1. 进程
- 进程间数据不共享
data_list = []
def task(arg):
data_list.append(arg)
print(data_list)
def run():
for i in range(10):
p = multiprocessing.Process(target=task,args=(i,))
# p = threading.Thread(target=task,args=(i,))
p.start()
if __name__ == '__main__':
run()
- 常用功能:
- join
- deamon
- name
- multiprocessing.current_process()
- multiprocessing.current_process().ident/pid
- 类继承方式创建进程
class MyProcess(multiprocessing.Process):
def run(self):
print('当前进程',multiprocessing.current_process())
def run():
p1 = MyProcess()
p1.start()
p2 = MyProcess()
p2.start()
if __name__ == '__main__':
run()
2. 进程间数据共享
Queue:
linux:
q = multiprocessing.Queue()
def task(arg,q):
q.put(arg)
def run():
for i in range(10):
p = multiprocessing.Process(target=task, args=(i, q,))
p.start()
while True:
v = q.get()
print(v)
run()
windows:
def task(arg,q):
q.put(arg)
if __name__ == '__main__':
q = multiprocessing.Queue()
for i in range(10):
p = multiprocessing.Process(target=task,args=(i,q,))
p.start()
while True:
v = q.get()
print(v)
Manager:（*）
Linux:
m = multiprocessing.Manager()
dic = m.dict()
def task(arg):
dic[arg] = 100
def run():
for i in range(10):
p = multiprocessing.Process(target=task, args=(i,))
p.start()
input('>>>')
print(dic.values())
if __name__ == '__main__':
run()
windows:
def task(arg,dic):
time.sleep(2)
dic[arg] = 100
if __name__ == '__main__':
m = multiprocessing.Manager()
dic = m.dict()
process_list = []
for i in range(10):
p = multiprocessing.Process(target=task, args=(i,dic,))
p.start()
process_list.append(p)
while True:
count = 0
for p in process_list:
if not p.is_alive():
count += 1
if count == len(process_list):
break
print(dic)
3. 进程锁
import time
import threading
import multiprocessing
lock = multiprocessing.RLock()
def task(arg):
print('鬼子来了')
lock.acquire()
time.sleep(2)
print(arg)
lock.release()
if __name__ == '__main__':
p1 = multiprocessing.Process(target=task,args=(1,))
p1.start()
p2 = multiprocessing.Process(target=task, args=(2,))
p2.start()
为什么要加锁？
4. 进程池
import time
from concurrent.futures import ThreadPoolExecutor,ProcessPoolExecutor
def task(arg):
time.sleep(2)
print(arg)
if __name__ == '__main__':
pool = ProcessPoolExecutor(5)
for i in range(10):
pool.submit(task,i)
