Python--day41--递归锁Rlock

1,递归锁Rlock：递归锁是为了解决死锁问题，且递归锁的特点是在同一个线程中可以被acquire()多次

多个acquire()在递归锁中不会阻塞，而互斥锁Lock就会阻塞

代码示例：

 from threading import RLock

 rlock = RLock()
 #多个acquire()在递归锁中不会阻塞，而线程锁Lock就会阻塞
 rlock.acquire()
 rlock.acquire()
 rlock.acquire()
 rlock.acquire()
 print(123)

运行结果：

2，递归锁图示：（本质上为一串钥匙）

3，递归锁解决科学家吃面问题：

 import time
 from threading import RLock, Thread

 noodle_lock = fork_lock = RLock()       #一个钥匙串上的两把钥匙

 def eat1(name):
     noodle_lock.acquire()       #一把钥匙，说明一串钥匙都在我手上了
     print('%s拿到面了'%name)
     fork_lock.acquire()
     print('%s拿到叉子了'%name)
     print('%s吃面'%name)
     fork_lock.release()
     noodle_lock.release()

 def eat2(name):
     fork_lock.acquire()
     print('%s拿到叉子了' % name)
     time.sleep(1)
     noodle_lock.acquire()
     print('%s拿到面了'%name)
     print('%s吃面'%name)
     noodle_lock.release()
     fork_lock.release()

 Thread(target=eat1,args=('alex',)).start()
 Thread(target=eat2,args=('Egon',)).start()
 Thread(target=eat1,args=('bossjin',)).start()
 Thread(target=eat1,args=('nezha',)).start()

运行结果：