gistfile1.txt

#!/usr/bin/python3

import os
import signal
import sys
import time

def signal_handler(signum, _frame) -> None:
    if signum == 10:
        return

    sys.exit()

num_children = 2
pids = []
for _ in range(num_children):
    read_pipe, write_pipe = os.pipe()
    pid = os.fork()

    if pid == 0:
        # Child process
        os.close(write_pipe)
        signal.signal(signal.SIGUSR1, signal_handler)

        # Block on reading from the pipe
        while True:
            data = os.read(read_pipe, 1)
            print(f"read() returned {data}")
            if data == b'':
                sys.exit()

            time.sleep(1)
    else:
        # Parent process
        pids.append(pid)

# Parent process
os.close(read_pipe)

time.sleep(1)  # give some time to children to setup signal handler

start = time.time()
while time.time() < start + 120:
    for pid in pids:
        os.kill(pid, signal.SIGUSR1)

    time.sleep(0.1)

for pid in pids:
    os.kill(pid, signal.SIGTERM)