gh-149399: Modify and add a representation strings for multiprocessing.[Barrier|Event]

Lib/multiprocessing/synchronize.py

@@ -369,7 +369,8 @@ def wait(self, timeout=None):
 
     def __repr__(self):
         set_status = 'set' if self.is_set() else 'unset'
-        return f"<{type(self).__qualname__} at {id(self):#x} {set_status}>"
+        return f"<{type(self).__qualname__}({set_status})>"
+
 #
 # Barrier
 #
@@ -409,3 +410,9 @@ def _count(self):
     @_count.setter
     def _count(self, value):
         self._array[1] = value
+
+    def __repr__(self):
+        name = self.__class__.__qualname__
+        if self.broken:
+            return f"<{name}(broken)>"
+        return (f"<{name}(waiters={self.n_waiting}/{self.parties})>")

Lib/test/_test_multiprocessing.py

@@ -2132,13 +2132,14 @@ def test_event(self):
         p.join()
 
     def test_repr(self) -> None:
+        # Change repr, see gh-149399.
         event = self.Event()
         if self.TYPE == 'processes':
-            self.assertRegex(repr(event), r"<Event at .* unset>")
+            self.assertIn("<Event(unset)>", repr(event))
             event.set()
-            self.assertRegex(repr(event), r"<Event at .* set>")
+            self.assertIn("<Event(set)>", repr(event))
             event.clear()
-            self.assertRegex(repr(event), r"<Event at .* unset>")
+            self.assertIn("<Event(unset)>", repr(event))
         elif self.TYPE == 'manager':
             self.assertRegex(repr(event), r"<EventProxy object, typeid 'Event' at .*")
             event.set()
@@ -2505,6 +2506,19 @@ def test_thousand(self):
             for j in range(self.N):
                 self.assertEqual(conn.recv(), i)
 
+    def test_repr(self):
+        # Add repr, see gh-149399.
+        b = self.barrier
+        if self.TYPE == 'process':
+            self.assertIn(f"waiters=0/{self.N}", repr(b))
+            b.abort()
+            self.assertIn("broken", repr(b))
+            self.assertNotIn("at", repr(b))
+        elif self.TYPE == 'manager':
+            self.assertRegex(repr(b), r"<BarrierProxy object, typeid 'Barrier' at .*")
+            b.abort()
+            self.assertRegex(repr(b), r"<BarrierProxy object, typeid 'Barrier' at .*")
+
 #
 #
 #

Misc/NEWS.d/next/Library/2026-05-06-08-44-03.gh-issue-149399.zqSWNs.rst

@@ -0,0 +1 @@
+Change the ``__repr__`` of :class:`multiprocessing.Event` and add a ``__repr__`` method to the :class:`multiprocessing.Barrier` in order to be consistent with the other synchronization primitives of :mod:`multiprocessing` module.