Mercurial > cpython-lru_cache-weakref

annotate Lib/Queue.py @ 16413:8819867f14ef legacy-trunk

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Patch derived from Trent's 101162: a Python/C API testing framework. STILL NEEDS UNIX BUILD CHANGES.
author Tim Peters <tim.peters@gmail.com>
date Fri, 02 Feb 2001 05:57:15 +0000
parents b5345e99596b
children 79d533934ac1
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
11691
e34991022571 Mass patch by Ka-Ping Yee:
Guido van Rossum <guido@python.org>
parents: 11267
diff changeset
1 """A multi-producer, multi-consumer queue."""
995
f025eef93130 New module implementing a multi-everything queue.
Guido van Rossum <guido@python.org>
parents:
diff changeset
2
16070
b5345e99596b added __all__ lists to a number of Python modules
Skip Montanaro <skip@pobox.com>
parents: 15902
diff changeset
3 __all__ = ["Queue","Empty","Full"]
b5345e99596b added __all__ lists to a number of Python modules
Skip Montanaro <skip@pobox.com>
parents: 15902
diff changeset
4
15902
eef321b6e41c Variant of Skip's patch 103246 (Remove unneeded string exception compat from Queue).
Tim Peters <tim.peters@gmail.com>
parents: 13050
diff changeset
5 class Empty(Exception):
eef321b6e41c Variant of Skip's patch 103246 (Remove unneeded string exception compat from Queue).
Tim Peters <tim.peters@gmail.com>
parents: 13050
diff changeset
6 "Exception raised by Queue.get(block=0)/get_nowait()."
eef321b6e41c Variant of Skip's patch 103246 (Remove unneeded string exception compat from Queue).
Tim Peters <tim.peters@gmail.com>
parents: 13050
diff changeset
7 pass
eef321b6e41c Variant of Skip's patch 103246 (Remove unneeded string exception compat from Queue).
Tim Peters <tim.peters@gmail.com>
parents: 13050
diff changeset
8
eef321b6e41c Variant of Skip's patch 103246 (Remove unneeded string exception compat from Queue).
Tim Peters <tim.peters@gmail.com>
parents: 13050
diff changeset
9 class Full(Exception):
eef321b6e41c Variant of Skip's patch 103246 (Remove unneeded string exception compat from Queue).
Tim Peters <tim.peters@gmail.com>
parents: 13050
diff changeset
10 "Exception raised by Queue.put(block=0)/put_nowait()."
eef321b6e41c Variant of Skip's patch 103246 (Remove unneeded string exception compat from Queue).
Tim Peters <tim.peters@gmail.com>
parents: 13050
diff changeset
11 pass
995
f025eef93130 New module implementing a multi-everything queue.
Guido van Rossum <guido@python.org>
parents:
diff changeset
12
f025eef93130 New module implementing a multi-everything queue.
Guido van Rossum <guido@python.org>
parents:
diff changeset
13 class Queue:
11267
2b26e48a85a6 Make the maxsize constructor argument default to 0 (an unlimited queue size).
Guido van Rossum <guido@python.org>
parents: 10120
diff changeset
14 def __init__(self, maxsize=0):
7755
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
15 """Initialize a queue object with a given maximum size.
995
f025eef93130 New module implementing a multi-everything queue.
Guido van Rossum <guido@python.org>
parents:
diff changeset
16
7755
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
17 If maxsize is <= 0, the queue size is infinite.
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
18 """
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
19 import thread
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
20 self._init(maxsize)
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
21 self.mutex = thread.allocate_lock()
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
22 self.esema = thread.allocate_lock()
8197
3a55b4c5e3c7 Replace all calls to acquire_lock() and release_lock() with acquire()
Guido van Rossum <guido@python.org>
parents: 7926
diff changeset
23 self.esema.acquire()
7755
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
24 self.fsema = thread.allocate_lock()
995
f025eef93130 New module implementing a multi-everything queue.
Guido van Rossum <guido@python.org>
parents:
diff changeset
25
6612
4b2d8dc92db4 (Queue.Empty): When class based exceptions are in force, derive this
Barry Warsaw <barry@python.org>
parents: 1463
diff changeset
26 def qsize(self):
10120
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
27 """Return the approximate size of the queue (not reliable!)."""
8197
3a55b4c5e3c7 Replace all calls to acquire_lock() and release_lock() with acquire()
Guido van Rossum <guido@python.org>
parents: 7926
diff changeset
28 self.mutex.acquire()
7755
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
29 n = self._qsize()
8197
3a55b4c5e3c7 Replace all calls to acquire_lock() and release_lock() with acquire()
Guido van Rossum <guido@python.org>
parents: 7926
diff changeset
30 self.mutex.release()
7755
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
31 return n
995
f025eef93130 New module implementing a multi-everything queue.
Guido van Rossum <guido@python.org>
parents:
diff changeset
32
6612
4b2d8dc92db4 (Queue.Empty): When class based exceptions are in force, derive this
Barry Warsaw <barry@python.org>
parents: 1463
diff changeset
33 def empty(self):
10120
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
34 """Return 1 if the queue is empty, 0 otherwise (not reliable!)."""
8197
3a55b4c5e3c7 Replace all calls to acquire_lock() and release_lock() with acquire()
Guido van Rossum <guido@python.org>
parents: 7926
diff changeset
35 self.mutex.acquire()
7755
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
36 n = self._empty()
8197
3a55b4c5e3c7 Replace all calls to acquire_lock() and release_lock() with acquire()
Guido van Rossum <guido@python.org>
parents: 7926
diff changeset
37 self.mutex.release()
7755
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
38 return n
995
f025eef93130 New module implementing a multi-everything queue.
Guido van Rossum <guido@python.org>
parents:
diff changeset
39
6612
4b2d8dc92db4 (Queue.Empty): When class based exceptions are in force, derive this
Barry Warsaw <barry@python.org>
parents: 1463
diff changeset
40 def full(self):
10120
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
41 """Return 1 if the queue is full, 0 otherwise (not reliable!)."""
8197
3a55b4c5e3c7 Replace all calls to acquire_lock() and release_lock() with acquire()
Guido van Rossum <guido@python.org>
parents: 7926
diff changeset
42 self.mutex.acquire()
7755
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
43 n = self._full()
8197
3a55b4c5e3c7 Replace all calls to acquire_lock() and release_lock() with acquire()
Guido van Rossum <guido@python.org>
parents: 7926
diff changeset
44 self.mutex.release()
7755
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
45 return n
995
f025eef93130 New module implementing a multi-everything queue.
Guido van Rossum <guido@python.org>
parents:
diff changeset
46
10120
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
47 def put(self, item, block=1):
7926
e29d435ab142 Clarify that put *blocks* when the queue is full. Add some blank
Guido van Rossum <guido@python.org>
parents: 7755
diff changeset
48 """Put an item into the queue.
e29d435ab142 Clarify that put *blocks* when the queue is full. Add some blank
Guido van Rossum <guido@python.org>
parents: 7755
diff changeset
49
10120
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
50 If optional arg 'block' is 1 (the default), block if
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
51 necessary until a free slot is available. Otherwise (block
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
52 is 0), put an item on the queue if a free slot is immediately
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
53 available, else raise the Full exception.
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
54 """
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
55 if block:
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
56 self.fsema.acquire()
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
57 elif not self.fsema.acquire(0):
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
58 raise Full
8197
3a55b4c5e3c7 Replace all calls to acquire_lock() and release_lock() with acquire()
Guido van Rossum <guido@python.org>
parents: 7926
diff changeset
59 self.mutex.acquire()
7755
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
60 was_empty = self._empty()
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
61 self._put(item)
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
62 if was_empty:
8197
3a55b4c5e3c7 Replace all calls to acquire_lock() and release_lock() with acquire()
Guido van Rossum <guido@python.org>
parents: 7926
diff changeset
63 self.esema.release()
7755
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
64 if not self._full():
8197
3a55b4c5e3c7 Replace all calls to acquire_lock() and release_lock() with acquire()
Guido van Rossum <guido@python.org>
parents: 7926
diff changeset
65 self.fsema.release()
3a55b4c5e3c7 Replace all calls to acquire_lock() and release_lock() with acquire()
Guido van Rossum <guido@python.org>
parents: 7926
diff changeset
66 self.mutex.release()
995
f025eef93130 New module implementing a multi-everything queue.
Guido van Rossum <guido@python.org>
parents:
diff changeset
67
10120
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
68 def put_nowait(self, item):
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
69 """Put an item into the queue without blocking.
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
70
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
71 Only enqueue the item if a free slot is immediately available.
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
72 Otherwise raise the Full exception.
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
73 """
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
74 return self.put(item, 0)
7926
e29d435ab142 Clarify that put *blocks* when the queue is full. Add some blank
Guido van Rossum <guido@python.org>
parents: 7755
diff changeset
75
10120
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
76 def get(self, block=1):
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
77 """Remove and return an item from the queue.
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
78
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
79 If optional arg 'block' is 1 (the default), block if
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
80 necessary until an item is available. Otherwise (block is 0),
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
81 return an item if one is immediately available, else raise the
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
82 Empty exception.
7755
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
83 """
10120
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
84 if block:
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
85 self.esema.acquire()
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
86 elif not self.esema.acquire(0):
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
87 raise Empty
8197
3a55b4c5e3c7 Replace all calls to acquire_lock() and release_lock() with acquire()
Guido van Rossum <guido@python.org>
parents: 7926
diff changeset
88 self.mutex.acquire()
7755
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
89 was_full = self._full()
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
90 item = self._get()
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
91 if was_full:
8197
3a55b4c5e3c7 Replace all calls to acquire_lock() and release_lock() with acquire()
Guido van Rossum <guido@python.org>
parents: 7926
diff changeset
92 self.fsema.release()
7755
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
93 if not self._empty():
8197
3a55b4c5e3c7 Replace all calls to acquire_lock() and release_lock() with acquire()
Guido van Rossum <guido@python.org>
parents: 7926
diff changeset
94 self.esema.release()
3a55b4c5e3c7 Replace all calls to acquire_lock() and release_lock() with acquire()
Guido van Rossum <guido@python.org>
parents: 7926
diff changeset
95 self.mutex.release()
7755
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
96 return item
995
f025eef93130 New module implementing a multi-everything queue.
Guido van Rossum <guido@python.org>
parents:
diff changeset
97
6612
4b2d8dc92db4 (Queue.Empty): When class based exceptions are in force, derive this
Barry Warsaw <barry@python.org>
parents: 1463
diff changeset
98 def get_nowait(self):
10120
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
99 """Remove and return an item from the queue without blocking.
7926
e29d435ab142 Clarify that put *blocks* when the queue is full. Add some blank
Guido van Rossum <guido@python.org>
parents: 7755
diff changeset
100
10120
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
101 Only get an item if one is immediately available. Otherwise
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
102 raise the Empty exception.
7755
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
103 """
10120
5b15642e7bdf Tim Peters:
Guido van Rossum <guido@python.org>
parents: 8197
diff changeset
104 return self.get(0)
6612
4b2d8dc92db4 (Queue.Empty): When class based exceptions are in force, derive this
Barry Warsaw <barry@python.org>
parents: 1463
diff changeset
105
4b2d8dc92db4 (Queue.Empty): When class based exceptions are in force, derive this
Barry Warsaw <barry@python.org>
parents: 1463
diff changeset
106 # Override these methods to implement other queue organizations
4b2d8dc92db4 (Queue.Empty): When class based exceptions are in force, derive this
Barry Warsaw <barry@python.org>
parents: 1463
diff changeset
107 # (e.g. stack or priority queue).
4b2d8dc92db4 (Queue.Empty): When class based exceptions are in force, derive this
Barry Warsaw <barry@python.org>
parents: 1463
diff changeset
108 # These will only be called with appropriate locks held
995
f025eef93130 New module implementing a multi-everything queue.
Guido van Rossum <guido@python.org>
parents:
diff changeset
109
6612
4b2d8dc92db4 (Queue.Empty): When class based exceptions are in force, derive this
Barry Warsaw <barry@python.org>
parents: 1463
diff changeset
110 # Initialize the queue representation
4b2d8dc92db4 (Queue.Empty): When class based exceptions are in force, derive this
Barry Warsaw <barry@python.org>
parents: 1463
diff changeset
111 def _init(self, maxsize):
7755
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
112 self.maxsize = maxsize
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
113 self.queue = []
995
f025eef93130 New module implementing a multi-everything queue.
Guido van Rossum <guido@python.org>
parents:
diff changeset
114
6612
4b2d8dc92db4 (Queue.Empty): When class based exceptions are in force, derive this
Barry Warsaw <barry@python.org>
parents: 1463
diff changeset
115 def _qsize(self):
7755
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
116 return len(self.queue)
995
f025eef93130 New module implementing a multi-everything queue.
Guido van Rossum <guido@python.org>
parents:
diff changeset
117
13050
a195962e389c typos fixed by Rob Hooft
Jeremy Hylton <jeremy@alum.mit.edu>
parents: 11691
diff changeset
118 # Check whether the queue is empty
6612
4b2d8dc92db4 (Queue.Empty): When class based exceptions are in force, derive this
Barry Warsaw <barry@python.org>
parents: 1463
diff changeset
119 def _empty(self):
7755
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
120 return not self.queue
995
f025eef93130 New module implementing a multi-everything queue.
Guido van Rossum <guido@python.org>
parents:
diff changeset
121
6612
4b2d8dc92db4 (Queue.Empty): When class based exceptions are in force, derive this
Barry Warsaw <barry@python.org>
parents: 1463
diff changeset
122 # Check whether the queue is full
4b2d8dc92db4 (Queue.Empty): When class based exceptions are in force, derive this
Barry Warsaw <barry@python.org>
parents: 1463
diff changeset
123 def _full(self):
7755
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
124 return self.maxsize > 0 and len(self.queue) == self.maxsize
995
f025eef93130 New module implementing a multi-everything queue.
Guido van Rossum <guido@python.org>
parents:
diff changeset
125
6612
4b2d8dc92db4 (Queue.Empty): When class based exceptions are in force, derive this
Barry Warsaw <barry@python.org>
parents: 1463
diff changeset
126 # Put a new item in the queue
4b2d8dc92db4 (Queue.Empty): When class based exceptions are in force, derive this
Barry Warsaw <barry@python.org>
parents: 1463
diff changeset
127 def _put(self, item):
7755
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
128 self.queue.append(item)
995
f025eef93130 New module implementing a multi-everything queue.
Guido van Rossum <guido@python.org>
parents:
diff changeset
129
6612
4b2d8dc92db4 (Queue.Empty): When class based exceptions are in force, derive this
Barry Warsaw <barry@python.org>
parents: 1463
diff changeset
130 # Get an item from the queue
4b2d8dc92db4 (Queue.Empty): When class based exceptions are in force, derive this
Barry Warsaw <barry@python.org>
parents: 1463
diff changeset
131 def _get(self):
7755
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
132 item = self.queue[0]
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
133 del self.queue[0]
fb4b4d069cc7 Mass check-in after untabifying all files that need it.
Guido van Rossum <guido@python.org>
parents: 6612
diff changeset
134 return item