Re: Learning to use fork()

Some progress:

my $forks = 0;
foreach my $i (1..3) {
    if ($i == 1 && fork() == 0) {
        $forks++;
        print "Running first with $$ \n";
        
        call_sub1();
        call_sub2();
        call_sub3();
        call_sub4();
        call_sub5();
        call_sub6();
        exit;
    } elsif ($i == 2 && fork() == 0) {
        $forks++;
        print "Running second $$ \n";

        call_sub1();
        call_sub10();
        call_sub3();
        call_sub13();
        call_sub5();
        
        exit;
    } else {
        if (fork() == 0) {
            $forks++;
             print "Running third with $$ \n";
            call_sub1();
            call_sub4();
            call_sub5();
            call_sub15();
            exit;
        }
    }

}

for (1 .. $forks) {
    my $pid = wait();
    print "Parent saw $pid exiting\n";
}

print "done\n";
[download]

It really feels messy and not clear. Also, it is not the most efficient because ALL of the 15 calls are not depend one on another. with that logic I can create 15 if-else statements but of course it is not readable and clear. Also, the names are not the same (and all of them gets arguments - I removed them so it will be more easy to see). How should I solve it? Also, should I kill the child process when its done by using exit?

Comment on Re: Learning to use fork() Download Code

Replies are listed 'Best First'.
Re^2: Learning to use fork() by Aldebaran (Curate) on Jan 16, 2019 at 04:59 UTC
It really feels messy and not clear. fork is fraught in perl without it really being perl's fault. I had recently endeavored to do some multitasking project that way and became convinced that the implementation is not worth the trade-offs, the first being that it must occur in an eval/die pair. My source looks about like yours, and my results were just about as unsatisfying as well. This is about where I dealt with it first: Re^2: using online translation engines with perl. Also, should I kill the child process when its done by using exit? There were a couple posts on that thread that showed how to kill the processes. I used a different way to get done what I needed.	[reply]
Re^2: Learning to use fork() (use Proc::Background) by Anonymous Monk on Jan 15, 2019 at 04:03 UTC
It really feels messy and not clear 11_42 You're really asking how to clean 11_42? 11_42 you say? What is 11_42? Exactly! 1 use Proc::Background #!/usr/bin/perl -- use strict; use warnings; use Proc::Background; my @jobs = ( [ $^X, 'job1.pl' ], [ $^X, 'job2.pl' ], [ $^X, 'job3.pl' ], [ $^X, 'job4.pl' ], [ $^X, 'job5.pl' ], [ $^X, 'job6.pl' ], [ $^X, 'job7.pl' ], [ $^X, 'job8.pl' ], [ $^X, 'job9.pl' ], [ $^X, 'job10.pl' ], [ $^X, 'job11.pl' ], [ $^X, 'job12.pl' ], [ $^X, 'job13.pl' ], ); my @procs = map { Proc::Background->new( @$_ ) } @jobs; while( @procs ){ @procs = { $_->alive ? $_ : ItsOverMaybeRestart($_) } map @procs; sleep 1; } sub ItsOverMaybeRestart { my( $proc ) = @_; ... return; } [download]	[reply] [d/l]
Re^3: Learning to use fork() (use Proc::Background) by AnomalousMonk (Archbishop) on Jan 15, 2019 at 04:51 UTC
`@procs = { $_->alive ? $_ : ItsOverMaybeRestart($_) } map @procs;` [download] I don't know anything about Proc::Background, but shouldn't that be something like `@procs = map { $_->alive ? $_ : ItsOverMaybeRestart($_) } @procs;` [download] ? Give a man a fish: `<%-{-{-{-<`	[reply] [d/l] [select]