NAME
Acme::Spork - Perl extension for spork()ing in your script
SYNOPSIS
use Acme::Spork;
my $spork_pid = spork(\&long_running_code, @ARGV)
or die "Could not fork for spork: $!";
print "Long running code has been started as PID $spork_pid, bye!\n";DESCRIPTION
A spork in the plastic sense is a fork combined with a spoon. In programming I've come to call a spork() a fork() that does more than just a fork.
I use it to describe when you want to fork() to run some long running code but immediately return to the main program instead of waiting for it.
spork()
The first argument is a code ref that gets executed and any other args are passed to the call to the code ref.
#!/usr/bin/perl
use strict;
use warnings;
use Acme::Spork;
print 1;
spork(
sub {
sleep 5;
open my $log_fh, '>>', 'spork.log', or die "spork.log open failed: $!";
print {$log_fh} "I am spork hear me spoon\n";
close $log_fh;
},
) or die qq{Couldn't fork for spork: $!};
print 2;This prints out "12" immediately and is done running, now if you tail -f spork.log you'll see "I am spork hear me spoon\n" get written to it 4 or 5 seconds later by the spork()ed process :)
spork() returns the PID of the spork()ed process so you can keep track of them and do what you need with it.
If it returns false then fork failed so you can:
if(spork(\&foo)) {
print "I am spork here me spoon\n";
}
else {
print "Could not fork for spork: $!";
}
my $spork_pid = spork(\&foo) or die "Could not fork for for spork: $!";daemonize()
Since many daemons need to spork a child process when a request is received I've included a cheat function to daemonize your script execution.
Its simply a wrapper for Proc::Daemon::Init.
use Acme::Spork qw(daemonize);
# make sure we are the only one running:
use Unix::Pid '/var/run/this.pid';
# if so make me a daemon:
daemonize();
# and redo the pid_file with the new pid
Unix::PID->new()->pid_file('/var/run/this.pid')
or die 'The PID in /var/run/this.pid is still running.';
# and handle requests as a server:
while(<$incoming_requests>) {
my $req_pid = spork(\&handle_request($_));
if($req_pid) {
spork(\&log_request($_), $req_pid)
or warn "Could not spork log request $req_pid: $!";
}
else {
warn "Could not spork request: $!";
}
}daemonize_without_close_on()
Same as daemonize() except it doesn't get Proc::Daemon::Init()'s POSIX::close done. Useful if that happening causes you problems (which it has me...)
EXPORT
spork() is by default, daemonize() and daemonize_without_close_on() can be.
SEE ALSO
Proc::Daemon is not used unless you call daemonize().
Unix::PID is not used at all in this module except the daemonize() example. I figured if you were using this module you many be interested in it as well :)
ATTN modules@perl.org
I'd love to have this registered if you could find it in your heart :)
http://www.xray.mpe.mpg.de/mailing-lists/modules/2005-12/msg00154.html
AUTHOR
Daniel Muey, http://drmuey.com/cpan_contact.pl
COPYRIGHT AND LICENSE
Copyright (C) 2006 by Daniel Muey
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.6 or, at your option, any later version of Perl 5 you may have available.