gh-87063: Add closed attribute to multiprocessing.Process

Lib/multiprocessing/process.py

@@ -169,6 +169,12 @@ def is_alive(self):
             _children.discard(self)
             return False
 
+    def is_closed(self):
+        '''
+        Return whether process is closed
+        '''
+        return self._closed
+
     def close(self):
         '''
         Close the Process object.

Lib/test/_test_multiprocessing.py

@@ -649,6 +649,21 @@ def _test_close(cls, rc=0, q=None):
             q.get()
         sys.exit(rc)
 
+    def test_is_close(self):
+        if self.TYPE == "threads":
+            self.skipTest('test not appropriate for {}'.format(self.TYPE))
+        q = self.Queue()
+        p = self.Process(target=self._test_close, kwargs={'q': q})
+        self.assertFalse(p.is_closed())
+        p.close()
+        self.assertTrue(p.is_closed())
+
+        wr = weakref.ref(p)
+        del p
+        gc.collect()
+        self.assertIs(wr(), None)
+        close_queue(q)
+
     def test_close(self):
         if self.TYPE == "threads":
             self.skipTest('test not appropriate for {}'.format(self.TYPE))

Misc/NEWS.d/next/Library/2024-10-22-19-52-15.gh-issue-87063.fR-wJa.rst

@@ -0,0 +1,2 @@
+Add the :meth:`.is_closed()` in the :class:`multiprocessing.Process` to
+determine whether the process is closed.