Im trying to use cond_timedwait to determine whether a given thread is 'stuck'. Im doing something wrong as I don't seem to get a timeout. 

#!/usr/bin/perl -w

use threads;
use threads::shared;

my $locked : shared;

lock( $locked );
print "locked(main)\n ";
$thr = async{ test() };
print "starting\n";
$wait = cond_timedwait( $locked, time() + 5 );

print "result: timeout\n" if ( !defined( $wait ));
print "done\n";
exit;

sub test
{
    print "started. \n";
    lock( $locked );
    print "locked(test)\n ";
    sleep( 10 );
    
    print "exiting\n";

    cond_signal( $locked );
}

[download]

Outputs the following: 
locked(main)
 starting
started.
locked(test)
 exiting
result: timeout
done

[download]
If the thread sleeps for 5 and the timer waits for 10 then it seems to signal properly and exit. Its the 'stuck' case (thread sleeps for 10, timer waits for 5) that doesn't seem to work as I would expect it to.

What am I doing wrong?

In reply to threads - cond_timedwait question by ethrbunny

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