锁

lock(1次放1个):

import threading
import time
v = []
lock = threading.Lock()
def func(arg):
    v.append(arg)
    time.sleep(0.01)
    m = v[-1]
    print(arg,m)
for i in range(10):
    t =threading.Thread(target=func,args=(i,))
    t.start()
结果:
01 9
 9
3 9
24 9
 9
7 5 9
6 99

8 9
9 9

线程不安全

import threading
import time
v = []
lock = threading.Lock()
def func(arg):
    lock.acquire()
    v.append(arg)
    time.sleep(0.01)
    m = v[-1]
    print(arg,m)
    lock.release()
for i in range(10):
    t =threading.Thread(target=func,args=(i,))
    t.start()

线程安全

　　lock只能加一把锁,加多把锁就会产生死锁.

Rlock(1次放1个):

import threading
import time
v = []
lock = threading.RLock()
def func(arg):
    lock.acquire()
    lock.acquire()
    v.append(arg)
    time.sleep(0.01)
    m = v[-1]
    print(arg,m)
    lock.release()
    lock.release()
for i in range(10):
    t =threading.Thread(target=func,args=(i,))
    t.start()
结果:
0 0
1 1
2 2
3 3
4 4
5 5
6 6
7 7
8 8
9 9

RLock

　　Rlock可以加多把锁.

BoundedSemaphore(1次放N个)信号量(N:指定数量个):

import time
import threading
lock = threading.BoundedSemaphore(3)
def func(arg):
    lock.acquire()
    print(arg)
    time.sleep(1)
    lock.release()
for i in range(20):
    t =threading.Thread(target=func,args=(i,))
    t.start()
结果:
0
1
2
3
5
4
6
7
8
9
1011

12
13
14
15
1716

18
19

View Code

Condition(1次放x个)(x:不固定数量个):

import time
import threading
lock = threading.Condition()
def func(arg):
    print('线程进来了')
    lock.acquire()
    lock.wait() # 加锁
    print(arg)
    time.sleep(1)
    lock.release()
for i in range(10):
    t =threading.Thread(target=func,args=(i,))
    t.start()
while True:
    inp = int(input('>>>'))
    lock.acquire()
    lock.notify(inp)
    lock.release()

方式一

import time
import threading
lock = threading.Condition()
def xxxx():
    print('来执行函数了')
    input(">>>")
    ct = threading.current_thread() # 获取当前线程
    ct.getName()
    return True

def func(arg):
    print('线程进来了')
    lock.wait_for(xxxx)
    print(arg)
    time.sleep(1)

for i in range(10):
    t =threading.Thread(target=func,args=(i,))
    t.start()

方式二

Event(1次放所有):

import time
import threading
lock = threading.Event()
def func(arg):
    print('线程来了')
    lock.wait() # 加锁：红灯
    print(arg)
for i in range(10):
    t =threading.Thread(target=func,args=(i,))
    t.start()
input(">>>>")
lock.set() # 绿灯
lock.clear() # 再次变红灯
for i in range(10):
    t =threading.Thread(target=func,args=(i,))
    t.start()
input(">>>>")
lock.set()

红绿灯