python 多进程之间共享变量
多线程 进程间共享变量等
1、进程间共享变量 self.val=Value('i',init_value)
#进程间共享变量及列表类型
class Counter(object):
def __init__(self, ini=0):
self.val = Value('i', ini)
self.lock = Lock()
def increment(self):
with self.lock:
self.val.value=self.val.value+1
print('共享变量val自增1次：', self.value())
def value(self):
with self.lock: #这个with self.lock: 注释掉之后结果是一样的
return self.val.value
def func(counter_1):
for i in range(5):
time.sleep(0.01)
counter_1.increment()
if __name__ == '__main__':
counter = Counter(0)
ps = [Process(target=func,args=(counter,)) for i in range(5)]
for i in ps:
i.start()
for i in ps:
i.join()
print('counter.value():',counter.value())
2、通过 Value、Array实现进程间变量共享
from multiprocessing import Array,Value
#进程间共享变量及列表类型
def f(n,a):
n.value+=100
for i in range(len(a)):
a[i]*=-1
if __name__=='__main__':
num=Value('i',0) #理解成是一个共享对象
print('type(num):',type(num))
arr=Array('i',range(10)) #理解成是一个共享对象
print('type(arr):', type(arr))
p=Process(target=f,args=(num,arr))
p.start()
p.join()
print('num:',num.value)
print('arr:',list(arr))
print('主程序执行完成！！')
3、进程间共享字符串from ctypes import c_char_p s=Value(c_char_p,'hello')
from multiprocessing import Process,Manager,Value
from ctypes import c_char_p
def greet(sharestr):
sharestr.value+=',world'
if __name__=='__main__':
manager=Manager()
print(type(manager))
sharestr=manager.Value(c_char_p,'hello')
p=Process(target=greet,args=(sharestr,))
p.start()
p.join()
print(sharestr.value)
print(type(sharestr))
4、进程间共享列表、字典 manager=Manager（） manager.dict() manager.list(range(10))
def func(shared,sharel):
shared[1]='1'
shared['2']='2'
shared[0.25]=None
sharel.reverse()
if __name__=='__main__':
manager=Manager()
shared=manager.dict()
sharel=manager.list(range(10))
p=Process(target=func,args=(shared,sharel))
p.start()
p.join()
print(shared)
print(sharel)
5、进程间共享实例对象 BaseManager()
import time,os
import random
from multiprocessing import Pool,Value,Lock
from multiprocessing.managers import BaseManager
class MyManager(BaseManager):
pass
def Manager():
m=MyManager()
m.start()
return m
class Counter():
def __init__(self,ini=0):
self.val=Value('i',ini)
self.lock=Lock()
def increment(self):
with self.lock:
self.val.value=self.val.value+1
def value11(self):
with self.lock:
return self.val.value
MyManager.register('Counter',Counter)
def long_time_task(name,counter):
time.sleep(0.2)
print(' run task %s(%s)\n'%(name,os.getpid()))
start=time.time()
for i in range(10):
time.sleep(0.2)
counter.increment()
end=time.time()
print('task %s runs %s seconds.'%(name,(end-start)))
if __name__=='__main__':
manager=Manager()
counter=manager.Counter(0)
print('Parent process %s.'%os.getpid())
#p=Pool()
ps=[]
for i in range(5):
ps.append(Process(target=long_time_task,args=(str(i),counter)))
#p.apply_async(long_time_task,args=(str(i),counter))
#p.apply_async(target=long_time_task,args=(str(i),counter))
print('等待所有进程完成：')
#p.close()
for i in ps:
i.start()
for i in ps:
i.join()
#p.join()
print('全部完成')
print('counter.value11():',counter.value11())
方法二：
import time,os
import random
import multiprocessing as multip
from multiprocessing import Pool,Value,Lock,Process
from multiprocessing.managers import BaseManager
class MyManager(BaseManager):
pass
def Manager():
m=MyManager()
m.start()
return m
class Counter():
def __init__(self,ini=0):
self.val=Value('i',ini)
self.lock=Lock()
def increment(self):
with self.lock:
self.val.value=self.val.value+1
def value11(self):
with self.lock:
return self.val.value
MyManager.register('Counter',Counter)
def long_time_task(name,counter):
time.sleep(0.2)
print(' run task %s(%s)\n'%(name,os.getpid()))
start=time.time()
for i in range(10):
time.sleep(0.2)
counter.increment()
end=time.time()
print('task %s runs %s seconds.'%(name,(end-start)))
if __name__=='__main__':
#MyManager.register('Counter', Counter)
manager=Manager()
counter=manager.Counter(0)
print('Parent process %s.'%os.getpid())
p=Pool()
for i in range(5):
p.apply_async(long_time_task,args=(str(i),counter))
#p.apply_async(long_time_task,args=(str(i),counter))
#p.apply_async(target=long_time_task,args=(str(i),counter))
print('等待所有进程完成：')
p.close()
p.join()
print('全部完成')
print('counter.value11():',counter.value11())
方法三：
import multiprocessing as mp,time,random
from multiprocessing import *
from multiprocessing.managers import BaseManager
class Counter():
def __init__(self,a):
self.val=Value('i',a)
self.lock=Lock()
def increment(self):
with self.lock:
self.val.value+=1
#print('self.val的值为：%s'%self.val.value)
def get_value(self):
with self.lock:
return self.val.value
class MyManager(BaseManager):
pass
MyManager.register('Counter_copy',Counter)
def func(counter,a):
time.sleep(0.1)
for i in range(10):
counter.increment()
print('%s次的值为：%s'%(a,counter.get_value()))
if __name__=='__main__':
m=MyManager()
m.start()
counter=m.Counter_copy(0)
pool=Pool(2)
for i in range(5):
pool.apply_async(func,args=(counter,str(i)))
pool.close()
pool.join()
print('主程序执行完成！！')