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gh-152238: Revert gh-150490 and gh-152200. (gh-152232)

Browse source 
Revert commits:
    gh-151593: Fix dead lock in PyDict insert_split_key() (#152200)
    gh-150490: Raise PyType_Modified for insertion into split dictionary (#150489)

For gh-150489, it violates locking discipline and results in deadlocks,
gh-151593 is an example of it being hit in CI.  The attempted fix 
gh-152200 avoids the deadlock but introduces a data-race.  The race
window is small but can be triggered with pure Python code.
This commit is contained in:
Neil Schemenauer 2026-06-26 11:20:41 -07:00 • committed by GitHub
parent 5a549e82b8
commit 9626ef87f4
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
12 changed files with 1412 additions and 1308 deletions
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11
Python/bytecodes.c
View file

@ -4270,6 +4270,13 @@ dummy_func(
EXIT_IF(!FT_ATOMIC_LOAD_UINT8(ivs->valid));
}
op(_GUARD_KEYS_VERSION, (keys_version/2, owner -- owner)) {
PyTypeObject *owner_cls = Py_TYPE(PyStackRef_AsPyObjectBorrow(owner));
PyHeapTypeObject *owner_heap_type = (PyHeapTypeObject *)owner_cls;
PyDictKeysObject *keys = owner_heap_type->ht_cached_keys;
EXIT_IF(FT_ATOMIC_LOAD_UINT32_RELAXED(keys->dk_version) != keys_version);
}
op(_LOAD_ATTR_METHOD_WITH_VALUES, (descr/4, owner -- attr, self)) {
assert(oparg & 1);
/* Cached method object */
@ -4286,7 +4293,7 @@ dummy_func(
_RECORD_TOS_TYPE +
_GUARD_TYPE_VERSION +
_GUARD_DORV_VALUES_INST_ATTR_FROM_DICT +
unused/2 +
_GUARD_KEYS_VERSION +
_LOAD_ATTR_METHOD_WITH_VALUES;
op(_LOAD_ATTR_METHOD_NO_DICT, (descr/4, owner -- attr, self)) {
@ -4320,7 +4327,7 @@ dummy_func(
_RECORD_TOS_TYPE +
_GUARD_TYPE_VERSION +
_GUARD_DORV_VALUES_INST_ATTR_FROM_DICT +
unused/2 +
_GUARD_KEYS_VERSION +
_LOAD_ATTR_NONDESCRIPTOR_WITH_VALUES;
op(_LOAD_ATTR_NONDESCRIPTOR_NO_DICT, (descr/4, owner -- attr)) {

97
Python/executor_cases.c.h generated
View file

@ -16508,6 +16508,103 @@
break;
}
case _GUARD_KEYS_VERSION_r01: {
CHECK_CURRENT_CACHED_VALUES(0);
ASSERT_WITHIN_STACK_BOUNDS_IGNORING_CACHE(__FILE__, __LINE__);
_PyStackRef owner;
owner = stack_pointer[-1];
uint32_t keys_version = (uint32_t)CURRENT_OPERAND0_32();
PyTypeObject *owner_cls = Py_TYPE(PyStackRef_AsPyObjectBorrow(owner));
PyHeapTypeObject *owner_heap_type = (PyHeapTypeObject *)owner_cls;
PyDictKeysObject *keys = owner_heap_type->ht_cached_keys;
if (FT_ATOMIC_LOAD_UINT32_RELAXED(keys->dk_version) != keys_version) {
UOP_STAT_INC(uopcode, miss);
SET_CURRENT_CACHED_VALUES(0);
JUMP_TO_JUMP_TARGET();
}
_tos_cache0 = owner;
SET_CURRENT_CACHED_VALUES(1);
stack_pointer += -1;
ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
ASSERT_WITHIN_STACK_BOUNDS_IGNORING_CACHE(__FILE__, __LINE__);
break;
}
case _GUARD_KEYS_VERSION_r11: {
CHECK_CURRENT_CACHED_VALUES(1);
ASSERT_WITHIN_STACK_BOUNDS_IGNORING_CACHE(__FILE__, __LINE__);
_PyStackRef owner;
_PyStackRef _stack_item_0 = _tos_cache0;
owner = _stack_item_0;
uint32_t keys_version = (uint32_t)CURRENT_OPERAND0_32();
PyTypeObject *owner_cls = Py_TYPE(PyStackRef_AsPyObjectBorrow(owner));
PyHeapTypeObject *owner_heap_type = (PyHeapTypeObject *)owner_cls;
PyDictKeysObject *keys = owner_heap_type->ht_cached_keys;
if (FT_ATOMIC_LOAD_UINT32_RELAXED(keys->dk_version) != keys_version) {
UOP_STAT_INC(uopcode, miss);
_tos_cache0 = owner;
SET_CURRENT_CACHED_VALUES(1);
JUMP_TO_JUMP_TARGET();
}
_tos_cache0 = owner;
SET_CURRENT_CACHED_VALUES(1);
ASSERT_WITHIN_STACK_BOUNDS_IGNORING_CACHE(__FILE__, __LINE__);
break;
}
case _GUARD_KEYS_VERSION_r22: {
CHECK_CURRENT_CACHED_VALUES(2);
ASSERT_WITHIN_STACK_BOUNDS_IGNORING_CACHE(__FILE__, __LINE__);
_PyStackRef owner;
_PyStackRef _stack_item_0 = _tos_cache0;
_PyStackRef _stack_item_1 = _tos_cache1;
owner = _stack_item_1;
uint32_t keys_version = (uint32_t)CURRENT_OPERAND0_32();
PyTypeObject *owner_cls = Py_TYPE(PyStackRef_AsPyObjectBorrow(owner));
PyHeapTypeObject *owner_heap_type = (PyHeapTypeObject *)owner_cls;
PyDictKeysObject *keys = owner_heap_type->ht_cached_keys;
if (FT_ATOMIC_LOAD_UINT32_RELAXED(keys->dk_version) != keys_version) {
UOP_STAT_INC(uopcode, miss);
_tos_cache1 = owner;
_tos_cache0 = _stack_item_0;
SET_CURRENT_CACHED_VALUES(2);
JUMP_TO_JUMP_TARGET();
}
_tos_cache1 = owner;
_tos_cache0 = _stack_item_0;
SET_CURRENT_CACHED_VALUES(2);
ASSERT_WITHIN_STACK_BOUNDS_IGNORING_CACHE(__FILE__, __LINE__);
break;
}
case _GUARD_KEYS_VERSION_r33: {
CHECK_CURRENT_CACHED_VALUES(3);
ASSERT_WITHIN_STACK_BOUNDS_IGNORING_CACHE(__FILE__, __LINE__);
_PyStackRef owner;
_PyStackRef _stack_item_0 = _tos_cache0;
_PyStackRef _stack_item_1 = _tos_cache1;
_PyStackRef _stack_item_2 = _tos_cache2;
owner = _stack_item_2;
uint32_t keys_version = (uint32_t)CURRENT_OPERAND0_32();
PyTypeObject *owner_cls = Py_TYPE(PyStackRef_AsPyObjectBorrow(owner));
PyHeapTypeObject *owner_heap_type = (PyHeapTypeObject *)owner_cls;
PyDictKeysObject *keys = owner_heap_type->ht_cached_keys;
if (FT_ATOMIC_LOAD_UINT32_RELAXED(keys->dk_version) != keys_version) {
UOP_STAT_INC(uopcode, miss);
_tos_cache2 = owner;
_tos_cache1 = _stack_item_1;
_tos_cache0 = _stack_item_0;
SET_CURRENT_CACHED_VALUES(3);
JUMP_TO_JUMP_TARGET();
}
_tos_cache2 = owner;
_tos_cache1 = _stack_item_1;
_tos_cache0 = _stack_item_0;
SET_CURRENT_CACHED_VALUES(3);
ASSERT_WITHIN_STACK_BOUNDS_IGNORING_CACHE(__FILE__, __LINE__);
break;
}
case _LOAD_ATTR_METHOD_WITH_VALUES_r02: {
CHECK_CURRENT_CACHED_VALUES(0);
ASSERT_WITHIN_STACK_BOUNDS_IGNORING_CACHE(__FILE__, __LINE__);

26
Python/generated_cases.c.h generated
View file

@ -9255,7 +9255,18 @@
JUMP_TO_PREDICTED(LOAD_ATTR);
}
}
/* Skip 2 cache entries */
// _GUARD_KEYS_VERSION
{
uint32_t keys_version = read_u32(&this_instr[4].cache);
PyTypeObject *owner_cls = Py_TYPE(PyStackRef_AsPyObjectBorrow(owner));
PyHeapTypeObject *owner_heap_type = (PyHeapTypeObject *)owner_cls;
PyDictKeysObject *keys = owner_heap_type->ht_cached_keys;
if (FT_ATOMIC_LOAD_UINT32_RELAXED(keys->dk_version) != keys_version) {
UPDATE_MISS_STATS(LOAD_ATTR);
assert(_PyOpcode_Deopt[opcode] == (LOAD_ATTR));
JUMP_TO_PREDICTED(LOAD_ATTR);
}
}
// _LOAD_ATTR_METHOD_WITH_VALUES
{
PyObject *descr = read_obj(&this_instr[6].cache);
@ -9440,7 +9451,18 @@
JUMP_TO_PREDICTED(LOAD_ATTR);
}
}
/* Skip 2 cache entries */
// _GUARD_KEYS_VERSION
{
uint32_t keys_version = read_u32(&this_instr[4].cache);
PyTypeObject *owner_cls = Py_TYPE(PyStackRef_AsPyObjectBorrow(owner));
PyHeapTypeObject *owner_heap_type = (PyHeapTypeObject *)owner_cls;
PyDictKeysObject *keys = owner_heap_type->ht_cached_keys;
if (FT_ATOMIC_LOAD_UINT32_RELAXED(keys->dk_version) != keys_version) {
UPDATE_MISS_STATS(LOAD_ATTR);
assert(_PyOpcode_Deopt[opcode] == (LOAD_ATTR));
JUMP_TO_PREDICTED(LOAD_ATTR);
}
}
// _LOAD_ATTR_NONDESCRIPTOR_WITH_VALUES
{
PyObject *descr = read_obj(&this_instr[6].cache);

4
Python/optimizer_cases.c.h generated
View file

@ -3941,6 +3941,10 @@
break;
}
case _GUARD_KEYS_VERSION: {
break;
}
case _LOAD_ATTR_METHOD_WITH_VALUES: {
JitOptRef owner;
JitOptRef attr;

1
Python/specialize.c
View file

@ -1286,6 +1286,7 @@ specialize_attr_loadclassattr(PyObject *owner, _Py_CODEUNIT *instr,
SPECIALIZATION_FAIL(LOAD_ATTR, SPEC_FAIL_OUT_OF_VERSIONS);
return 0;
}
write_u32(cache->keys_version, shared_keys_version);
specialize(instr, is_method ? LOAD_ATTR_METHOD_WITH_VALUES : LOAD_ATTR_NONDESCRIPTOR_WITH_VALUES);
}
else {