Stowage/cpython
2
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2026-02-23 15:42:04 +00:00
Code Issues Projects Releases Packages Wiki Activity

gh-120321: Make gi_frame_state transitions atomic in FT build (gh-142599)

Browse source 
This makes generator frame state transitions atomic in the free
threading build, which avoids segfaults when trying to execute
a generator from multiple threads concurrently.

There are still a few operations that aren't thread-safe and may crash
if performed concurrently on the same generator/coroutine:

 * Accessing gi_yieldfrom/cr_await/ag_await
 * Accessing gi_frame/cr_frame/ag_frame
 * Async generator operations
This commit is contained in:
Sam Gross 2025-12-19 14:10:37 -05:00 • committed by GitHub
parent e2a7db7175
commit 08bc03ff2a
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
16 changed files with 1124 additions and 883 deletions
Download patch file Download diff file Expand all files Collapse all files

94
Python/executor_cases.c.h generated
View file

@ -5823,7 +5823,7 @@
SET_CURRENT_CACHED_VALUES(2);
JUMP_TO_JUMP_TARGET();
}
if (gen->gi_frame_state >= FRAME_EXECUTING) {
if (!gen_try_set_executing((PyGenObject *)gen)) {
UOP_STAT_INC(uopcode, miss);
_tos_cache1 = v;
_tos_cache0 = receiver;
@ -5833,7 +5833,6 @@
STAT_INC(SEND, hit);
_PyInterpreterFrame *pushed_frame = &gen->gi_iframe;
_PyFrame_StackPush(pushed_frame, PyStackRef_MakeHeapSafe(v));
gen->gi_frame_state = FRAME_EXECUTING;
gen->gi_exc_state.previous_item = tstate->exc_info;
tstate->exc_info = &gen->gi_exc_state;
assert( 2u + oparg <= UINT16_MAX);
@ -5861,7 +5860,6 @@
PyGenObject *gen = _PyGen_GetGeneratorFromFrame(frame);
assert(FRAME_SUSPENDED_YIELD_FROM == FRAME_SUSPENDED + 1);
assert(oparg == 0 || oparg == 1);
gen->gi_frame_state = FRAME_SUSPENDED + oparg;
_PyStackRef temp = retval;
_PyFrame_SetStackPointer(frame, stack_pointer);
tstate->exc_info = gen->gi_exc_state.previous_item;
@ -5870,6 +5868,8 @@
_PyInterpreterFrame *gen_frame = frame;
frame = tstate->current_frame = frame->previous;
gen_frame->previous = NULL;
((_PyThreadStateImpl *)tstate)->generator_return_kind = GENERATOR_YIELD;
FT_ATOMIC_STORE_INT8_RELEASE(gen->gi_frame_state, FRAME_SUSPENDED + oparg);
assert(INLINE_CACHE_ENTRIES_SEND == INLINE_CACHE_ENTRIES_FOR_ITER);
#if TIER_ONE
assert(frame->instr_ptr->op.code == INSTRUMENTED_LINE ||
@ -10859,6 +10859,81 @@
break;
}
case _FOR_ITER_GEN_FRAME_r03: {
CHECK_CURRENT_CACHED_VALUES(0);
assert(WITHIN_STACK_BOUNDS_IGNORING_CACHE());
_PyStackRef iter;
_PyStackRef gen_frame;
oparg = CURRENT_OPARG();
iter = stack_pointer[-2];
PyGenObject *gen = (PyGenObject *)PyStackRef_AsPyObjectBorrow(iter);
if (Py_TYPE(gen) != &PyGen_Type) {
UOP_STAT_INC(uopcode, miss);
SET_CURRENT_CACHED_VALUES(0);
JUMP_TO_JUMP_TARGET();
}
if (!gen_try_set_executing((PyGenObject *)gen)) {
UOP_STAT_INC(uopcode, miss);
SET_CURRENT_CACHED_VALUES(0);
JUMP_TO_JUMP_TARGET();
}
STAT_INC(FOR_ITER, hit);
_PyInterpreterFrame *pushed_frame = &gen->gi_iframe;
_PyFrame_StackPush(pushed_frame, PyStackRef_None);
gen->gi_exc_state.previous_item = tstate->exc_info;
tstate->exc_info = &gen->gi_exc_state;
pushed_frame->previous = frame;
frame->return_offset = (uint16_t)( 2u + oparg);
gen_frame = PyStackRef_Wrap(pushed_frame);
_tos_cache2 = gen_frame;
_tos_cache1 = stack_pointer[-1];
_tos_cache0 = iter;
SET_CURRENT_CACHED_VALUES(3);
stack_pointer += -2;
ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
assert(WITHIN_STACK_BOUNDS_IGNORING_CACHE());
break;
}
case _FOR_ITER_GEN_FRAME_r13: {
CHECK_CURRENT_CACHED_VALUES(1);
assert(WITHIN_STACK_BOUNDS_IGNORING_CACHE());
_PyStackRef iter;
_PyStackRef gen_frame;
_PyStackRef _stack_item_0 = _tos_cache0;
oparg = CURRENT_OPARG();
iter = stack_pointer[-1];
PyGenObject *gen = (PyGenObject *)PyStackRef_AsPyObjectBorrow(iter);
if (Py_TYPE(gen) != &PyGen_Type) {
UOP_STAT_INC(uopcode, miss);
_tos_cache0 = _stack_item_0;
SET_CURRENT_CACHED_VALUES(1);
JUMP_TO_JUMP_TARGET();
}
if (!gen_try_set_executing((PyGenObject *)gen)) {
UOP_STAT_INC(uopcode, miss);
_tos_cache0 = _stack_item_0;
SET_CURRENT_CACHED_VALUES(1);
JUMP_TO_JUMP_TARGET();
}
STAT_INC(FOR_ITER, hit);
_PyInterpreterFrame *pushed_frame = &gen->gi_iframe;
_PyFrame_StackPush(pushed_frame, PyStackRef_None);
gen->gi_exc_state.previous_item = tstate->exc_info;
tstate->exc_info = &gen->gi_exc_state;
pushed_frame->previous = frame;
frame->return_offset = (uint16_t)( 2u + oparg);
gen_frame = PyStackRef_Wrap(pushed_frame);
_tos_cache2 = gen_frame;
_tos_cache1 = _stack_item_0;
_tos_cache0 = iter;
SET_CURRENT_CACHED_VALUES(3);
stack_pointer += -1;
ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
assert(WITHIN_STACK_BOUNDS_IGNORING_CACHE());
break;
}
case _FOR_ITER_GEN_FRAME_r23: {
CHECK_CURRENT_CACHED_VALUES(2);
assert(WITHIN_STACK_BOUNDS_IGNORING_CACHE());
@ -10876,17 +10951,7 @@
SET_CURRENT_CACHED_VALUES(2);
JUMP_TO_JUMP_TARGET();
}
#ifdef Py_GIL_DISABLED
if (!_PyObject_IsUniquelyReferenced((PyObject *)gen)) {
UOP_STAT_INC(uopcode, miss);
_tos_cache1 = _stack_item_1;
_tos_cache0 = iter;
SET_CURRENT_CACHED_VALUES(2);
JUMP_TO_JUMP_TARGET();
}
#endif
if (gen->gi_frame_state >= FRAME_EXECUTING) {
if (!gen_try_set_executing((PyGenObject *)gen)) {
UOP_STAT_INC(uopcode, miss);
_tos_cache1 = _stack_item_1;
_tos_cache0 = iter;
@ -10896,7 +10961,6 @@
STAT_INC(FOR_ITER, hit);
_PyInterpreterFrame *pushed_frame = &gen->gi_iframe;
_PyFrame_StackPush(pushed_frame, PyStackRef_None);
gen->gi_frame_state = FRAME_EXECUTING;
gen->gi_exc_state.previous_item = tstate->exc_info;
tstate->exc_info = &gen->gi_exc_state;
pushed_frame->previous = frame;