New submission from Raymond Hettinger: Condition variables implement a FIFO queue for waiting threads. The current implementation uses a regular Python list but could use a deque instead.
A wait() call appends a new waiter. A notify() call removes the oldest waiter; this is an O(n) operation on list but only an O(1) operation on deques. A notify_all() call is O(n**2) for a list but only O(n) for a deque. If there is interest in this patch, I can add slicing support to collections.deque so that this patch won't need itertools.islice() ---------- files: condition.diff keywords: patch messages: 183727 nosy: pitrou, rhettinger priority: normal severity: normal status: open title: Use deque instead of list the threading.Condition waiter queue type: performance versions: Python 3.4 Added file: http://bugs.python.org/file29348/condition.diff _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue17385> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com