Re^7: Execute a sub in the background

[chessgui]

I did some research on this because I run chess engines which may get out of hand. I was wondering if I can kill a handler thread when the engine freezes. It is far from being natural and easy. From what I've read I gathered that 'killing' threads from the outside is a thing you should avoid. I personally use the Tk event loop for event driven programming. I only use threads for shepherding processes which are started once and run all the way long paralelly with the MainLoop. Normally there is no need to 'kill' such a thread.

[egzoti4en]

Ok i understand. So is there a way to share a variable or maybe to sent a reference to the sub.

What i want is to have a flag in the main process when its value is one the cycle in the thread to end. How can i do this. I checked the threads::schared but honestly i wasn't able to do anything. So if you could help me whit some example code it would be great

[chessgui]

Experts will tell you to use Thread::Queue. I have not much experience with queues. However this is what you can achieve with shared variables:

use threads;
use threads::shared;

my ($global):shared;

my $handler=threads->create(\&handler)->detach;

do
    {
    
    print "Enter a value for shared global variable ( x = exit ): ";ch
+omp($global=<>);
    
    sleep(3);
    
    } while($global ne 'x');

sub handler
{

my $global_old=$global;

while(1)
    {

    if($global ne $global_old)
        {
        
        print "User changed the global variable to '$global'.\n";
        $global_old=$global;
        
        }

    sleep(1);

    }

}