python下线程以及锁

1、python多线程

 #encoding=utf-8
 """
 python多线程，并非真正意义上的多线程
 全局锁：在指定时间里，有且只有一个线程在运行
  """
 import threading
 import time

 def test(p):
     time.sleep(0.1)
     print p

 # a = threading.Thread(target=test)
 # b = threading.Thread(target=test)
 # a.start()
 # b.start()
 #
 # a.join()
 # b.join()

 lst =[]
 for i in xrange(0, 15):
     th = threading.Thread(target=test, args=[i])
     lst.append(th)

 for i in lst:
     i.start()

 for i in lst:
     i.join()
 print "primary thread end!!!"

2、python下的锁

 #encoding=utf-8

 """
 1、python全局锁：GLT
   python多线程在任意时刻下只有一个线程在运行，它是线程安全的
 """

 import threading

 num = 0
 def t():
     global num
     num +=1
     print num

 for i in xrange(0, 10):
     d = threading.Thread(target=t)
     d.start()

 import time
 b_time = time.time()
 _a = threading.Thread(target=t)
 _b = threading.Thread(target=t)
 _a.start()
 _b.start()

 _a.join()
 _b.join()

 print time.time()-b_time

 """
 加锁：acquire()
 解锁：release()
 RLock()可重入锁
 """
 import threading
 mlock = threading.Lock()
 #mlock = threading.RLock()

 num_01 = 0
 def a():
     global num_01
     mlock.acquire()
     num_01 += 1
     mlock.release()
     print num_01

 for i in xrange(0, 10):
     d = threading.Thread(target=a)
     d.start()