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：