diff options
| -rw-r--r-- | Misc/NEWS.d/next/Core_and_Builtins/2024-10-15-15-29-41.gh-issue-124375.wNrWVa.rst | 1 | ||||
| -rw-r--r-- | Python/gc_free_threading.c | 18 |
2 files changed, 13 insertions, 6 deletions
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2024-10-15-15-29-41.gh-issue-124375.wNrWVa.rst b/Misc/NEWS.d/next/Core_and_Builtins/2024-10-15-15-29-41.gh-issue-124375.wNrWVa.rst new file mode 100644 index 0000000..4bd17a6 --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2024-10-15-15-29-41.gh-issue-124375.wNrWVa.rst @@ -0,0 +1 @@ +Fix a crash in the free threading build when the GC runs concurrently with a new thread starting. diff --git a/Python/gc_free_threading.c b/Python/gc_free_threading.c index 38564d9..3814cd4 100644 --- a/Python/gc_free_threading.c +++ b/Python/gc_free_threading.c @@ -420,18 +420,24 @@ merge_queued_objects(_PyThreadStateImpl *tstate, struct collection_state *state) static void process_delayed_frees(PyInterpreterState *interp) { - // In STW status, we can observe the latest write sequence by - // advancing the write sequence immediately. + // While we are in a "stop the world" pause, we can observe the latest + // write sequence by advancing the write sequence immediately. _Py_qsbr_advance(&interp->qsbr); _PyThreadStateImpl *current_tstate = (_PyThreadStateImpl *)_PyThreadState_GET(); _Py_qsbr_quiescent_state(current_tstate->qsbr); + + // Merge the queues from other threads into our own queue so that we can + // process all of the pending delayed free requests at once. HEAD_LOCK(&_PyRuntime); - PyThreadState *tstate = interp->threads.head; - while (tstate != NULL) { - _PyMem_ProcessDelayed(tstate); - tstate = (PyThreadState *)tstate->next; + for (PyThreadState *p = interp->threads.head; p != NULL; p = p->next) { + _PyThreadStateImpl *other = (_PyThreadStateImpl *)p; + if (other != current_tstate) { + llist_concat(¤t_tstate->mem_free_queue, &other->mem_free_queue); + } } HEAD_UNLOCK(&_PyRuntime); + + _PyMem_ProcessDelayed((PyThreadState *)current_tstate); } // Subtract an incoming reference from the computed "gc_refs" refcount. |