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QueuTask: prevent unhandled exception from tearing the main loop down #108
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ghost
added
the
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So, there's no guarantee that the person who created the future is going to wait for the result, but I think this is the right tradeoff in behavior. |
| @@ -201,6 +201,7 @@ def set_exception(self, exception): | |||
| self.timer.stop() | |||
| if self.future is not None: | |||
| self.future.set_exception(exception) | |||
| handled = True | |||
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# For future-based work, let's allow the submitter to handle the exception
# gracefully. Since we can't know if that was successful, just assume the
# exception will be handled (or re-raised) by someone awaiting the future.
# This isn't guaranteed, but is a reasonable assumption.There was a problem hiding this comment.
Will do - thanks! In case of QueueTask - this decision makes sense since submit() returns a future instance so it's basically a part of it's public API.
Also in QueueTask.map() we rely on the future to throw to the caller as we call result() on it.
Prior to this patch - raising an exception inside an execute() of a queued task when using futures instead of deferreds, would tear down the whole service thread. This is almost certainly not what we want. The cleanest way to fix this seems to be in the ExecutionContext, where we consider an exception handled if it's set on a future, and let the submitter worry about it.
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Prior to this patch - raising an exception inside an execute() of a
queued
task when using futures instead of deferreds, would tear down the whole
service thread. This is almost certainly not what we want.
The cleanest way to fix this seems to be in the ExecutionContext, where
we consider an exception handled if it's set on a future, and let the
submitter worry about it.