--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/python-2.6.1/Lib/Queue.py Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,244 @@
+"""A multi-producer, multi-consumer queue."""
+
+from time import time as _time
+from collections import deque
+import heapq
+
+__all__ = ['Empty', 'Full', 'Queue', 'PriorityQueue', 'LifoQueue']
+
+class Empty(Exception):
+ "Exception raised by Queue.get(block=0)/get_nowait()."
+ pass
+
+class Full(Exception):
+ "Exception raised by Queue.put(block=0)/put_nowait()."
+ pass
+
+class Queue:
+ """Create a queue object with a given maximum size.
+
+ 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()
+ # 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)
+ # 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)
+ # 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.unfinished_tasks = 0
+
+ def task_done(self):
+ """Indicate that a formerly enqueued task is complete.
+
+ Used by Queue consumer threads. For each get() used to fetch a task,
+ a subsequent call to task_done() tells the queue that the processing
+ on the task is complete.
+
+ If a join() is currently blocking, it will resume when all items
+ have been processed (meaning that a task_done() call was received
+ for every item that had been put() into the queue).
+
+ Raises a ValueError if called more times than there were items
+ placed in the queue.
+ """
+ self.all_tasks_done.acquire()
+ try:
+ unfinished = self.unfinished_tasks - 1
+ if unfinished <= 0:
+ if unfinished < 0:
+ raise ValueError('task_done() called too many times')
+ self.all_tasks_done.notify_all()
+ self.unfinished_tasks = unfinished
+ finally:
+ self.all_tasks_done.release()
+
+ def join(self):
+ """Blocks until all items in the Queue have been gotten and processed.
+
+ The count of unfinished tasks goes up whenever an item is added to the
+ queue. The count goes down whenever a consumer thread calls task_done()
+ to indicate the item was retrieved and all work on it is complete.
+
+ When the count of unfinished tasks drops to zero, join() unblocks.
+ """
+ self.all_tasks_done.acquire()
+ try:
+ while self.unfinished_tasks:
+ self.all_tasks_done.wait()
+ finally:
+ self.all_tasks_done.release()
+
+ def qsize(self):
+ """Return the approximate size of the queue (not reliable!)."""
+ self.mutex.acquire()
+ n = self._qsize()
+ self.mutex.release()
+ return n
+
+ def empty(self):
+ """Return True if the queue is empty, False otherwise (not reliable!)."""
+ self.mutex.acquire()
+ n = not self._qsize()
+ self.mutex.release()
+ return n
+
+ def full(self):
+ """Return True if the queue is full, False otherwise (not reliable!)."""
+ self.mutex.acquire()
+ n = 0 < self.maxsize == self._qsize()
+ self.mutex.release()
+ return n
+
+ def put(self, item, block=True, timeout=None):
+ """Put an item into the queue.
+
+ If optional args 'block' is true and 'timeout' is None (the default),
+ block if necessary until a free slot is available. If 'timeout' is
+ a positive number, it blocks at most 'timeout' seconds and raises
+ the Full exception if no free slot was available within that time.
+ Otherwise ('block' is false), put an item on the queue if a free slot
+ is immediately available, else raise the Full exception ('timeout'
+ is ignored in that case).
+ """
+ self.not_full.acquire()
+ try:
+ if self.maxsize > 0:
+ if not block:
+ if self._qsize() == self.maxsize:
+ raise Full
+ elif timeout is None:
+ 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:
+ remaining = endtime - _time()
+ if remaining <= 0.0:
+ raise Full
+ self.not_full.wait(remaining)
+ self._put(item)
+ self.unfinished_tasks += 1
+ self.not_empty.notify()
+ finally:
+ self.not_full.release()
+
+ def put_nowait(self, item):
+ """Put an item into the queue without blocking.
+
+ Only enqueue the item if a free slot is immediately available.
+ Otherwise raise the Full exception.
+ """
+ return self.put(item, False)
+
+ def get(self, block=True, timeout=None):
+ """Remove and return an item from the queue.
+
+ If optional args 'block' is true and 'timeout' is None (the default),
+ block if necessary until an item is available. If 'timeout' is
+ a positive number, it blocks at most 'timeout' seconds and raises
+ the Empty exception if no item was available within that time.
+ Otherwise ('block' is false), return an item if one is immediately
+ available, else raise the Empty exception ('timeout' is ignored
+ in that case).
+ """
+ self.not_empty.acquire()
+ try:
+ if not block:
+ if not self._qsize():
+ raise Empty
+ elif timeout is None:
+ while not self._qsize():
+ self.not_empty.wait()
+ elif timeout < 0:
+ raise ValueError("'timeout' must be a positive number")
+ else:
+ endtime = _time() + timeout
+ while not self._qsize():
+ remaining = endtime - _time()
+ if remaining <= 0.0:
+ raise Empty
+ self.not_empty.wait(remaining)
+ item = self._get()
+ self.not_full.notify()
+ return item
+ finally:
+ self.not_empty.release()
+
+ def get_nowait(self):
+ """Remove and return an item from the queue without blocking.
+
+ Only get an item if one is immediately available. Otherwise
+ raise the Empty exception.
+ """
+ return self.get(False)
+
+ # Override these methods to implement other queue organizations
+ # (e.g. stack or priority queue).
+ # These will only be called with appropriate locks held
+
+ # Initialize the queue representation
+ def _init(self, maxsize):
+ self.queue = deque()
+
+ def _qsize(self, len=len):
+ return len(self.queue)
+
+ # Put a new item in the queue
+ def _put(self, item):
+ self.queue.append(item)
+
+ # Get an item from the queue
+ def _get(self):
+ return self.queue.popleft()
+
+
+class PriorityQueue(Queue):
+ '''Variant of Queue that retrieves open entries in priority order (lowest first).
+
+ Entries are typically tuples of the form: (priority number, data).
+ '''
+
+ def _init(self, maxsize):
+ self.queue = []
+
+ def _qsize(self, len=len):
+ return len(self.queue)
+
+ def _put(self, item, heappush=heapq.heappush):
+ heappush(self.queue, item)
+
+ def _get(self, heappop=heapq.heappop):
+ return heappop(self.queue)
+
+
+class LifoQueue(Queue):
+ '''Variant of Queue that retrieves most recently added entries first.'''
+
+ def _init(self, maxsize):
+ self.queue = []
+
+ def _qsize(self, len=len):
+ return len(self.queue)
+
+ def _put(self, item):
+ self.queue.append(item)
+
+ def _get(self):
+ return self.queue.pop()