python下线程以及锁

#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!!!"

#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()