Implement Windows SemLock in _multiprocessing module by youknowone · Pull Request #7199 · RustPython/RustPython

Add SemLock class using Windows semaphore APIs (CreateSemaphoreW,
WaitForSingleObjectEx, ReleaseSemaphore) so test_multiprocessing
suites are no longer skipped with "lacks a functioning sem_open".
Also add sem_unlink as no-op and flags dict for Windows.

…lity

- recv() now returns bytes instead of int (matching CPython)
- Remove spurious GetLastError() check after CreateSemaphoreW
- Add signal checking during blocking SemLock acquire

When filename is None, __reduce__ was reconstructing a 2-element
(errno, msg) tuple, dropping the winerror at position 3 in the
original args. Use the original args tuple instead, matching CPython.

* Implement Windows SemLock in _multiprocessing module

Add SemLock class using Windows semaphore APIs (CreateSemaphoreW,
WaitForSingleObjectEx, ReleaseSemaphore) so test_multiprocessing
suites are no longer skipped with "lacks a functioning sem_open".
Also add sem_unlink as no-op and flags dict for Windows.

* Fix _multiprocessing recv to return bytes and improve SemLock reliability

- recv() now returns bytes instead of int (matching CPython)
- Remove spurious GetLastError() check after CreateSemaphoreW
- Add signal checking during blocking SemLock acquire

* Include winerror in OSError.__reduce__ on Windows

* Remove expectedFailure for tests now passing with Windows SemLock

* Fix OSError.__reduce__ to preserve winerror when filename is None

When filename is None, __reduce__ was reconstructing a 2-element
(errno, msg) tuple, dropping the winerror at position 3 in the
original args. Use the original args tuple instead, matching CPython.

* Validate maxvalue > 0 in SemLock and document winerror __reduce__ divergence

* Reject embedded null characters in mmap tagname and _winapi file mapping names