一，守护线程
守护线程和守护进程是一样的，都是随着主进程或者主线程的结束而结束
from threading import Threadimport timedef func(): print('22') time.sleep(1) print('22')t= Thread(target=func)t.setDaemon(True)t.start() C:\Users\hc\AppData\Local\Programs\Python\Python36\python3.exe C:/s9/day39/39.py22Process finished with exit code 0
当我们再起一个线程时：
from threading import Threadimport timedef func(): print('11') time.sleep(1) print('22')t= Thread(target=func)t.setDaemon(True)t.start()t1= Thread(target=func)t1.start() C:\Users\hc\AppData\Local\Programs\Python\Python36\python3.exe C:/s9/day39/39.py11112222Process finished with exit code 0
二，线程的锁
from threading import Threadfrom threading import Lockimport timedef func(): global n time.sleep(1) # l.acquire() n-=1 # l.release()n=10l=Lock()l1=[]for i in range(10): t=Thread(target=func) t.start() l1.append(t)[t.join() for t in l1]print(n)
C:\Users\hc\AppData\Local\Programs\Python\Python36\python3.exe C:/s9/day39/39.py0Process finished with exit code 0
有种特殊情况：
from threading import Threadfrom threading import Lockimport timedef func(): global n time.sleep(1) # l.acquire() tt=n #从进程中获取值 time.sleep(1) n=tt-1 #再返回进程 # l.release()n=10l=Lock()l1=[]for i in range(10): t=Thread(target=func) t.start() l1.append(t)[t.join() for t in l1]print(n)
C:\Users\hc\AppData\Local\Programs\Python\Python36\python3.exe C:/s9/day39/39.py9Process finished with exit code 0
这种情况还是要加锁的：
from threading import Threadfrom threading import Lockimport timedef func(): global n time.sleep(1) l.acquire() tt=n time.sleep(1) n=tt-1 l.release()n=10l=Lock()l1=[]for i in range(10): t=Thread(target=func) t.start() l1.append(t)[t.join() for t in l1]print(n)
GIL锁的不是数据，而是线程
三，死锁
from threading import RLockfrom threading import Threadfrom threading import Lockimport timea=Lock()b=Lock()def kill(name): a.acquire() print('%s拿到枪了'%name) b.acquire() print('%s拿到子弹了'%name) print('%s杀人了' % name) b.release() a.release()def kill1(name): b.acquire() print('%s拿到子弹了' % name) time.sleep(1) a.acquire() print('%s拿到枪了' % name) print('%s杀人了' % name) a.release() b.release()Thread(target=kill,args=('二狗',)).start()Thread(target=kill1,args=('大狗',)).start()Thread(target=kill,args=('三狗',)).start()Thread(target=kill1,args=('四狗',)).start() C:\Users\hc\AppData\Local\Programs\Python\Python36\python3.exe C:/s9/day39/39.py二狗拿到枪了二狗拿到子弹了二狗杀人了大狗拿到子弹了三狗拿到枪了
这就是死锁现象了，怎么解决这个问题呢？
from threading import RLockfrom threading import Threadfrom threading import Lockimport timeb=a=RLock()def kill(name): a.acquire() print('%s拿到枪了'%name) b.acquire() print('%s拿到子弹了'%name) print('%s杀人了' % name) b.release() a.release()def kill1(name): b.acquire() print('%s拿到子弹了' % name) time.sleep(1) a.acquire() print('%s拿到枪了' % name) print('%s杀人了' % name) a.release() b.release()Thread(target=kill,args=('二狗',)).start()Thread(target=kill1,args=('大狗',)).start()Thread(target=kill,args=('三狗',)).start()Thread(target=kill1,args=('四狗',)).start() C:\Users\hc\AppData\Local\Programs\Python\Python36\python3.exe C:/s9/day39/39.py二狗拿到枪了二狗拿到子弹了二狗杀人了大狗拿到子弹了大狗拿到枪了大狗杀人了三狗拿到枪了三狗拿到子弹了三狗杀人了四狗拿到子弹了四狗拿到枪了四狗杀人了Process finished with exit code 0
用RLock就可以解决这个问题了
lock是互斥锁
RLock是递归锁
四 信号量
from threading import Threadfrom threading import Semaphoreimport timeimport randomdef func(i,sem): sem.acquire() print('我是%s'%i) time.sleep(random.random()) print('我是%s'%i)sem=Semaphore(5)for i in range(10): Thread(target=func,args=(i,sem)).start() C:\Users\hc\AppData\Local\Programs\Python\Python36\python3.exe C:/s9/day39/39.py我是0我是1我是2我是3我是4我是3我是4我是1我是2我是0
信号量和线程池的区别，信号量是一次就显示这些线程，而线程池是每次就开这么多线程
五，事件
from threading import Eventfrom threading import Threadfrom threading import Semaphoreimport timeimport randomdef func(): count = 1 while not e.is_set(): # 当事件的flag为False时才执行循环内的语句 if count > 3: raise TimeoutError print('尝试连接第%s次' % count) count += 1 e.wait(0.5) # 一直阻塞变成了只阻塞0.5 print('连接成功') # 收到check_conn函数内的set指令，让flag变为True跳出while循环,执行本句代码def check_conn(): ''' 检测数据库服务器的连接是否正常 ''' time.sleep(random.randint(1, 2)) # 模拟连接检测的时间 e.set() # 告诉事件的标志数据库可以连接e = Event()check = Thread(target=check_conn)check.start()conn = Thread(target=func)conn.start() C:\Users\hc\AppData\Local\Programs\Python\Python36\python3.exe C:/s9/day39/39.py尝试连接第1次尝试连接第2次连接成功Process finished with exit code 0
六，，条件
import threadingdef func(i): t.acquire() t.wait() print('hello%s'%i) t.release()if __name__=='__main__': t=threading.Condition()#条件，锁加wait（）功能 for i in range(10): threading.Thread(target=func,args=(i,)).start() while 1: info=input('>>>') if info=='q': break t.acquire() if info=='all': t.notify_all() else: t.notify(int(info)) t.release() C:\Users\hc\AppData\Local\Programs\Python\Python36\python3.exe C:/s9/day39/39.py>>>2>>>hello0hello1
根据你设定的条件，设定每次执行多少线程
七，定时器
from threading import Timerdef func(): print('hello')Timer(4,func).start() C:\Users\hc\AppData\Local\Programs\Python\Python36\python3.exe C:/s9/day39/39.pyhelloProcess finished with exit code 0
八，队列
import queuet=queue.LifoQueue()t.put(1)t.put(2)t.put(3)print(t.get())C:\Users\hc\AppData\Local\Programs\Python\Python36\python3.exe C:/s9/day39/39.py3Process finished with exit code 0
后进先出
import queuet=queue.PriorityQueue()t.put((1,'q'))t.put((4,'e'))t.put((3,'g'))t.put((3,'o'))print(t.get())print(t.get())print(t.get())print(t.get())
C:\Users\hc\AppData\Local\Programs\Python\Python36\python3.exe C:/s9/day39/39.py(1, 'q')(3, 'g')(3, 'o')(4, 'e')Process finished with exit code 0
# 值越小越优先,值相同就asc码小的先出
九，concurrent
import timeimport randomfrom concurrent import futuresdef func(n): print(n) time.sleep(random.randint(1,3)) return n*'*'def fu(c): print(c.result())f=futures.ThreadPoolExecutor(3)#线程池f.submit(func,2)#submit=start
C:\Users\hc\AppData\Local\Programs\Python\Python36\python3.exe C:/s9/day39/39.py2Process finished with exit code 0
返回值：
import timeimport randomfrom concurrent import futuresdef func(n): print(n) time.sleep(random.randint(1,3)) return n*'*'def fu(c): print(c.result())f=futures.ThreadPoolExecutor(3)#线程池t=f.submit(func,2)#submit=startprint(t.result())#result打印返回值C:\Users\hc\AppData\Local\Programs\Python\Python36\python3.exe C:/s9/day39/39.py2**Process finished with exit code 0
import timeimport randomfrom concurrent import futuresdef func(n): print(n) time.sleep(random.randint(1,3)) return n*'*'def fu(c): print(c.result())f=futures.ThreadPoolExecutor(3)#线程池l=[]for i in range(10): t=f.submit(func,i)#submit=start l.append(t)f.shutdown()#相当于close()和join()集合体for i in l: print(i.result())C:\Users\hc\AppData\Local\Programs\Python\Python36\python3.exe C:/s9/day39/39.py0123456789*********************************************Process finished with exit code 0
回调：
import timeimport randomfrom concurrent import futuresdef func(n): # print(n) time.sleep(random.randint(1,3)) return n*'*'def fu(c): print(c.result())f=futures.ThreadPoolExecutor(3)#线程池l=[]for i in range(10):# t=f.submit(func,i)#submit=start# l.append(t)# f.shutdown()#相当于close()和join()集合体# for i in l:# print(i.result()) f.submit(func,i).add_done_callback(fu)#回调C:\Users\hc\AppData\Local\Programs\Python\Python36\python3.exe C:/s9/day39/39.py*********************************************Process finished with exit code 0
posted on 2018-02-07 22:27 阅读( ...) 评论( ...)