kquick
commented
4 years ago I don't think you are necessarily doing anything wrong at this point.
How long does it take the VideoDecoder to do it's work each time it is awoken by the DrumBeat? If it takes the VideoDecoder almost or more than 30ms to do its work then messages (from DrumBeat) may be being queued up enough that it takes a long time for the VideoDecoder to work through the backlog and process the exit request. One way you could test this would be to change the DrumBeat wakeup time from 30ms to something large like 5s; this would obviously have bad effects on your image capture but if the actors exit cleanly in this mode that would support the hypothesis of queueing to reveal a root cause.
Also you referred to an "exitActor message", but the Thespian shutdown sends an ActorExitMessage. There is special handling for ActorExitMessage to ensure that it causes a shutdown even if it is ignored, but if you have a different message for requesting shutdown and the VideoDecoder is ignoring that message (eg. you are using ActorTypeDispatcher and haven't added a receiveMsg_exitMessage method) then Thespian won't know it's an actor shutdown request so it won't enforce a shutdown.
An Actor generally doesn't shutdown until its children shutdown, so it could also be that VideoEncoder is seeing the message but DrumBeat is dropping it (e.g. possibly as described above) and therefore not exiting. Do you use self.wakeupAfter() in DrumBeat or is it doing something blocking like time.sleep()? If it's blocking then it will never process incoming messages (even an ActorExitRequest) and therefore never shutdown, blocking VideoDecoder from shutting down as well.
rbotafogo
Hello....
I'm working on Windows 10 with OpenCV and Thespian to read multiple real time video feeds. Since videos come at 30 FPS I have an Actor per camera capturing the videos. The captured frame is stored on a memory mapped file for processing by other actors. The Actor capturing frames (VideoDecoder) starts a helper Actor (DrumBeat) that beats every 30ms notifying the actor that it should capture a new frame. DrumBeat uses wakeupAfter to beat at the 30ms rhythm. So far, so good...
When I shutdown the system, I see the exitActor message being propagated from the system to all the created Actors. However, VideoDecoder never gets the exitActor message. Seems to me that the wakeup messages from DrumBeat don´t let VideoDecoder receive any other messages. So, VideoDecoder never exists and the same for DrumBeat.
Any ideas on how to exit those processes? Am I doing something wrong?
Thanks