python note 32 鎖

一、lock鎖

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()

二、rlock鎖

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()

三、semaphore鎖

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()

四、condition鎖

import time
import threading

lock = threading.Condition()

# ############## 方式一 ##############

def func(arg):
    print('線程進來了')
    lock.acquire()
    lock.wait() # 加鎖

    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()


# ############## 方式二 ##############
"""
def xxxx():
    print('來執行函數了')
    input(">>>")
    # ct = threading.current_thread() # 獲取當前線程
    # ct.getName()
    return True

def func(arg):
    print('線程進來了')
    lock.wait_for(xxxx)
    print(arg)
    time.sleep(1)

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

"""

五、event鎖

import time
import threading

lock = threading.Event()

def func(arg):
    print('線程來了')
    lock.wait() # 加鎖：紅燈
    print(arg)

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

input(">>>>")
lock.set() # 綠燈

lock.clear() # 再次變紅燈

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

input(">>>>")
lock.set()

 六、threadinglocal

import time
import threading

v = threading.local()

def func(arg):
    # 內部會爲當前線程建立一個空間用於存儲：phone=本身的值
    v.phone = arg
    time.sleep(2)
    print(v.phone,arg) # 去當前線程本身空間取值

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

七、線程池

from concurrent.futures import ThreadPoolExecutor
import time

def task(a1,a2):
    time.sleep(2)
    print(a1,a2)

# 建立了一個線程池（最多5個線程）
pool = ThreadPoolExecutor(5)

for i in range(40):
    # 去線程池中申請一個線程，讓線程執行task函數。
    pool.submit(task,i,8)

八、生產者消費者模型

import time
import queue
import threading
q = queue.Queue() # 線程安全

def producer(id):
    """
    生產者
    :return:
    """
    while True:
        time.sleep(2)
        q.put('包子')
        print('廚師%s 生產了一個包子' %id )

for i in range(1,4):
    t = threading.Thread(target=producer,args=(i,))
    t.start()


def consumer(id):
    """
    消費者
    :return:
    """
    while True:
        time.sleep(1)
        v1 = q.get()
        print('顧客 %s 吃了一個包子' % id)

for i in range(1,3):
    t = threading.Thread(target=consumer,args=(i,))
    t.start()

 九、獲取當前線程

threading.current_process()