https://github.com/python/cpython/commit/4d96b4635aeff1b8ad41d41422ce808ce0b... commit: 4d96b4635aeff1b8ad41d41422ce808ce0b971c8 branch: master author: Victor Stinner <vstinner@python.org> committer: GitHub <noreply@github.com> date: 2020-02-01T02:30:25+01:00 summary: bpo-39511: PyThreadState_Clear() calls on_delete (GH-18296) 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 now calls the PyThreadState.on_delete callback. Previously, that happened in PyThreadState_Delete(). The release_sentinel() function is now called when the C API is still fully working. files: A Misc/NEWS.d/next/C API/2020-01-31-16-35-21.bpo-39511.nv9yEn.rst M Doc/c-api/init.rst M Python/pystate.c diff --git a/Doc/c-api/init.rst b/Doc/c-api/init.rst index 7ea48aec009c9..14049ee64205f 100644 --- a/Doc/c-api/init.rst +++ b/Doc/c-api/init.rst @@ -1048,6 +1048,10 @@ All of the following functions must be called after :c:func:`Py_Initialize`. Reset all information in a thread state object. The global interpreter lock must be held. + .. versionchanged:: 3.9 + This function now calls the :c:member:`PyThreadState.on_delete` callback. + Previously, that happened in :c:func:`PyThreadState_Delete`. + .. c:function:: void PyThreadState_Delete(PyThreadState *tstate) diff --git a/Misc/NEWS.d/next/C API/2020-01-31-16-35-21.bpo-39511.nv9yEn.rst b/Misc/NEWS.d/next/C API/2020-01-31-16-35-21.bpo-39511.nv9yEn.rst new file mode 100644 index 0000000000000..14a04875a8894 --- /dev/null +++ b/Misc/NEWS.d/next/C API/2020-01-31-16-35-21.bpo-39511.nv9yEn.rst @@ -0,0 +1,3 @@ +The :c:func:`PyThreadState_Clear` function now calls the +:c:member:`PyThreadState.on_delete` callback. Previously, that happened in +:c:func:`PyThreadState_Delete`. diff --git a/Python/pystate.c b/Python/pystate.c index d792380de4649..ebc17ea5a7219 100644 --- a/Python/pystate.c +++ b/Python/pystate.c @@ -806,6 +806,10 @@ PyThreadState_Clear(PyThreadState *tstate) Py_CLEAR(tstate->async_gen_finalizer); Py_CLEAR(tstate->context); + + if (tstate->on_delete != NULL) { + tstate->on_delete(tstate->on_delete_data); + } } @@ -830,9 +834,7 @@ tstate_delete_common(PyThreadState *tstate, if (tstate->next) tstate->next->prev = tstate->prev; HEAD_UNLOCK(runtime); - if (tstate->on_delete != NULL) { - tstate->on_delete(tstate->on_delete_data); - } + PyMem_RawFree(tstate); if (gilstate->autoInterpreterState &&