Re: Advice: Async Options for fire-and-forget subroutine

[Your Mother]

If you don't even care about return values, why not just use fork. You might need to be careful not to accidentally forkbomb yourself. Look at something like Parallel::ForkManager to throttle the forking if you want more control or your jobs might come in overwhelming numbers.

[mwb613]

Thanks Mom!

If I were a dumb person who'd never run any sort of forking before, should I just use fork? I also see forks, perlfork, many modules including the one you listed in your post. It sounds like, based on some of the things I'm reading, that my use case -- firing and forgetting -- will create zombies which I do not want considering it will be part of a long running process.

Also, just to clarify, the pid returned by fork() is the system PID (I'm running RHEL) or a Perl specific PID? If the former I could potentially stash the PIDs and kill them from a whole other process, no?

[Your Mother]

Untested simplistic pseudocode that ignores a potential error point (0 == fork() is for the child side of the fork and it's not tested here). Forked processes are regular processes on *nix, just children of the original program.

$SIG{CHLD} = "IGNORE";
while ( program_should_be_running() )
{
    # Might want a sleep or a usleep (from Time::HiRes) here.
    if ( my $pid = fork )
    {
        # Do nothing...? This is the "permanent" parent process.
        # $pid is the child $$
    }
    else
    {
        run_your_sub(); # Processes could stack up fast.
    }
}