diff options
Diffstat (limited to 'Python/pystate.c')
-rw-r--r-- | Python/pystate.c | 98 |
1 files changed, 46 insertions, 52 deletions
diff --git a/Python/pystate.c b/Python/pystate.c index 44f55be..975eb6d 100644 --- a/Python/pystate.c +++ b/Python/pystate.c @@ -790,18 +790,15 @@ interpreter_clear(PyInterpreterState *interp, PyThreadState *tstate) } // Clear the current/main thread state last. - HEAD_LOCK(runtime); - PyThreadState *p = interp->threads.head; - HEAD_UNLOCK(runtime); - while (p != NULL) { + _Py_FOR_EACH_TSTATE_BEGIN(interp, p) { // See https://github.com/python/cpython/issues/102126 // Must be called without HEAD_LOCK held as it can deadlock // if any finalizer tries to acquire that lock. + HEAD_UNLOCK(runtime); PyThreadState_Clear(p); HEAD_LOCK(runtime); - p = p->next; - HEAD_UNLOCK(runtime); } + _Py_FOR_EACH_TSTATE_END(interp); if (tstate->interp == interp) { /* We fix tstate->_status below when we for sure aren't using it (e.g. no longer need the GIL). */ @@ -1801,10 +1798,9 @@ tstate_delete_common(PyThreadState *tstate, int release_gil) static void zapthreads(PyInterpreterState *interp) { - PyThreadState *tstate; /* No need to lock the mutex here because this should only happen when the threads are all really dead (XXX famous last words). */ - while ((tstate = interp->threads.head) != NULL) { + _Py_FOR_EACH_TSTATE_UNLOCKED(interp, tstate) { tstate_verify_not_active(tstate); tstate_delete_common(tstate, 0); free_threadstate((_PyThreadStateImpl *)tstate); @@ -2161,7 +2157,7 @@ decrement_stoptheworld_countdown(struct _stoptheworld_state *stw) } #ifdef Py_GIL_DISABLED -// Interpreter for _Py_FOR_EACH_THREAD(). For global stop-the-world events, +// Interpreter for _Py_FOR_EACH_STW_INTERP(). For global stop-the-world events, // we start with the first interpreter and then iterate over all interpreters. // For per-interpreter stop-the-world events, we only operate on the one // interpreter. @@ -2176,10 +2172,9 @@ interp_for_stop_the_world(struct _stoptheworld_state *stw) // Loops over threads for a stop-the-world event. // For global: all threads in all interpreters // For per-interpreter: all threads in the interpreter -#define _Py_FOR_EACH_THREAD(stw, i, t) \ - for (i = interp_for_stop_the_world((stw)); \ - i != NULL; i = ((stw->is_global) ? i->next : NULL)) \ - for (t = i->threads.head; t; t = t->next) +#define _Py_FOR_EACH_STW_INTERP(stw, i) \ + for (PyInterpreterState *i = interp_for_stop_the_world((stw)); \ + i != NULL; i = ((stw->is_global) ? i->next : NULL)) // Try to transition threads atomically from the "detached" state to the @@ -2188,19 +2183,19 @@ static bool park_detached_threads(struct _stoptheworld_state *stw) { int num_parked = 0; - PyInterpreterState *i; - PyThreadState *t; - _Py_FOR_EACH_THREAD(stw, i, t) { - int state = _Py_atomic_load_int_relaxed(&t->state); - if (state == _Py_THREAD_DETACHED) { - // Atomically transition to "suspended" if in "detached" state. - if (_Py_atomic_compare_exchange_int(&t->state, - &state, _Py_THREAD_SUSPENDED)) { - num_parked++; + _Py_FOR_EACH_STW_INTERP(stw, i) { + _Py_FOR_EACH_TSTATE_UNLOCKED(i, t) { + int state = _Py_atomic_load_int_relaxed(&t->state); + if (state == _Py_THREAD_DETACHED) { + // Atomically transition to "suspended" if in "detached" state. + if (_Py_atomic_compare_exchange_int( + &t->state, &state, _Py_THREAD_SUSPENDED)) { + num_parked++; + } + } + else if (state == _Py_THREAD_ATTACHED && t != stw->requester) { + _Py_set_eval_breaker_bit(t, _PY_EVAL_PLEASE_STOP_BIT); } - } - else if (state == _Py_THREAD_ATTACHED && t != stw->requester) { - _Py_set_eval_breaker_bit(t, _PY_EVAL_PLEASE_STOP_BIT); } } stw->thread_countdown -= num_parked; @@ -2227,12 +2222,12 @@ stop_the_world(struct _stoptheworld_state *stw) stw->stop_event = (PyEvent){0}; // zero-initialize (unset) stw->requester = _PyThreadState_GET(); // may be NULL - PyInterpreterState *i; - PyThreadState *t; - _Py_FOR_EACH_THREAD(stw, i, t) { - if (t != stw->requester) { - // Count all the other threads (we don't wait on ourself). - stw->thread_countdown++; + _Py_FOR_EACH_STW_INTERP(stw, i) { + _Py_FOR_EACH_TSTATE_UNLOCKED(i, t) { + if (t != stw->requester) { + // Count all the other threads (we don't wait on ourself). + stw->thread_countdown++; + } } } @@ -2273,14 +2268,14 @@ start_the_world(struct _stoptheworld_state *stw) stw->requested = 0; stw->world_stopped = 0; // Switch threads back to the detached state. - PyInterpreterState *i; - PyThreadState *t; - _Py_FOR_EACH_THREAD(stw, i, t) { - if (t != stw->requester) { - assert(_Py_atomic_load_int_relaxed(&t->state) == - _Py_THREAD_SUSPENDED); - _Py_atomic_store_int(&t->state, _Py_THREAD_DETACHED); - _PyParkingLot_UnparkAll(&t->state); + _Py_FOR_EACH_STW_INTERP(stw, i) { + _Py_FOR_EACH_TSTATE_UNLOCKED(i, t) { + if (t != stw->requester) { + assert(_Py_atomic_load_int_relaxed(&t->state) == + _Py_THREAD_SUSPENDED); + _Py_atomic_store_int(&t->state, _Py_THREAD_DETACHED); + _PyParkingLot_UnparkAll(&t->state); + } } } stw->requester = NULL; @@ -2344,7 +2339,6 @@ _PyEval_StartTheWorld(PyInterpreterState *interp) int PyThreadState_SetAsyncExc(unsigned long id, PyObject *exc) { - _PyRuntimeState *runtime = &_PyRuntime; PyInterpreterState *interp = _PyInterpreterState_GET(); /* Although the GIL is held, a few C API functions can be called @@ -2353,12 +2347,16 @@ PyThreadState_SetAsyncExc(unsigned long id, PyObject *exc) * list of thread states we're traversing, so to prevent that we lock * head_mutex for the duration. */ - HEAD_LOCK(runtime); - for (PyThreadState *tstate = interp->threads.head; tstate != NULL; tstate = tstate->next) { - if (tstate->thread_id != id) { - continue; + PyThreadState *tstate = NULL; + _Py_FOR_EACH_TSTATE_BEGIN(interp, t) { + if (t->thread_id == id) { + tstate = t; + break; } + } + _Py_FOR_EACH_TSTATE_END(interp); + if (tstate != NULL) { /* Tricky: we need to decref the current value * (if any) in tstate->async_exc, but that can in turn * allow arbitrary Python code to run, including @@ -2368,14 +2366,12 @@ PyThreadState_SetAsyncExc(unsigned long id, PyObject *exc) */ Py_XINCREF(exc); PyObject *old_exc = _Py_atomic_exchange_ptr(&tstate->async_exc, exc); - HEAD_UNLOCK(runtime); Py_XDECREF(old_exc); _Py_set_eval_breaker_bit(tstate, _PY_ASYNC_EXCEPTION_BIT); - return 1; } - HEAD_UNLOCK(runtime); - return 0; + + return tstate != NULL; } //--------------------------------- @@ -2515,8 +2511,7 @@ _PyThread_CurrentFrames(void) HEAD_LOCK(runtime); PyInterpreterState *i; for (i = runtime->interpreters.head; i != NULL; i = i->next) { - PyThreadState *t; - for (t = i->threads.head; t != NULL; t = t->next) { + _Py_FOR_EACH_TSTATE_UNLOCKED(i, t) { _PyInterpreterFrame *frame = t->current_frame; frame = _PyFrame_GetFirstComplete(frame); if (frame == NULL) { @@ -2581,8 +2576,7 @@ _PyThread_CurrentExceptions(void) HEAD_LOCK(runtime); PyInterpreterState *i; for (i = runtime->interpreters.head; i != NULL; i = i->next) { - PyThreadState *t; - for (t = i->threads.head; t != NULL; t = t->next) { + _Py_FOR_EACH_TSTATE_UNLOCKED(i, t) { _PyErr_StackItem *err_info = _PyErr_GetTopmostException(t); if (err_info == NULL) { continue; |