Python中有两种锁，一个锁是原始的锁（原语）， 不可重入，而另一种锁则是可重入的锁即递归锁。而是thread模块中，只提供了不可重入的锁，而在threading中则提供这两种锁。
可重入：当一个线程拥有一个锁的使用权后，再次获取锁的使用权时，不会阻塞，会立马得到使用权，则原始锁的话，则不行，会阻塞。
方法一：thead的不可重入锁
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import
thread
import
time
lock =
thread.allocate_lock()
def Count(id):
global
num;
while
True:
lock.acquire()
if
num <=
10:
print
"Thread id is : %s The num is %s\n"
% (id, str(num))
num =
num +
1
else:
break
lock.release()
else:
thread.exit_thread()
if __name__ ==
"__main__":
num =
1
thread.start_new_thread(Count, (‘A‘,))
thread.start_new_thread(Count, (‘B‘,))
time.sleep(5)
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方法二：theading的Lock(不可重入锁)
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import
threading
import
time
lock =
threading.Lock()
def Count(id):
global
num;
while
True:
lock.acquire()
if
num <=
10:
print
"Thread id is : %s The num is %s\n"
% (id, str(num))
num =
num +
1
else:
break
lock.release()
if __name__ ==
"__main__":
num =
1
t1 =
threading.Thread(target=Count, args=(‘A‘, ))
t2 =
threading.Thread(target=Count, args=(‘B‘, ))
t1.start()
t2.start()
time.sleep(5)
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方法三：threading的RLock(可重入)
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import
threading
import
time
lock =
threading.RLock()
def CountNum(id):
global
num
lock.acquire()
if
num <=
10:
print
"Thread id is : %s The num is %s\n"
% (id, str(num))
num =
num +
1
CountNum(id)
lock.release()
if __name__ ==
"__main__":
num =
1
t1 =
threading.Thread(target=CountNum, args=(‘A‘))
t1.start()
time.sleep(5)
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