some changes

isidentical · isidentical · commit 9f17cba72cb4 · 2020-03-15T14:09:48.000+03:00
diff --git a/Lib/multiprocessing/pool.py b/Lib/multiprocessing/pool.py
@@ -651,6 +651,8 @@ def close(self):
     def terminate(self):
         util.debug('terminating pool')
         self._state = TERMINATE
+        self._worker_handler._state = TERMINATE
+        self._change_notifier.put(None)
         self._terminate()
 
     def join(self):
@@ -680,8 +682,14 @@ def _terminate_pool(cls, taskqueue, inqueue, outqueue, pool, change_notifier,
         # this is guaranteed to only be called once
         util.debug('finalizing pool')
 
-        worker_handler._state = TERMINATE
-        change_notifier.put(None)
+        # Explicitly do the cleanup here if it didn't come from terminate()
+        # (required for if the queue will block, if it is already closed)
+        if worker_handler._state != TERMINATE:
+            # Notify that the worker_handler state has been changed so the
+            # _handle_workers loop can be unblocked (and exited) in order to
+            # send the finalization sentinel all the workers.
+            worker_handler._state = TERMINATE
+            change_notifier.put(None)
 
         task_handler._state = TERMINATE
 
diff --git a/Lib/test/_test_multiprocessing.py b/Lib/test/_test_multiprocessing.py
@@ -2780,7 +2780,7 @@ def test_pool_worker_lifetime_early_close(self):
         for (j, res) in enumerate(results):
             self.assertEqual(res.get(), sqr(j))
 
-    def test_pool_hang(self):
+    def test_worker_finalization_via_atexit_handler_of_multiprocessing(self):
         # tests cases against bpo-38744 and bpo-39360
         cmd = '''if 1:
             from multiprocessing import Pool
diff --git a/Misc/NEWS.d/next/Library/2020-03-15-05-41-05.bpo-39360.cmcU5p.rst b/Misc/NEWS.d/next/Library/2020-03-15-05-41-05.bpo-39360.cmcU5p.rst
@@ -1,3 +1,4 @@
 Ensure all workers exit when finalizing a :class:`multiprocessing.Pool` implicitly via the module finalization
 handlers of multiprocessing. This fixes a deadlock situation that can be experienced when the Pool is not
-properly finalized via the context manager or a call to ``multiprocessing.Pool.terminate``. Patch by Batuhan Taskaya.
+properly finalized via the context manager or a call to ``multiprocessing.Pool.terminate``. Patch by Batuhan Taskaya
+and Pablo Galindo.
