Python 35 线程（2）线程特性、守护线程、线程互斥锁

一：线程特性介绍

from threading import Thread
import time

n=100
def task():
    global n
    n=0

if __name__ == '__main__':
    t=Thread(target=task)
    t.start()
    t.join()
    print('主',n)


from threading import Thread
import time,os

def task():
    print('%s is running' %os.getpid())

if __name__ == '__main__':
    t=Thread(target=task)
    t.start()
    print('主',os.getpid())

from threading import Thread,active_count,current_thread
import time,os

def task():
    print('%s is running' %current_thread().name)
    time.sleep(2)

if __name__ == '__main__':
    t=Thread(target=task,)
    t.start()
    # t.join()
    # print('主',active_count())
    print('主',current_thread().name)

二：守护线程

from threading import Thread
import time

def task(name):
    print('%s is running' %name)
    time.sleep(2)
    print('%s is done' %name)

if __name__ == '__main__':
    t=Thread(target=task,args=('线程1',))
    t.daemon=True
    t.start()
    print('主')

from threading import Thread
from multiprocessing import Process
import time
def foo():
    print(123)
    time.sleep(1)
    print("end123")

def bar():
    print(456)
    time.sleep(3)
    print("end456")

if __name__ == '__main__':
    t1=Thread(target=foo)
    t2=Thread(target=bar)

    # t1=Process(target=foo)
    # t2=Process(target=bar)
    t1.daemon=True
    t1.start()
    t2.start()
    print("main-------")

三：线程互斥锁

from threading import Thread,Lock
import time

mutex=Lock()
n=100
def task():
    global n
    mutex.acquire()
    temp=n
    time.sleep(0.1)
    n=temp-1
    mutex.release()

if __name__ == '__main__':
    t_l=[]
    for i in range(100):
        t=Thread(target=task)
        t_l.append(t)
        t.start()

    for t in t_l:
        t.join()
    print(n)