bpo-39511: PyThreadState_Clear() calls on_delete #18296
Merged
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PyThreadState.on_delete is a callback used to notify Python when a
thread completes. _thread._set_sentinel() function creates a lock
which is released when the thread completes. It sets on_delete
callback to the internal release_sentinel() function. This lock is
known as Threading._tstate_lock in the threading module.
The release_sentinel() function uses the Python C API. The problem is
that on_delete is called late in the Python finalization, when the C
API is no longer fully working.
The PyThreadState_Clear() function is now responsible to call
PyThreadState.on_delete callback. Previously, PyThreadState_Delete()
was responsible for that.
The release_sentinel() function is now called when the C API is still
fully working.
https://bugs.python.org/issue39511