demo

import psutil
import multiprocessing
import socket
import sys
import concurrent.futures


ctx = multiprocessing.get_context("spawn")

def target(sock):
    with sock:
        sock.send(b"\x00")
        sock.recv(1)


def main():
    def cb():
        proc.join()
        return proc.exitcode

    with concurrent.futures.ThreadPoolExecutor() as tpe:
        while True:
            a, b = socket.socketpair()
            with a, b:
                with b:
                    proc = ctx.Process(target=target, args=(b, ))
                    proc.start()
                join_fut = tpe.submit(cb)
                assert a.recv(1) == b"\00"
                psutil_proc = psutil.Process(proc.pid)
                psutil_proc.kill()
                psutil_proc.wait()
                assert a.recv(1) == b""
                print(f"{psutil_proc=}")
                print(f"{proc=}")
                join_fut_result = join_fut.result()
                print(f"{join_fut_result=}")
                if join_fut_result is None:
                    return "broken!"


if __name__ == "__main__":
    sys.exit(main())