Make WaitForMultipleEvents atomic when waitAll is true#20
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Make WaitForMultipleEvents atomic when waitAll is true#20
WaitForMultipleEvents atomic when waitAll is true#20Conversation
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Test contributed by @qwertymaster617, see [0] for associated issue. [0]: #9
This patch significantly changes the behavior (and to an extent, the performance) of pevents to more closely mimic the documented behavior of `WaitForMultipleObjects` and `WaitForMultipleObjectsEx`. As reported in #9, the previous behavior did not make any atomicity guarantees when a call to `WaitForMultipleEvents()` was made with `waitAll = true`, and WFME would attempt to serially obtain the events in question, which could lead to a deadlock in case of circular locking and auto-reset events. The WFMO behavior documented on MSDN makes it clear that the Windows implementation does not modify the signalled state of any of the manual or auto reset events being awaited until the WFMO call is ready to return, at which point either the one event in question or all the events being awaited (dependent on `waitAll`) are atomically awaited.
If the initial number of events was zero and waitAll was set, this assertion would fail incorrectly.
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This patch significantly changes the behavior (and to an extent, the
performance) of pevents to more closely mimic the documented behavior of
WaitForMultipleObjectsandWaitForMultipleObjectsEx.As reported in #9, the previous behavior did not make any atomicity
guarantees when a call to
WaitForMultipleEvents()was made withwaitAll = true, and WFME would attempt to serially obtain the eventsin question, which could lead to a deadlock in case of circular locking
and auto-reset events.
The WFMO behavior documented on MSDN makes it clear that the Windows
implementation does not modify the signalled state of any of the manual
or auto reset events being awaited until the WFMO call is ready to
return, at which point either the one event in question or all the
events being awaited (dependent on
waitAll) are atomically awaited.Closes #9