mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-10-14 18:59:46 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 11

gh-127582: Make object resurrection thread-safe for free threading. (GH-127612)

Browse source 
Objects may be temporarily "resurrected" in destructors when calling
finalizers or watcher callbacks. We previously undid the resurrection
by decrementing the reference count using `Py_SET_REFCNT`. This was not
thread-safe because other threads might be accessing the object
(modifying its reference count) if it was exposed by the finalizer,
watcher callback, or temporarily accessed by a racy dictionary or list
access.

This adds internal-only thread-safe functions for temporary object
resurrection during destructors.
This commit is contained in:
Sam Gross 2024-12-05 21:07:31 +00:00 • committed by GitHub
parent 657d0e99aa
commit f4f530804b
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
6 changed files with 87 additions and 20 deletions
Download patch file Download diff file Expand all files Collapse all files

7
Objects/codeobject.c
View file

@ -1867,14 +1867,11 @@ free_monitoring_data(_PyCoMonitoringData *data)
static void
code_dealloc(PyCodeObject *co)
{
assert(Py_REFCNT(co) == 0);
Py_SET_REFCNT(co, 1);
_PyObject_ResurrectStart((PyObject *)co);
notify_code_watchers(PY_CODE_EVENT_DESTROY, co);
if (Py_REFCNT(co) > 1) {
Py_SET_REFCNT(co, Py_REFCNT(co) - 1);
if (_PyObject_ResurrectEnd((PyObject *)co)) {
return;
}
Py_SET_REFCNT(co, 0);
#ifdef Py_GIL_DISABLED
PyObject_GC_UnTrack(co);