gh-115942: Add locked to several multiprocessing locks

Lib/multiprocessing/managers.py

@@ -1051,20 +1051,22 @@ def close(self, *args):
 
 
 class AcquirerProxy(BaseProxy):
-    _exposed_ = ('acquire', 'release')
+    _exposed_ = ('acquire', 'release', 'locked')
     def acquire(self, blocking=True, timeout=None):
         args = (blocking,) if timeout is None else (blocking, timeout)
         return self._callmethod('acquire', args)
     def release(self):
         return self._callmethod('release')
+    def locked(self):
+        return self._callmethod('locked')
     def __enter__(self):
         return self._callmethod('acquire')
     def __exit__(self, exc_type, exc_val, exc_tb):
         return self._callmethod('release')
 
 
 class ConditionProxy(AcquirerProxy):
-    _exposed_ = ('acquire', 'release', 'wait', 'notify', 'notify_all')
+    _exposed_ = ('acquire', 'release', 'locked', 'wait', 'notify', 'notify_all')
     def wait(self, timeout=None):
         return self._callmethod('wait', (timeout,))
     def notify(self, n=1):

Lib/multiprocessing/synchronize.py

@@ -91,6 +91,9 @@ def _make_methods(self):
         self.acquire = self._semlock.acquire
         self.release = self._semlock.release
 
+    def locked(self):
+        return self._semlock._count() != 0
+
     def __enter__(self):
         return self._semlock.__enter__()
 

Lib/test/_test_multiprocessing.py

@@ -1348,23 +1348,32 @@ class _TestLock(BaseTestCase):
     def test_lock(self):
         lock = self.Lock()
         self.assertEqual(lock.acquire(), True)
+        self.assertEqual(lock.locked(), True)
         self.assertEqual(lock.acquire(False), False)
         self.assertEqual(lock.release(), None)
+        self.assertFalse(lock.locked())
         self.assertRaises((ValueError, threading.ThreadError), lock.release)
 
     def test_rlock(self):
         lock = self.RLock()
         self.assertEqual(lock.acquire(), True)
+        self.assertTrue(lock.locked())
         self.assertEqual(lock.acquire(), True)
         self.assertEqual(lock.acquire(), True)
         self.assertEqual(lock.release(), None)
+        self.assertTrue(lock.locked())
         self.assertEqual(lock.release(), None)
         self.assertEqual(lock.release(), None)
+        self.assertFalse(lock.locked())
         self.assertRaises((AssertionError, RuntimeError), lock.release)
 
     def test_lock_context(self):
-        with self.Lock():
-            pass
+        with self.Lock() as locked:
+            self.assertTrue(locked)
+
+    def test_rlock_context(self):
+        with self.RLock() as locked:
+            self.assertTrue(locked)
 
 
 class _TestSemaphore(BaseTestCase):

Modules/_threadmodule.c

@@ -578,6 +578,17 @@ Do note that if the lock was acquire()d several times in a row by the\n\
 current thread, release() needs to be called as many times for the lock\n\
 to be available for other threads.");
 
+static PyObject *
+rlock_locked(rlockobject *self, PyObject *Py_UNUSED(ignored))
+{
+    return PyBool_FromLong(self->rlock_count);
+}
+
+PyDoc_STRVAR(rlock_locked_doc,
+"locked()\n\
+\n\
+Returns whether this lock is locked right now or not.");
+
 static PyObject *
 rlock_acquire_restore(rlockobject *self, PyObject *args)
 {
@@ -719,6 +730,8 @@ static PyMethodDef rlock_methods[] = {
      METH_VARARGS | METH_KEYWORDS, rlock_acquire_doc},
     {"release",      (PyCFunction)rlock_release,
      METH_NOARGS, rlock_release_doc},
+    {"locked",       (PyCFunction)rlock_locked,
+     METH_NOARGS, rlock_locked_doc},
     {"_is_owned",     (PyCFunction)rlock_is_owned,
      METH_NOARGS, rlock_is_owned_doc},
     {"_acquire_restore", (PyCFunction)rlock_acquire_restore,