Re: perl threads exiting abnormally

[Khen1950fx]

I'd recommend that you start out working with one thread, then two, three, etc. until you get a feel for threads. I couldn't replicate your error, but then I didn't use threads the same as you. Here's a simplified script to check the number of threads enqueued:

#!/usr/bin/perl -l

BEGIN {
    $|  = 1;
    $^W = 1;
}

use strict;
use warnings;
use threads;
use Thread::Queue;
use LWP::UserAgent;

use constant THREADS => 3; 

my(@urls) = (
    'http://search.cpan.org',
    'http://www.perl.org',
    'http://www.cpan.org',
);
                  
my $workq = Thread::Queue->new;
my $thr = threads->create( sub {
    while(defined(my $url = $workq->dequeue)) {
        do {
            my $ua = LWP::UserAgent->new;
            foreach my $url (@urls) {
                my $response = $ua->get($url);
                if ($response->is_success) {
                    print $response->decoded_content;
                }
                else {
                die $response->status_line;
                }
            }
        };
    }
});

$workq->enqueue($urls[0], $urls[1], $urls[2]);

my $num_working = $workq->pending();
print $num_working;
$workq->end();
$thr->detach();
undef $thr;

[Lotus1]

• Why did you put a 'do' block inside a while loop? The while loop is going to do the block inside it anyway.

• $workq->end();

  I couldn't replicate your error.

  There is no end() method listed in the POD for Thread::Queue. Did you test this code? I got a 'Can't locate object method "end"...' warning for this line.

• $workq->enqueue($urls[0], $urls[1], $urls[2]);

  Why not this? $workq->enqueue(@urls);

• while(defined(my $url = $workq->dequeue)) {
          do {
              my $ua = LWP::UserAgent->new;
              foreach my $url (@urls) {
  

  You get $url from $workq then override it with each of the urls from @urls? Wouldn't this make each thread access every url?