threading python2 和python3
from __future__ import division
from __future__ import print_function
import threading
balance = 0
def change_it(n):
global balance
balance +=n
balance -=n
def run_thread(n):
for i in range(10000):
change_it(n)
def create_thread():
for i in range(30):
t1 = threading.Thread(target=run_thread,args=(1,))
t2 = threading.Thread(target=run_thread,args=(-1,))
t1.start()
t2.start()
t1.join()
t2.join()
print(balance)
def _test_thread():
create_thread()
def test():
_test_thread()
test()
输出
Linux-4.15.0-36-generic-x86_64-with-Ubuntu-16.04-xenial
#39~16.04.1-Ubuntu SMP Tue Sep 25 08:59:23 UTC 2018
('64bit', 'ELF')
Python:2.7.12 (default, Dec 4 2017, 14:50:18)
[GCC 5.4.0 20160609]
6
6
-1
0
-28
-41
-40
-49
-56
-54
-60
-63
-68
-73
-69
-78
-53
-60
-53
-58
-48
-71
-82
-83
-130
-129
-111
-100
-84
-173
Linux-4.15.0-36-generic-x86_64-with-Ubuntu-16.04-xenial
#39~16.04.1-Ubuntu SMP Tue Sep 25 08:59:23 UTC 2018
('64bit', 'ELF')
Python:3.5.2 (default, Nov 23 2017, 16:37:01)
[GCC 5.4.0 20160609]
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
加锁后
from __future__ import division
from __future__ import print_function
import threading
balance = 0
lock = threading.Lock()
def change_it(n):
global balance
balance +=n
balance -=n
def run_thread(n):
for i in range(10000):
lock.acquire()
try:
change_it(n)
finally:
lock.release()
def create_thread():
for i in range(30):
t1 = threading.Thread(target=run_thread,args=(1,))
t2 = threading.Thread(target=run_thread,args=(-1,))
t1.start()
t2.start()
t1.join()
t2.join()
print(balance)
def _test_thread():
create_thread()
def test():
_test_thread()
test()
输出
Linux-4.15.0-36-generic-x86_64-with-Ubuntu-16.04-xenial
#39~16.04.1-Ubuntu SMP Tue Sep 25 08:59:23 UTC 2018
('64bit', 'ELF')
Python:2.7.12 (default, Dec 4 2017, 14:50:18)
[GCC 5.4.0 20160609]
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Linux-4.15.0-36-generic-x86_64-with-Ubuntu-16.04-xenial
#39~16.04.1-Ubuntu SMP Tue Sep 25 08:59:23 UTC 2018
('64bit', 'ELF')
Python:3.5.2 (default, Nov 23 2017, 16:37:01)
[GCC 5.4.0 20160609]
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
