Add _PyEval_RaiseAsyncExc; call it from PyErr_CheckSignals

Author: encukou

Include/internal/pycore_ceval.h

@@ -286,6 +286,9 @@ PyAPI_FUNC(PyObject *)_Py_MakeCoro(PyFunctionObject *func);
    and asynchronous exception */
 PyAPI_FUNC(int) _Py_HandlePending(PyThreadState *tstate);
 
+/* Raise exception set by PyThreadState_SetAsyncExc, if any */
+PyAPI_FUNC(int) _PyEval_RaiseAsyncExc(PyThreadState *tstate);
+
 extern PyObject * _PyEval_GetFrameLocals(void);
 
 typedef PyObject *(*conversion_func)(PyObject *);

Modules/signalmodule.c

@@ -1781,20 +1781,28 @@ PyErr_CheckSignals(void)
        Python code to ensure signals are handled. Checking for the GC here
        allows long running native code to clean cycles created using the C-API
        even if it doesn't run the evaluation loop */
-    if (_Py_eval_breaker_bit_is_set(tstate, _PY_GC_SCHEDULED_BIT)) {
+    uintptr_t breaker = _Py_atomic_load_uintptr_relaxed(&tstate->eval_breaker);
+    if (breaker & _PY_GC_SCHEDULED_BIT) {
         _Py_unset_eval_breaker_bit(tstate, _PY_GC_SCHEDULED_BIT);
         _Py_RunGC(tstate);
     }
+    if (breaker & _PY_ASYNC_EXCEPTION_BIT) {
+        if (_PyEval_RaiseAsyncExc(tstate) < 0) {
+            return -1;
+        }
+    }
 
 #if defined(Py_REMOTE_DEBUG) && defined(Py_SUPPORTS_REMOTE_DEBUG)
     _PyRunRemoteDebugger(tstate);
 #endif
 
-    if (!_Py_ThreadCanHandleSignals(tstate->interp)) {
-        return 0;
+    if (_Py_ThreadCanHandleSignals(tstate->interp)) {
+        if (_PyErr_CheckSignalsTstate(tstate) < 0) {
+            return -1;
+        }
     }
 
-    return _PyErr_CheckSignalsTstate(tstate);
+    return 0;
 }
 
 

Python/ceval_gil.c

@@ -1423,11 +1423,7 @@ _Py_HandlePending(PyThreadState *tstate)
 
     /* Check for asynchronous exception. */
     if ((breaker & _PY_ASYNC_EXCEPTION_BIT) != 0) {
-        _Py_unset_eval_breaker_bit(tstate, _PY_ASYNC_EXCEPTION_BIT);
-        PyObject *exc = _Py_atomic_exchange_ptr(&tstate->async_exc, NULL);
-        if (exc != NULL) {
-            _PyErr_SetNone(tstate, exc);
-            Py_DECREF(exc);
+        if (_PyEval_RaiseAsyncExc(tstate) < 0) {
             return -1;
         }
     }
@@ -1438,3 +1434,16 @@ _Py_HandlePending(PyThreadState *tstate)
 
     return 0;
 }
+
+int
+_PyEval_RaiseAsyncExc(PyThreadState *tstate)
+{
+    _Py_unset_eval_breaker_bit(tstate, _PY_ASYNC_EXCEPTION_BIT);
+    PyObject *exc = _Py_atomic_exchange_ptr(&tstate->async_exc, NULL);
+    if (exc != NULL) {
+        _PyErr_SetNone(tstate, exc);
+        Py_DECREF(exc);
+        return -1;
+    }
+    return 0;
+}