From fc9ea97a18c2c25045b4cc993932702b30df239c Mon Sep 17 00:00:00 2001 From: Georg Brandl Date: Sun, 15 Mar 2009 22:11:07 +0000 Subject: Move the previously local import of threading to module level. This is cleaner and avoids lockups in obscure cases where a Queue is instantiated while the import lock is already held by another thread. OKed by Tim Peters. --- Lib/Queue.py | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/Lib/Queue.py b/Lib/Queue.py index 773b680..2db8d76 100644 --- a/Lib/Queue.py +++ b/Lib/Queue.py @@ -1,6 +1,10 @@ """A multi-producer, multi-consumer queue.""" from time import time as _time +try: + import threading as _threading +except ImportError: + import dummy_threading as _threading from collections import deque import heapq @@ -20,26 +24,22 @@ class Queue: If maxsize is <= 0, the queue size is infinite. """ def __init__(self, maxsize=0): - try: - import threading - except ImportError: - import dummy_threading as threading self.maxsize = maxsize self._init(maxsize) # mutex must be held whenever the queue is mutating. All methods # that acquire mutex must release it before returning. mutex # is shared between the three conditions, so acquiring and # releasing the conditions also acquires and releases mutex. - self.mutex = threading.Lock() + self.mutex = _threading.Lock() # Notify not_empty whenever an item is added to the queue; a # thread waiting to get is notified then. - self.not_empty = threading.Condition(self.mutex) + self.not_empty = _threading.Condition(self.mutex) # Notify not_full whenever an item is removed from the queue; # a thread waiting to put is notified then. - self.not_full = threading.Condition(self.mutex) + self.not_full = _threading.Condition(self.mutex) # Notify all_tasks_done whenever the number of unfinished tasks # drops to zero; thread waiting to join() is notified to resume - self.all_tasks_done = threading.Condition(self.mutex) + self.all_tasks_done = _threading.Condition(self.mutex) self.unfinished_tasks = 0 def task_done(self): -- cgit v0.12