diff options
Diffstat (limited to 'Lib/Queue.py')
| -rw-r--r-- | Lib/Queue.py | 170 |
1 files changed, 85 insertions, 85 deletions
diff --git a/Lib/Queue.py b/Lib/Queue.py index 1cec4e3..6710153 100644 --- a/Lib/Queue.py +++ b/Lib/Queue.py @@ -4,102 +4,102 @@ # exceptions, but also when -X option is used. try: class Empty(Exception): - pass + pass except TypeError: # string based exceptions - Empty = 'Queue.Empty' # Exception raised by get_nowait() + Empty = 'Queue.Empty' # Exception raised by get_nowait() class Queue: def __init__(self, maxsize): - """Initialize a queue object with a given maximum size. + """Initialize a queue object with a given maximum size. - If maxsize is <= 0, the queue size is infinite. - """ - import thread - self._init(maxsize) - self.mutex = thread.allocate_lock() - self.esema = thread.allocate_lock() - self.esema.acquire_lock() - self.fsema = thread.allocate_lock() + If maxsize is <= 0, the queue size is infinite. + """ + import thread + self._init(maxsize) + self.mutex = thread.allocate_lock() + self.esema = thread.allocate_lock() + self.esema.acquire_lock() + self.fsema = thread.allocate_lock() def qsize(self): - """Returns the approximate size of the queue (not reliable!).""" - self.mutex.acquire_lock() - n = self._qsize() - self.mutex.release_lock() - return n + """Returns the approximate size of the queue (not reliable!).""" + self.mutex.acquire_lock() + n = self._qsize() + self.mutex.release_lock() + return n def empty(self): - """Returns 1 if the queue is empty, 0 otherwise (not reliable!).""" - self.mutex.acquire_lock() - n = self._empty() - self.mutex.release_lock() - return n + """Returns 1 if the queue is empty, 0 otherwise (not reliable!).""" + self.mutex.acquire_lock() + n = self._empty() + self.mutex.release_lock() + return n def full(self): - """Returns 1 if the queue is full, 0 otherwise (not reliable!).""" - self.mutex.acquire_lock() - n = self._full() - self.mutex.release_lock() - return n + """Returns 1 if the queue is full, 0 otherwise (not reliable!).""" + self.mutex.acquire_lock() + n = self._full() + self.mutex.release_lock() + return n def put(self, item): - """Put an item into the queue.""" - self.fsema.acquire_lock() - self.mutex.acquire_lock() - was_empty = self._empty() - self._put(item) - if was_empty: - self.esema.release_lock() - if not self._full(): - self.fsema.release_lock() - self.mutex.release_lock() + """Put an item into the queue.""" + self.fsema.acquire_lock() + self.mutex.acquire_lock() + was_empty = self._empty() + self._put(item) + if was_empty: + self.esema.release_lock() + if not self._full(): + self.fsema.release_lock() + self.mutex.release_lock() def get(self): - """Gets and returns an item from the queue. - This method blocks if necessary until an item is available. - """ - self.esema.acquire_lock() - self.mutex.acquire_lock() - was_full = self._full() - item = self._get() - if was_full: - self.fsema.release_lock() - if not self._empty(): - self.esema.release_lock() - self.mutex.release_lock() - return item + """Gets and returns an item from the queue. + This method blocks if necessary until an item is available. + """ + self.esema.acquire_lock() + self.mutex.acquire_lock() + was_full = self._full() + item = self._get() + if was_full: + self.fsema.release_lock() + if not self._empty(): + self.esema.release_lock() + self.mutex.release_lock() + return item # Get an item from the queue if one is immediately available, # raise Empty if the queue is empty or temporarily unavailable def get_nowait(self): - """Gets and returns an item from the queue. - Only gets an item if one is immediately available, Otherwise - this raises the Empty exception if the queue is empty or - temporarily unavailable. - """ - locked = self.esema.acquire_lock(0) - self.mutex.acquire_lock() - if self._empty(): - # The queue is empty -- we can't have esema - self.mutex.release_lock() - raise Empty - if not locked: - locked = self.esema.acquire_lock(0) - if not locked: - # Somebody else has esema - # but we have mutex -- - # go out of their way - self.mutex.release_lock() - raise Empty - was_full = self._full() - item = self._get() - if was_full: - self.fsema.release_lock() - if not self._empty(): - self.esema.release_lock() - self.mutex.release_lock() - return item + """Gets and returns an item from the queue. + Only gets an item if one is immediately available, Otherwise + this raises the Empty exception if the queue is empty or + temporarily unavailable. + """ + locked = self.esema.acquire_lock(0) + self.mutex.acquire_lock() + if self._empty(): + # The queue is empty -- we can't have esema + self.mutex.release_lock() + raise Empty + if not locked: + locked = self.esema.acquire_lock(0) + if not locked: + # Somebody else has esema + # but we have mutex -- + # go out of their way + self.mutex.release_lock() + raise Empty + was_full = self._full() + item = self._get() + if was_full: + self.fsema.release_lock() + if not self._empty(): + self.esema.release_lock() + self.mutex.release_lock() + return item # XXX Need to define put_nowait() as well. @@ -110,26 +110,26 @@ class Queue: # Initialize the queue representation def _init(self, maxsize): - self.maxsize = maxsize - self.queue = [] + self.maxsize = maxsize + self.queue = [] def _qsize(self): - return len(self.queue) + return len(self.queue) # Check wheter the queue is empty def _empty(self): - return not self.queue + return not self.queue # Check whether the queue is full def _full(self): - return self.maxsize > 0 and len(self.queue) == self.maxsize + return self.maxsize > 0 and len(self.queue) == self.maxsize # Put a new item in the queue def _put(self, item): - self.queue.append(item) + self.queue.append(item) # Get an item from the queue def _get(self): - item = self.queue[0] - del self.queue[0] - return item + item = self.queue[0] + del self.queue[0] + return item |