python進程之間消息監控程序

外界調用向mgr進程發送消息，mgr根據不一樣消息啓動或關閉相應進程（啓動的進程，獨佔用，只啓動一個）；

如有進程程退出 則mgr向外界發出信號。

外界代碼：

#!/usr/bin/python

#

# -*- coding:utf-8 -*-

#

#

import sys

import os

import subprocess

import signal

import time

import random

def sig_usr1(signum, frame):

  print("recive sinal from process(exited)")

signal.signal(signal.SIGUSR1, sig_usr1)

cmds= ['./mgr.py']

n =1

p = subprocess.Popen( cmds,stdin=subprocess.PIPE,stderr=subprocess.PIPE,close_fds=False)

while True:

    time.sleep(1)

    ret = p.poll()

    if ret is None:

      #print("main="+str(n))

      p.stdin.write(str(n)+"\n")

      p.stdin.flush()

      p.send_signal(signal.SIGUSR1)

      n = random.randint(1, 3)

print("main exit")

管理進程

#!/usr/bin/python

#

# -*- coding:utf-8 -*-

#

import sys

import os

import time

import signal

import subprocess

import json

data = {'num': 0, 'error': 0}

def getParentID():

  p=subprocess.Popen("ps -ef|grep tt.py|grep -v grep|awk '{print $2}'",stdout=subprocess.PIPE,shell=True)

  ret = int(p.stdout.readline())

  return ret

par_id = getParentID()

print(par_id)

exe_process = 0

isRuning = True

def sig_usr1(signum, frame):

  ret = sys.stdin.readline()

  data['num'] = int(ret)

signal.signal(signal.SIGUSR1, sig_usr1)

while isRuning:

  time.sleep(1)

  print("data['num'] ="+str(data['num']))

  if exe_process == 0: #for open

    if data['num'] == 1:

      exe_process=subprocess.Popen("./a.out",close_fds=False)

    elif data['num'] == 2:

      exe_process=subprocess.Popen("./b.out",close_fds=False)

    else:

      continue

  else: #if exe_process == 0: for close

    ret = exe_process.poll()

    if ret is None:

      if data['num'] == 3:

        exe_process.terminate()

        exe_process = 0

        os.kill(par_id,signal.SIGUSR1)

    else: #if ret is None self close

      exe_process = 0

      print("end"+str(par_id))

      os.kill(par_id,signal.SIGUSR1)

print "mgr process over "

python進程通信注意問題

1）發送信號： os.kill(par_id,signal.SIGUSR1)  #注意要 import os

2）subprocess結合管道要注意，不用就不要打開，不然容易出錯

    好比p = subprocess.Popen(cmd,stdin=subprocess.PIPE,close_fds=False)

    stdin 要用到。

3）用subprocess調用Popen時候，cmd如果python腳本，要確保能編譯經過並運行。則調用，不然很差排除錯誤