Refactor cancellation of IOCP::OverlappedOperation#14754
Merged
straight-shoota merged 8 commits intocrystal-lang:masterfrom Aug 7, 2024
Merged
Refactor cancellation of IOCP::OverlappedOperation#14754straight-shoota merged 8 commits intocrystal-lang:masterfrom
IOCP::OverlappedOperation#14754straight-shoota merged 8 commits intocrystal-lang:masterfrom
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straight-shoota
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kind:refactor
platform:windows
ysbaddaden
approved these changes
Jun 27, 2024
ysbaddaden
approved these changes
Jul 12, 2024
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When an overlapped operation gets cancelled, we still need to wait for completion of the operation (with status
ERROR_OPERATION_ABORTED) before it can be freed.Previously we stored a reference to cancelled operations in a linked list and removed them when complete. This allows continuing executing the fiber directly after the cancellation is triggered, but it's also quite a bit of overhead.
Also it makes it impossible to allocate operations on the stack.
Cancellation is triggered when an operation times out.
The change in this patch is that after a timeout the fiber is suspended again, expecting completion via the event loop. Then the operation can be freed.
CANCELLEDstate. It's no longer necessary, we only need to distinguish whether a fiber was woken up due to timeout or completion. A follow-up will further simplify the state handling.sleepandsuspend@@cancelledlinked list.IOCP::OverlappedOperationinternalizehandleandwait_for_completion#14724 (comment)