Issue #13156: revert changeset f6feed6ec3f9, which was only relevant for native

TLS implementations, and fails with the ad-hoc TLS implementation when a thread
doesn't have an auto thread state (e.g. a thread created outside of Python
calling into a subinterpreter).

Include/pystate.h

@@ -111,7 +111,6 @@ PyAPI_FUNC(void) PyThreadState_Clear(PyThreadState *);
 PyAPI_FUNC(void) PyThreadState_Delete(PyThreadState *);
 #ifdef WITH_THREAD
 PyAPI_FUNC(void) PyThreadState_DeleteCurrent(void);
-PyAPI_FUNC(void) _PyGILState_Reinit(void);
 #endif
 
 PyAPI_FUNC(PyThreadState *) PyThreadState_Get(void);

Misc/NEWS

@@ -61,10 +61,6 @@ Core and Builtins
 Library
 -------
 
-- Issue #10517: After fork(), reinitialize the TLS used by the PyGILState_*
-  APIs, to avoid a crash with the pthread implementation in RHEL 5.  Patch
-  by Charles-François Natali.
-
 - Issue #11763: don't use difflib in TestCase.assertMultiLineEqual if the
   strings are too long.
 

Modules/signalmodule.c

@@ -976,7 +976,6 @@ void
 PyOS_AfterFork(void)
 {
 #ifdef WITH_THREAD
-    _PyGILState_Reinit();
     PyEval_ReInitThreads();
     main_thread = PyThread_get_thread_ident();
     main_pid = getpid();

Python/pystate.c

@@ -537,23 +537,6 @@ _PyGILState_Fini(void)
     autoInterpreterState = NULL;
 }
 
-/* Reset the TLS key - called by PyOS_AfterFork.
- * This should not be necessary, but some - buggy - pthread implementations
- * don't flush TLS on fork, see issue #10517.
- */
-void
-_PyGILState_Reinit(void)
-{
-    PyThreadState *tstate = PyGILState_GetThisThreadState();
-    PyThread_delete_key(autoTLSkey);
-    if ((autoTLSkey = PyThread_create_key()) == -1)
-        Py_FatalError("Could not allocate TLS entry");
-
-    /* re-associate the current thread state with the new key */
-    if (PyThread_set_key_value(autoTLSkey, (void *)tstate) < 0)
-        Py_FatalError("Couldn't create autoTLSkey mapping");
-}
-
 /* When a thread state is created for a thread by some mechanism other than
    PyGILState_Ensure, it's important that the GILState machinery knows about
    it so it doesn't try to create another thread state for the thread (this is