Re: iThread + Tk

[Aashish Chaudhary]

Hi all, 

Now I was able to make the same error in the small Perl + Perl/Tk code. 

if I dont do detach here 
   my $thr = threads->new(\&run)->detach;
then this program will eat memory and as I used it here I got this error 
  Free to wrong pool 1c7a920 not 224f08 at  .../Tk/Widget.pm line 98
during global destruction.

What I am doing wrong and what does this error means ?? 

Any help is appreciated. 

Thanks, 
aashish




    #!/usr/bin/perl -w
        
    #// warning: this app kills the cpu somewhat dead, needs a more
    #// sensitive sleep in mainloop handle with care on slow machines,
threads-> yield
    #// makes it a bit lighter but still, use caution
    
    use strict;
    use Tk;
    use threads;
    use threads::shared;
    use POSIX;
    
    #// For debugging 
    $|=1;
    
    #// Constructing a new window
    my $mw = new MainWindow('title'=>"Tiitel");    
    my $clockdisplay = $mw->Label;
    $clockdisplay->pack('-side'=>'top');
    
    #// For changing the clock value ;-)
    my $clockstr : shared ;
    $clockstr = 0; 
    
    #// indicates when to stop
    my $running : shared = 1;
    
    #// starting the other thread which should change our title       
    clocker();
    predixLoop();
    
    #// This loops the tk events and refreshes the window inner things
like buttons etc.
    #// it blocks until the window is closed    
    #// program ending ;0
    #$running = 0;        
    #// SUBS    
    #// the main thread loop tries to handle event, DoOneEvent(2) means that 
    #// any action should be takin (from tcl.h) TCL_DONT_WAIT 
    #// or smth like that , exits the same way as Tk::MainLoop
    
    sub predixLoop {        
            my $oldclockval = "0";
            while(Tk::MainWindow->Count) {
                    Tk->DoOneEvent(2);              
                    # nice                     
                    if ($clockstr != $oldclockval) {
                            $oldclockval = $clockstr;
                            $clockdisplay->configure('-text'=>$oldclockval);
                    }                    
                    threads->yield();
            }
    }
    
    # the child thread running loop
    # updates the clock after every 1 sec
    sub clocker {
            print "clocker starting \n";    
            if($running)
            {
                    print " I am running: \n";
                    $running = 0;                                            
                    my $thr = threads->new(\&run)->detach;
                    print  " After the thread is created: \n";
            }
            print "child out \n";
    }
    
    sub run
    {
        my $count = 0;
        while($count ne 10){            
            print " The count is: ".($count)."\n";
            $clockstr = time();
            $count = $count + 1;
            sleep(1);
            threads->yield();            
        }        
        print " This thread will exit: \n";
        lock $running;
        $running = 1;        
    }