fixup! pythongh-127124: Pass optional state to context watcher callback

Author: rhansen

Lib/test/test_capi/test_watchers.py

@@ -1,3 +1,4 @@
+import contextlib
 import unittest
 import contextvars
 
@@ -639,16 +640,19 @@ def _in_outer():
     def test_clear_out_of_range_watcher_id(self):
         with self.assertRaisesRegex(ValueError, r"Invalid context watcher ID -1"):
             _testcapi.clear_context_watcher(-1)
-        with self.assertRaisesRegex(ValueError, r"Invalid context watcher ID 8"):
-            _testcapi.clear_context_watcher(8)  # CONTEXT_MAX_WATCHERS = 8
+        with self.assertRaisesRegex(ValueError, f"Invalid context watcher ID {_testcapi.CONTEXT_MAX_WATCHERS}"):
+            _testcapi.clear_context_watcher(_testcapi.CONTEXT_MAX_WATCHERS)
 
     def test_clear_unassigned_watcher_id(self):
         with self.assertRaisesRegex(ValueError, r"No context watcher set for ID 1"):
             _testcapi.clear_context_watcher(1)
 
     def test_allocate_too_many_watchers(self):
-        with self.assertRaisesRegex(RuntimeError, r"no more context watcher IDs available"):
-            _testcapi.allocate_too_many_context_watchers()
+        with contextlib.ExitStack() as stack:
+            for i in range(_testcapi.CONTEXT_MAX_WATCHERS):
+                stack.enter_context(self.context_watcher())
+            with self.assertRaisesRegex(RuntimeError, r"no more context watcher IDs available"):
+                stack.enter_context(self.context_watcher())
 
     def test_exit_base_context(self):
         ctx = contextvars.Context()

Modules/_testcapi/watchers.c

@@ -710,36 +710,6 @@ clear_context_stack(PyObject *Py_UNUSED(self), PyObject *Py_UNUSED(args))
     Py_RETURN_NONE;
 }
 
-static PyObject *
-allocate_too_many_context_watchers(PyObject *self, PyObject *args)
-{
-    int watcher_ids[CONTEXT_MAX_WATCHERS + 1];
-    int num_watchers = 0;
-    for (unsigned long i = 0; i < sizeof(watcher_ids) / sizeof(int); i++) {
-        int watcher_id = PyContext_AddWatcher(&context_watcher, NULL);
-        if (watcher_id == -1) {
-            break;
-        }
-        watcher_ids[i] = watcher_id;
-        num_watchers++;
-    }
-    PyObject *exc = PyErr_GetRaisedException();
-    for (int i = 0; i < num_watchers; i++) {
-        if (PyContext_ClearWatcher(watcher_ids[i]) < 0) {
-            PyErr_WriteUnraisable(Py_None);
-            break;
-        }
-    }
-    if (exc) {
-        PyErr_SetRaisedException(exc);
-        return NULL;
-    }
-    else if (PyErr_Occurred()) {
-        return NULL;
-    }
-    Py_RETURN_NONE;
-}
-
 /*[clinic input]
 _testcapi.set_func_defaults_via_capi
     func: object
@@ -812,8 +782,6 @@ static PyMethodDef test_methods[] = {
     _TESTCAPI_ADD_CONTEXT_WATCHER_METHODDEF
     _TESTCAPI_CLEAR_CONTEXT_WATCHER_METHODDEF
     {"clear_context_stack",      clear_context_stack,     METH_NOARGS,  NULL},
-    {"allocate_too_many_context_watchers",
-     (PyCFunction) allocate_too_many_context_watchers,       METH_NOARGS,  NULL},
     {NULL},
 };
 
@@ -824,6 +792,16 @@ _PyTestCapi_Init_Watchers(PyObject *mod)
         return -1;
     }
 
+#define ADD_INT_CONST(INT)                                      \
+    do {                                                        \
+        if (PyModule_AddIntConstant(mod, #INT, INT) < 0) {      \
+            return -1;                                          \
+        }                                                       \
+    } while(0)
+    ADD_INT_CONST(CONTEXT_MAX_WATCHERS);
+    ADD_INT_CONST(Py_CONTEXT_SWITCHED);
+#undef ADD_INT_CONST
+
     /* Expose each event as an attribute on the module */
 #define ADD_EVENT(event)  \
     if (add_func_event(mod, "PYFUNC_EVENT_" #event,   \