Mailing List Archive

https://github.com/python/cpython/commit/6bc0b33a91713ee62fd1860d28b19cb620c45971
commit: 6bc0b33a91713ee62fd1860d28b19cb620c45971
branch: main
author: Laurie O <laurie_opperman@hotmail.com>
committer: gvanrossum <gvanrossum@gmail.com>
date: 2024-04-10T08:01:42-07:00
summary:

gh-117531: Unblock getters after non-immediate queue shutdown (#117532)

(This is a small tweak of the original gh-104750 which added shutdown.)

files:
M Doc/library/queue.rst
M Lib/queue.py
M Lib/test/test_queue.py

diff --git a/Doc/library/queue.rst b/Doc/library/queue.rst
index f2a6dbf589fd87..fce23313c7de28 100644
--- a/Doc/library/queue.rst
+++ b/Doc/library/queue.rst
@@ -245,8 +245,10 @@ them down.
queue is empty. Set *immediate* to true to make :meth:`~Queue.get` raise
immediately instead.

- All blocked callers of :meth:`~Queue.put` will be unblocked. If *immediate*
- is true, also unblock callers of :meth:`~Queue.get` and :meth:`~Queue.join`.
+ All blocked callers of :meth:`~Queue.put` and :meth:`~Queue.get` will be
+ unblocked. If *immediate* is true, a task will be marked as done for each
+ remaining item in the queue, which may unblock callers of
+ :meth:`~Queue.join`.

.. versionadded:: 3.13

diff --git a/Lib/queue.py b/Lib/queue.py
index 387ce5425879a4..25beb46e30d6bd 100644
--- a/Lib/queue.py
+++ b/Lib/queue.py
@@ -239,8 +239,9 @@ def shutdown(self, immediate=False):
By default, gets will only raise once the queue is empty. Set
'immediate' to True to make gets raise immediately instead.

- All blocked callers of put() will be unblocked, and also get()
- and join() if 'immediate'.
+ All blocked callers of put() and get() will be unblocked. If
+ 'immediate', a task is marked as done for each item remaining in
+ the queue, which may unblock callers of join().
'''
with self.mutex:
self.is_shutdown = True
@@ -249,9 +250,10 @@ def shutdown(self, immediate=False):
self._get()
if self.unfinished_tasks > 0:
self.unfinished_tasks -= 1
- self.not_empty.notify_all()
# release all blocked threads in `join()`
self.all_tasks_done.notify_all()
+ # All getters need to re-check queue-empty to raise ShutDown
+ self.not_empty.notify_all()
self.not_full.notify_all()

# Override these methods to implement other queue organizations
diff --git a/Lib/test/test_queue.py b/Lib/test/test_queue.py
index c4d10110132393..d5927fbf39142b 100644
--- a/Lib/test/test_queue.py
+++ b/Lib/test/test_queue.py
@@ -636,6 +636,23 @@ def test_shutdown_get_task_done_join(self):

self.assertEqual(results, [True]*len(thrds))

+ def test_shutdown_pending_get(self):
+ def get():
+ try:
+ results.append(q.get())
+ except Exception as e:
+ results.append(e)
+
+ q = self.type2test()
+ results = []
+ get_thread = threading.Thread(target=get)
+ get_thread.start()
+ q.shutdown(immediate=False)
+ get_thread.join(timeout=10.0)
+ self.assertFalse(get_thread.is_alive())
+ self.assertEqual(len(results), 1)
+ self.assertIsInstance(results[0], self.queue.ShutDown)
+

class QueueTest(BaseQueueTestMixin):


_______________________________________________
Python-checkins mailing list -- python-checkins@python.org
To unsubscribe send an email to python-checkins-leave@python.org
https://mail.python.org/mailman3/lists/python-checkins.python.org/
Member address: list-python-checkins@lists.gossamer-threads.com