From 189316a2e35eede0de61c4713777c2b8e04c2e99 Mon Sep 17 00:00:00 2001 From: Raymond Hettinger Date: Sun, 31 Oct 2010 17:57:52 +0000 Subject: Issue 10110: Let Queue.put recognize a full queue when the maxsize parameter has been reduced. --- Lib/queue.py | 10 +++++----- Lib/test/test_queue.py | 12 ++++++++++++ Misc/NEWS | 3 +++ 3 files changed, 20 insertions(+), 5 deletions(-) diff --git a/Lib/queue.py b/Lib/queue.py index f051f1c..bee7ed4 100644 --- a/Lib/queue.py +++ b/Lib/queue.py @@ -110,14 +110,14 @@ class Queue: def full(self): """Return True if the queue is full, False otherwise (not reliable!). - This method is likely to be removed at some point. Use qsize() == n + This method is likely to be removed at some point. Use qsize() >= n as a direct substitute, but be aware that either approach risks a race condition where a queue can shrink before the result of full() or qsize() can be used. """ self.mutex.acquire() - n = 0 < self.maxsize == self._qsize() + n = 0 < self.maxsize <= self._qsize() self.mutex.release() return n @@ -136,16 +136,16 @@ class Queue: try: if self.maxsize > 0: if not block: - if self._qsize() == self.maxsize: + if self._qsize() >= self.maxsize: raise Full elif timeout is None: - while self._qsize() == self.maxsize: + while self._qsize() >= self.maxsize: self.not_full.wait() elif timeout < 0: raise ValueError("'timeout' must be a positive number") else: endtime = _time() + timeout - while self._qsize() == self.maxsize: + while self._qsize() >= self.maxsize: remaining = endtime - _time() if remaining <= 0.0: raise Full diff --git a/Lib/test/test_queue.py b/Lib/test/test_queue.py index 0c8093a..5cef90c 100644 --- a/Lib/test/test_queue.py +++ b/Lib/test/test_queue.py @@ -216,6 +216,18 @@ class BaseQueueTest(unittest.TestCase, BlockingTestMixin): with self.assertRaises(queue.Empty): q.get_nowait() + def test_shrinking_queue(self): + # issue 10110 + q = self.type2test(3) + q.put(1) + q.put(2) + q.put(3) + with self.assertRaises(queue.Full): + q.put_nowait(4) + self.assertEqual(q.qsize(), 3) + q.maxsize = 2 # shrink the queue + with self.assertRaises(queue.Full): + q.put_nowait(4) class QueueTest(BaseQueueTest): type2test = queue.Queue diff --git a/Misc/NEWS b/Misc/NEWS index 5c0acfb..abb3ebc 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -62,6 +62,9 @@ Library - Issue #10266: uu.decode didn't close in_file explicitly when it was given as a filename. Patch by Brian Brazil. +- Issue #10110: Queue objects didn't recognize full queues when the + maxsize parameter had been reduced. + - Issue #10160: Speed up operator.attrgetter. Patch by Christos Georgiou. - logging: Added style option to basicConfig() to allow %, {} or $-formatting. -- cgit v0.12