Concurrent sub-routines in Perl

Question

I am attempting to get these two sub-routines running concurrently. When I fire the program I end up with:

Perl exited with active threads:
    2 running and unjoined
    0 finished and unjoined
    0 running and detached

Nothing gets print onto console. I was expected while(1) to stay active until SIGTERM.

Thread

use threads;

my $t1 = threads->create( \&sub2 );
my $t2 = threads->create( \&sub1 );

sub sub2 {
   my $dbh = get_connector();
   while (1) {
      print "Worker 2 Running";
      sleep 2;
   }
}

sub sub1 {
   while (1) {
      print "Worker 1 Running";
      sleep 1;
   }
}

Can you spot the defect here!

Doesn't solve the issue but I can spot one defect...your code doesn't compile. You're missing a semicolon after the `print` in `sub1` — ThisSuitIsBlackNot, Oct 16 '13 at 17:54
Possible duplicate of [this question](http://stackoverflow.com/questions/2949967/perl-running-simultaneous-routines). use strict; use warnings; — mikew, Oct 16 '13 at 17:58
@ThisSuitIsBlackNot It was typo while constructing this post. Nice spot though! ;-) — Bitmap, Oct 16 '13 at 18:03

ikegami · Accepted Answer · 2013-10-16T18:11:23.983

4

You never wait for the children to end before exiting the process. Add

$_->join for threads->list;

edited Oct 16 '13 at 18:11

answered Oct 16 '13 at 17:59

ikegami

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score 2 · Answer 2 · answered Oct 16 '13 at 17:56

2

Set

$| = 1;

to have unbuffered output, and make sure that your main thread does something while other thread are executing, ie.

sleep 1 while 1;

or wait for threads as @ikegami suggested

$_->join for $t1, $t2;

answered Oct 16 '13 at 17:56

mpapec

50,217
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67
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Concurrent sub-routines in Perl

Thread

2 Answers2