueControlFrame(
IStream stream, ControlFrame frame, long timeout, TimeUnit unit, Callback callback) {
try {
// Synchronization is necessary, since we may have concurrent replies
// and those needs to be generated and enqueued atomically in order
// to maintain a correct compression context
synchronized (this) {
ByteBuffer buffer = generator.control(frame);
LOG.debug("Queuing {} on {}", frame, stream);
ControlFrameBytes frameBytes = new ControlFrameBytes(stream, callback, frame, buffer);
if (timeout > 0) frameBytes.task = scheduler.schedule(frameBytes, timeout, unit);
// Special handling for PING frames, they must be sent as soon as possible
if (ControlFrameType.PING == frame.getType()) prepend(frameBytes);
else append(frameBytes);
}
} catch (Exception x) {
notifyCallbackFailed(callback, x);
}
}
