Mutes鎖_遞迴鎖_訊號量semaphore
阿新 • • 發佈：2019-01-04
#!-*-coding:utf-8-*-
#加使用者態的鎖，與全域性直譯器鎖不一樣(GIL)
import threading, time
def run(n):
lock.acquire() #獲取使用者態鎖 也叫互斥鎖Mutex
global num #操作
#time.sleep(0.1) #加了sleep之後程式變序列的了 一般不要加
num +=1
lock.release() #釋放使用者態鎖
lock=threading.Lock()
num=0
t_objs = []
for i in range(1000):
t = threading.Thread(target=run, args=("t %s" % i,))
t.start()
t_objs.append(t) # 把每個執行緒例項都加進來 不阻塞後面執行緒的啟動
for t in t_objs: #取列表裡的每個執行緒
t.join() #等待並行的每個執行緒全都執行完畢 在往下走
print("----all threads has finished...",threading.current_thread(),threading.active_count())
print("num",num)
import threading, time
def run1():
print("grab the first part data")
lock.acquire()
global num
num +=
lock.release()
return num
def run2():
print("grab the second part data")
lock.acquire()
global num2
num2 += 1
lock.release()
return num2
def run3():
lock.acquire()
res = run1()
print('--------between run1 and run2-----')
res2 = run2()
lock.release()
print(res, res2)
num, num2 = 0, 0
lock = threading.RLock() #遞迴鎖
for i in range(1):
t = threading.Thread(target=run3)
t.start()
while threading.active_count() != 1:
print(threading.active_count())
else:
print('----all threads done---')
print(num, num2)
import threading,time
def run(n):
semaphore.acquire() #訊號量 相當於若干把鎖 同時開啟5個執行緒
time.sleep(1)
print("run the thread:%s\n"%n)
semaphore.release() #同時釋放5把鎖
if __name__=="__main__":
semaphore=threading.BoundedSemaphore(5) #最多允許5個執行緒同時執行 相當於有5把鎖
for i in range(20):
t=threading.Thread(target=run,args=(i,))
t.start()
while threading.active_count() !=1:
pass
else:
print("---all threads done----")