summaryrefslogtreecommitdiff
path: root/lib/python2.7/mutex.py
diff options
context:
space:
mode:
Diffstat (limited to 'lib/python2.7/mutex.py')
-rw-r--r--lib/python2.7/mutex.py55
1 files changed, 0 insertions, 55 deletions
diff --git a/lib/python2.7/mutex.py b/lib/python2.7/mutex.py
deleted file mode 100644
index f8acba4..0000000
--- a/lib/python2.7/mutex.py
+++ /dev/null
@@ -1,55 +0,0 @@
-"""Mutual exclusion -- for use with module sched
-
-A mutex has two pieces of state -- a 'locked' bit and a queue.
-When the mutex is not locked, the queue is empty.
-Otherwise, the queue contains 0 or more (function, argument) pairs
-representing functions (or methods) waiting to acquire the lock.
-When the mutex is unlocked while the queue is not empty,
-the first queue entry is removed and its function(argument) pair called,
-implying it now has the lock.
-
-Of course, no multi-threading is implied -- hence the funny interface
-for lock, where a function is called once the lock is aquired.
-"""
-from warnings import warnpy3k
-warnpy3k("the mutex module has been removed in Python 3.0", stacklevel=2)
-del warnpy3k
-
-from collections import deque
-
-class mutex:
- def __init__(self):
- """Create a new mutex -- initially unlocked."""
- self.locked = False
- self.queue = deque()
-
- def test(self):
- """Test the locked bit of the mutex."""
- return self.locked
-
- def testandset(self):
- """Atomic test-and-set -- grab the lock if it is not set,
- return True if it succeeded."""
- if not self.locked:
- self.locked = True
- return True
- else:
- return False
-
- def lock(self, function, argument):
- """Lock a mutex, call the function with supplied argument
- when it is acquired. If the mutex is already locked, place
- function and argument in the queue."""
- if self.testandset():
- function(argument)
- else:
- self.queue.append((function, argument))
-
- def unlock(self):
- """Unlock a mutex. If the queue is not empty, call the next
- function with its argument."""
- if self.queue:
- function, argument = self.queue.popleft()
- function(argument)
- else:
- self.locked = False