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| author | Sam Gross <colesbury@gmail.com> | 2024-07-09 16:11:43 (GMT) |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2024-07-09 16:11:43 (GMT) |
| commit | 9c08f40a613d9aee78de4ce4ec3e125d1496d148 (patch) | |
| tree | 438972207be9c3ca0bf2e746327d5c914d8d16e7 | |
| parent | 649d5b6d7b04607dd17810ac73e8f16720c6dc78 (diff) | |
| download | cpython-9c08f40a613d9aee78de4ce4ec3e125d1496d148.zip cpython-9c08f40a613d9aee78de4ce4ec3e125d1496d148.tar.gz cpython-9c08f40a613d9aee78de4ce4ec3e125d1496d148.tar.bz2 | |
gh-117657: Fix TSAN races in setobject.c (#121511)
The `used` field must be written using atomic stores because `set_len`
and iterators may access the field concurrently without holding the
per-object lock.
| -rw-r--r-- | Objects/setobject.c | 18 | ||||
| -rw-r--r-- | Tools/tsan/suppressions_free_threading.txt | 3 |
2 files changed, 10 insertions, 11 deletions
diff --git a/Objects/setobject.c b/Objects/setobject.c index eb0c404..5d7ad39 100644 --- a/Objects/setobject.c +++ b/Objects/setobject.c @@ -184,14 +184,14 @@ set_add_entry(PySetObject *so, PyObject *key, Py_hash_t hash) found_unused_or_dummy: if (freeslot == NULL) goto found_unused; - so->used++; + FT_ATOMIC_STORE_SSIZE_RELAXED(so->used, so->used + 1); freeslot->key = key; freeslot->hash = hash; return 0; found_unused: so->fill++; - so->used++; + FT_ATOMIC_STORE_SSIZE_RELAXED(so->used, so->used + 1); entry->key = key; entry->hash = hash; if ((size_t)so->fill*5 < mask*3) @@ -357,7 +357,7 @@ set_discard_entry(PySetObject *so, PyObject *key, Py_hash_t hash) old_key = entry->key; entry->key = dummy; entry->hash = -1; - so->used--; + FT_ATOMIC_STORE_SSIZE_RELAXED(so->used, so->used - 1); Py_DECREF(old_key); return DISCARD_FOUND; } @@ -397,7 +397,7 @@ set_empty_to_minsize(PySetObject *so) { memset(so->smalltable, 0, sizeof(so->smalltable)); so->fill = 0; - so->used = 0; + FT_ATOMIC_STORE_SSIZE_RELAXED(so->used, 0); so->mask = PySet_MINSIZE - 1; so->table = so->smalltable; so->hash = -1; @@ -615,7 +615,7 @@ set_merge_lock_held(PySetObject *so, PyObject *otherset) } } so->fill = other->fill; - so->used = other->used; + FT_ATOMIC_STORE_SSIZE_RELAXED(so->used, other->used); return 0; } @@ -624,7 +624,7 @@ set_merge_lock_held(PySetObject *so, PyObject *otherset) setentry *newtable = so->table; size_t newmask = (size_t)so->mask; so->fill = other->used; - so->used = other->used; + FT_ATOMIC_STORE_SSIZE_RELAXED(so->used, other->used); for (i = other->mask + 1; i > 0 ; i--, other_entry++) { key = other_entry->key; if (key != NULL && key != dummy) { @@ -678,7 +678,7 @@ set_pop_impl(PySetObject *so) key = entry->key; entry->key = dummy; entry->hash = -1; - so->used--; + FT_ATOMIC_STORE_SSIZE_RELAXED(so->used, so->used - 1); so->finger = entry - so->table + 1; /* next place to start */ return key; } @@ -1173,7 +1173,9 @@ set_swap_bodies(PySetObject *a, PySetObject *b) Py_hash_t h; t = a->fill; a->fill = b->fill; b->fill = t; - t = a->used; a->used = b->used; b->used = t; + t = a->used; + FT_ATOMIC_STORE_SSIZE_RELAXED(a->used, b->used); + FT_ATOMIC_STORE_SSIZE_RELAXED(b->used, t); t = a->mask; a->mask = b->mask; b->mask = t; u = a->table; diff --git a/Tools/tsan/suppressions_free_threading.txt b/Tools/tsan/suppressions_free_threading.txt index 534a0ce..fb97bdc 100644 --- a/Tools/tsan/suppressions_free_threading.txt +++ b/Tools/tsan/suppressions_free_threading.txt @@ -30,8 +30,6 @@ race_top:assign_version_tag race_top:insertdict race_top:lookup_tp_dict race_top:new_reference -# https://gist.github.com/colesbury/d13d033f413b4ad07929d044bed86c35 -race_top:set_discard_entry race_top:_PyDict_CheckConsistency race_top:_Py_dict_lookup_threadsafe race_top:_multiprocessing_SemLock_acquire_impl @@ -41,7 +39,6 @@ race_top:insert_to_emptydict race_top:insertdict race_top:list_get_item_ref race_top:make_pending_calls -race_top:set_add_entry race_top:_Py_slot_tp_getattr_hook race_top:add_threadstate race_top:dump_traceback |