bpo-33005: Fix _PyGILState_Reinit() (GH-6001)
Fix a crash on fork when using a custom memory allocator (ex: using
PYTHONMALLOC env var).
_PyGILState_Reinit() and _PyInterpreterState_Enable() now use the
default RAW memory allocator to allocate a new interpreters mutex on
fork.
(cherry picked from commit 5d92647102fac9e116b98ab8bbc632eeed501c34)
Co-authored-by: Victor Stinner <victor.stinner@gmail.com>
diff --git a/Python/pystate.c b/Python/pystate.c
index a87801f..140d2fb 100644
--- a/Python/pystate.c
+++ b/Python/pystate.c
@@ -103,15 +103,24 @@
_PyInterpreterState_Enable(_PyRuntimeState *runtime)
{
runtime->interpreters.next_id = 0;
- /* Since we only call _PyRuntimeState_Init() once per process
- (see _PyRuntime_Initialize()), we make sure the mutex is
- initialized here. */
+
+ /* Py_Finalize() calls _PyRuntimeState_Fini() which clears the mutex.
+ Create a new mutex if needed. */
if (runtime->interpreters.mutex == NULL) {
+ /* Force default allocator, since _PyRuntimeState_Fini() must
+ use the same allocator than this function. */
+ PyMemAllocatorEx old_alloc;
+ _PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
+
runtime->interpreters.mutex = PyThread_allocate_lock();
+
+ PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
+
if (runtime->interpreters.mutex == NULL) {
return _Py_INIT_ERR("Can't initialize threads for interpreter");
}
}
+
return _Py_INIT_OK();
}
@@ -933,9 +942,19 @@
void
_PyGILState_Reinit(void)
{
+ /* Force default allocator, since _PyRuntimeState_Fini() must
+ use the same allocator than this function. */
+ PyMemAllocatorEx old_alloc;
+ _PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
+
_PyRuntime.interpreters.mutex = PyThread_allocate_lock();
- if (_PyRuntime.interpreters.mutex == NULL)
+
+ PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
+
+ if (_PyRuntime.interpreters.mutex == NULL) {
Py_FatalError("Can't initialize threads for interpreter");
+ }
+
PyThreadState *tstate = PyGILState_GetThisThreadState();
PyThread_tss_delete(&_PyRuntime.gilstate.autoTSSkey);
if (PyThread_tss_create(&_PyRuntime.gilstate.autoTSSkey) != 0) {