Introduction of practical Application of Lock in Python timer

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Practical application of Lock in Python timer

Lock/RLock and C#lock are similar. The difference is that Lock/RLock only needs to "lock" itself, while C#lock has to find another reference type object. Lock has a problem is that the same thread can not be "locked" multiple times, otherwise it will deadlock. RLock doesn't have this problem, it handles both "owning thread" and "recurrence level" states, and only increments counters for multiple lock requests from the same thread.

Each call to release() decrements the counter until 0 releases the lock, so remember that acquire() and release() appear in pairs. Just use RLock and forget Lock.

unlocked version:

def test(): for i in range(3): print currentThread().name, i sleep(1) for i in range(2): Thread(target = test).start()

Output:

$ ./ main.py Thread-1 0 Thread-2 0 Thread-1 1 Thread-2 1 Thread-1 2 Thread-2 2

Lock version:

lock = RLock() def test(): lock.acquire() try: for i in range(3): print currentThread().name, i sleep(1) finally: lock.release() for i in range(2): Thread(target = test).start()

Output:

$ ./ main.py Thread-1 0 Thread-1 1 Thread-1 2 Thread-2 0 Thread-2 1 Thread-2 2

RLock implements Context Management Protocol, which automatically calls acquire() and release() functions, so directly implement C#"lock(o) {... }"。

lock = RLock() def test(): with lock: for i in range(3): print currentThread().name, i sleep(1) for i in range(2): Thread(target = test).start() Thank you for reading, the above is the "practical application of Lock in Python timer" content, after the study of this article, I believe that we have a deeper understanding of the practical application of Lock in Python timer, the specific use of the situation also needs to be verified. Here is, Xiaobian will push more articles related to knowledge points for everyone, welcome to pay attention!