Python多程序操作初探

unix/linux作業系統提供了乙個fork()系統呼叫,python的os模組封裝了常見的系統呼叫，其中就包括fork，可以在python程式中輕鬆建立子程序：

import os

print('process (%s) start...' % os.getpid())
# only works on unix/linux/mac:
pid = os.fork()
if pid == 0:
print('i am child process (%s) and my parent is %s.' % (os.getpid(), os.getppid()))
else:
print('i (%s) just created a child process (%s).' % (os.getpid(), pid))

process (37) start...

i (37) just created a child process (38).
process (37) start...
i am child process (38) and my parent is 37.

multiprocessing模組提供了乙個process類來代表乙個程序物件

from multiprocessing import process

import os
# 子程序要執行的**
def run_proc(name):
print('run child process %s (%s)...' % (name, os.getpid()))
if __name__=='__main__':
print('parent process %s.' % os.getpid())
p = process(target=run_proc, args=('test',))
print('child process will start.')
p.start()
p.join()
print('child process end.')

d:\develop\python3.6\python.exe d:/develop/pythondemo/123/demo.py

parent process 13264.
child process will start.
run child process test (10648)...
child process end.

join()方法可以等待子程序結束後再繼續往下執行，通常用於程序間的同步。

from multiprocessing import pool

import os, time, random
def long_time_task(name):
print('run task %s (%s)...' % (name, os.getpid()))
start = time.time()
time.sleep(random.random() * 3)
end = time.time()
print('task %s runs %0.2f seconds.' % (name, (end - start)))
if __name__=='__main__':
print('parent process %s.' % os.getpid())
p = pool(4)
for i in range(5):
print('waiting for all subprocesses done...')
p.close()
p.join()
print('all subprocesses done.')

d:\develop\python3.6\python.exe d:/develop/pythondemo/123/demo.py

parent process 11476.
waiting for all subprocesses done...
run task 0 (11512)...
run task 1 (12492)...
run task 2 (8628)...
run task 3 (4300)...
task 2 runs 0.22 seconds.
run task 4 (8628)...
task 0 runs 0.66 seconds.
task 4 runs 1.03 seconds.
task 3 runs 1.76 seconds.
task 1 runs 2.89 seconds.
all subprocesses done.

初探PHP多程序

我們都知道php是單程序執行的，php處理多併發主要是依賴伺服器或php fpm的多程序及它們程序的復用，但php實現多程序也意義重大，尤其是在後台cli模式下處理大量資料或執行後台demon守護程序時，多程序的優勢不用多說。php的多執行緒也曾被人提及，但程序內多執行緒資源共享和分配的問題難以解決...

初探PHP多程序

我們都知道php是單程序執行的，php處理多併發主要是依賴伺服器或php fpm的多程序及它們程序的復用，但php實現多程序也意義重大，尤其是在後台cli模式下處理大量資料或執行後台demon守護程序時，多程序的優勢不用多說。php的多執行緒也曾被人提及，但程序內多執行緒資源共享和分配的問題難以解決...

初探PHP多程序

body blog calendar p,blockquote,ul,ol,dl,table,pre h1,h2,h3,h4,h5,h6 h1 tt,h1 code,h2 tt,h2 code,h3 tt,h3 code,h4 tt,h4 code,h5 tt,h5 code,h6 tt,h6 co...