python 信号通信

import multiprocessing as mp 
from signal import * 
import os
from time import sleep

def saler_handler(sig,frame):
    if sig == SIGINT:
        os.kill(os.getppid(),SIGUSR1)
    elif sig == SIGQUIT:
        os.kill(os.getppid(),SIGUSR2)
    elif sig == SIGUSR1:
        print("到站了,请下车")
        os._exit(0)

def driver_handler(sig,frame):
    if sig == SIGUSR1:
        print("老司机,开车了")
    elif sig == SIGUSR2:
        print("车速有点快,系好安全带")
    elif sig == SIGTSTP:
        os.kill(p.pid,SIGUSR1)

#售票员
def saler():
    signal(SIGINT,saler_handler)
    signal(SIGQUIT,saler_handler)
    signal(SIGUSR1,saler_handler)
    signal(SIGTSTP,SIG_IGN)
    while True:
        sleep(2)
        print("Python 带你去远方")

p = mp.Process(target = saler)
p.start()

signal(SIGUSR1,driver_handler)
signal(SIGUSR2,driver_handler)
signal(SIGTSTP,driver_handler)
signal(SIGINT,SIG_IGN)
signal(SIGQUIT,SIG_IGN)
p.join()