Greetings friends! Today I finally found the time and bravery to have another stab at the ugly thread leak that Padre aquired along with the Task 2.0 rewrite.
After adding extensive additional detail to the tracing around message passing, I believe I managed to isolate the problem to instances when a 'cancel' message (to tell a running task to abort early) arrives after the thread it is being sent to has completed it's ->run phase and sent it's ->stopped message. The stub ->cancel method on Padre::TaskWorker which was designed to catch these stray messages and ignore them failed to return true. The TaskWorker main loop uses a true response to task method calls to indicate that it should continue processing messages (allowing certain tasks that do potentially destructive or resource wasting things to signal that the thread should be terminated and a new worker created rather than recycle the worker). This feature is not in use yet, and so the parent thread expects all children to run forever, except during shutdown. Unfortunately, this thread shutdown occurs without any kind of signal to the parent that the thread is stopping, and so the parent believed the worker was still active. This resulting in the next task after the cancelled one being sent to the worker, but never arriving (which became a red herring during previous fix attempts, as it appeared that THAT task had stalled, and that was somehow to do with the bug). The fix for the leak is embarrasingly simple, with the following line of code added to the end of Padre::TaskWorker::cancel... return 1; With this change, I believe the bug to be fixed. The "restart hung task manager" feature continues, however, to destroy the task manager state if the task manager becomes legitimately stressed. Rather than remove it, I have set the default for the restart hung task manager feature to false instead of true. Anyone with the feature set manually to true should revert to the default. Further, anyone interesting in task heavy things should see if they can overload of break the task manager now the bug is believed to be gone. Thanks, and apologies for the long delay in fixing this. Adam K _______________________________________________ Padre-dev mailing list Padre-dev@perlide.org http://mail.perlide.org/mailman/listinfo/padre-dev
