Re^2: perl threads exiting abnormally

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) {
[download]

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