mutex
— 相互排斥支持
¶
Deprecated since version 2.6:
The
mutex
module has been removed in Python 3.
The
mutex
module defines a class that allows mutual-exclusion via acquiring and releasing locks. It does not require (or imply)
threading
or multi-tasking, though it could be useful for those purposes.
The
mutex
模块定义了下列类：
mutex.
mutex
¶
Create a new (unlocked) mutex.
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 zero 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 acquired.
mutex
objects have following methods:
mutex.
test
(
)
¶
Check whether the mutex is locked.
mutex.
testandset
(
)
¶
“Atomic” test-and-set, grab the lock if it is not set, and return
True
, otherwise, return
False
.
mutex.
lock
(
function
,
argument
)
¶
执行
function(argument)
, unless the mutex is locked. In the case it is locked, place the function and argument on the queue. See
unlock()
for explanation of when
function(argument)
is executed in that case.
mutex.
unlock
(
)
¶
Unlock the mutex if queue is empty, otherwise execute the first element in the queue.