diff options
Diffstat (limited to 'Python')
| -rw-r--r-- | Python/ceval.c | 10 | ||||
| -rw-r--r-- | Python/gc.c | 25 | ||||
| -rw-r--r-- | Python/gc_free_threading.c | 20 | ||||
| -rw-r--r-- | Python/initconfig.c | 2 | ||||
| -rw-r--r-- | Python/pylifecycle.c | 14 |
5 files changed, 52 insertions, 19 deletions
diff --git a/Python/ceval.c b/Python/ceval.c index 50665defd38..291e753dec0 100644 --- a/Python/ceval.c +++ b/Python/ceval.c @@ -627,12 +627,14 @@ _PyEval_MatchKeys(PyThreadState *tstate, PyObject *map, PyObject *keys) PyObject *seen = NULL; PyObject *dummy = NULL; PyObject *values = NULL; - PyObject *get = NULL; // We use the two argument form of map.get(key, default) for two reasons: // - Atomically check for a key and get its value without error handling. // - Don't cause key creation or resizing in dict subclasses like // collections.defaultdict that define __missing__ (or similar). - int meth_found = _PyObject_GetMethod(map, &_Py_ID(get), &get); + _PyCStackRef cref; + _PyThreadState_PushCStackRef(tstate, &cref); + int meth_found = _PyObject_GetMethodStackRef(tstate, map, &_Py_ID(get), &cref.ref); + PyObject *get = PyStackRef_AsPyObjectBorrow(cref.ref); if (get == NULL) { goto fail; } @@ -682,12 +684,12 @@ _PyEval_MatchKeys(PyThreadState *tstate, PyObject *map, PyObject *keys) } // Success: done: - Py_DECREF(get); + _PyThreadState_PopCStackRef(tstate, &cref); Py_DECREF(seen); Py_DECREF(dummy); return values; fail: - Py_XDECREF(get); + _PyThreadState_PopCStackRef(tstate, &cref); Py_XDECREF(seen); Py_XDECREF(dummy); Py_XDECREF(values); diff --git a/Python/gc.c b/Python/gc.c index 02135a3fb44..88849a43680 100644 --- a/Python/gc.c +++ b/Python/gc.c @@ -870,7 +870,7 @@ move_legacy_finalizer_reachable(PyGC_Head *finalizers) * no object in `unreachable` is weakly referenced anymore. */ static int -handle_weakrefs(PyGC_Head *unreachable, PyGC_Head *old) +handle_weakrefs(PyGC_Head *unreachable, PyGC_Head *old, bool allow_callbacks) { PyGC_Head *gc; PyObject *op; /* generally FROM_GC(gc) */ @@ -879,7 +879,9 @@ handle_weakrefs(PyGC_Head *unreachable, PyGC_Head *old) PyGC_Head *next; int num_freed = 0; - gc_list_init(&wrcb_to_call); + if (allow_callbacks) { + gc_list_init(&wrcb_to_call); + } /* Clear all weakrefs to the objects in unreachable. If such a weakref * also has a callback, move it into `wrcb_to_call` if the callback @@ -935,6 +937,11 @@ handle_weakrefs(PyGC_Head *unreachable, PyGC_Head *old) _PyObject_ASSERT((PyObject *)wr, wr->wr_object == op); _PyWeakref_ClearRef(wr); _PyObject_ASSERT((PyObject *)wr, wr->wr_object == Py_None); + + if (!allow_callbacks) { + continue; + } + if (wr->wr_callback == NULL) { /* no callback */ continue; @@ -987,6 +994,10 @@ handle_weakrefs(PyGC_Head *unreachable, PyGC_Head *old) } } + if (!allow_callbacks) { + return 0; + } + /* Invoke the callbacks we decided to honor. It's safe to invoke them * because they can't reference unreachable objects. */ @@ -1737,7 +1748,7 @@ gc_collect_region(PyThreadState *tstate, } /* Clear weakrefs and invoke callbacks as necessary. */ - stats->collected += handle_weakrefs(&unreachable, to); + stats->collected += handle_weakrefs(&unreachable, to, true); gc_list_validate_space(to, gcstate->visited_space); validate_list(to, collecting_clear_unreachable_clear); validate_list(&unreachable, collecting_set_unreachable_clear); @@ -1751,6 +1762,14 @@ gc_collect_region(PyThreadState *tstate, gc_list_init(&final_unreachable); handle_resurrected_objects(&unreachable, &final_unreachable, to); + /* Clear weakrefs to objects in the unreachable set. No Python-level + * code must be allowed to access those unreachable objects. During + * delete_garbage(), finalizers outside the unreachable set might run + * and create new weakrefs. If those weakrefs were not cleared, they + * could reveal unreachable objects. Callbacks are not executed. + */ + handle_weakrefs(&final_unreachable, NULL, false); + /* Call tp_clear on objects in the final_unreachable set. This will cause * the reference cycles to be broken. It may also cause some objects * in finalizers to be freed. diff --git a/Python/gc_free_threading.c b/Python/gc_free_threading.c index 5aaa68c5b51..d46598b23b3 100644 --- a/Python/gc_free_threading.c +++ b/Python/gc_free_threading.c @@ -1492,9 +1492,9 @@ move_legacy_finalizer_reachable(struct collection_state *state) } // Clear all weakrefs to unreachable objects. Weakrefs with callbacks are -// enqueued in `wrcb_to_call`, but not invoked yet. +// optionally enqueued in `wrcb_to_call`, but not invoked yet. static void -clear_weakrefs(struct collection_state *state) +clear_weakrefs(struct collection_state *state, bool enqueue_callbacks) { PyObject *op; WORKSTACK_FOR_EACH(&state->unreachable, op) { @@ -1526,6 +1526,10 @@ clear_weakrefs(struct collection_state *state) _PyWeakref_ClearRef(wr); _PyObject_ASSERT((PyObject *)wr, wr->wr_object == Py_None); + if (!enqueue_callbacks) { + continue; + } + // We do not invoke callbacks for weakrefs that are themselves // unreachable. This is partly for historical reasons: weakrefs // predate safe object finalization, and a weakref that is itself @@ -2211,7 +2215,7 @@ gc_collect_internal(PyInterpreterState *interp, struct collection_state *state, interp->gc.long_lived_total = state->long_lived_total; // Clear weakrefs and enqueue callbacks (but do not call them). - clear_weakrefs(state); + clear_weakrefs(state, true); _PyEval_StartTheWorld(interp); // Deallocate any object from the refcount merge step @@ -2222,11 +2226,19 @@ gc_collect_internal(PyInterpreterState *interp, struct collection_state *state, call_weakref_callbacks(state); finalize_garbage(state); - // Handle any objects that may have resurrected after the finalization. _PyEval_StopTheWorld(interp); + // Handle any objects that may have resurrected after the finalization. err = handle_resurrected_objects(state); // Clear free lists in all threads _PyGC_ClearAllFreeLists(interp); + if (err == 0) { + // Clear weakrefs to objects in the unreachable set. No Python-level + // code must be allowed to access those unreachable objects. During + // delete_garbage(), finalizers outside the unreachable set might + // run and create new weakrefs. If those weakrefs were not cleared, + // they could reveal unreachable objects. + clear_weakrefs(state, false); + } _PyEval_StartTheWorld(interp); if (err < 0) { diff --git a/Python/initconfig.c b/Python/initconfig.c index 71d7cfed5c4..73a9a9bf1ca 100644 --- a/Python/initconfig.c +++ b/Python/initconfig.c @@ -312,7 +312,7 @@ The following implementation-specific options are available:\n\ "-X gil=[0|1]: enable (1) or disable (0) the GIL; also PYTHON_GIL\n" #endif "\ --X importtime[=2]: show how long each import takes; use -X importtime=2 to\ +-X importtime[=2]: show how long each import takes; use -X importtime=2 to\n\ log imports of already-loaded modules; also PYTHONPROFILEIMPORTTIME\n\ -X int_max_str_digits=N: limit the size of int<->str conversions;\n\ 0 disables the limit; also PYTHONINTMAXSTRDIGITS\n\ diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c index 724fda63511..00e8d030765 100644 --- a/Python/pylifecycle.c +++ b/Python/pylifecycle.c @@ -1702,8 +1702,10 @@ finalize_modules(PyThreadState *tstate) #endif // Stop watching __builtin__ modifications - PyDict_Unwatch(0, interp->builtins); - + if (PyDict_Unwatch(0, interp->builtins) < 0) { + // might happen if interp is cleared before watching the __builtin__ + PyErr_Clear(); + } PyObject *modules = _PyImport_GetModules(interp); if (modules == NULL) { // Already done @@ -2377,15 +2379,13 @@ new_interpreter(PyThreadState **tstate_p, error: *tstate_p = NULL; if (tstate != NULL) { - PyThreadState_Clear(tstate); - _PyThreadState_Detach(tstate); - PyThreadState_Delete(tstate); + Py_EndInterpreter(tstate); + } else { + PyInterpreterState_Delete(interp); } if (save_tstate != NULL) { _PyThreadState_Attach(save_tstate); } - PyInterpreterState_Delete(interp); - return status; } |