In other words, at line 37, right above the frobniz() function.

using the perl debugger I found a little bit about the problem. The output I received seems to be possibly from the thread:

Attempt to free unreferenced scalar: SV 0x43314ac, Perl interpreter: 0x41083fc a t GRRUVI-v0.45.pl line 133. at GRRUVI-v0.45.pl line 133
Attempt to free unreferenced scalar: SV 0x5f53f6c, Perl interpreter: 0x4c9c85c a t GRRUVI-v0.45.pl line 134.
at GRRUVI-v0.45.pl line 134 GLib-GObject-CRITICAL **: g_object_steal_qdata: assertion `G_IS_OBJECT (object)' failed during global destruction. at GRRUVI-v0.45.pl line 0 eval {...} called at GRRUVI-v0.45.pl line 0
GLib-GObject-CRITICAL **: g_object_unref: assertion `G_IS_OBJECT (object)' faile d during global destruction. at GRRUVI-v0.45.pl line 0

and refers to the code lines:


#################################################
#Threads
my $thread_gps = threads->new( \&gps);
my $thread_sftp = threads->new( \&sftp);

#################################################
[download]

though the output is a little strange with it referring to line zero of the program. The threads are stopped by the join command. I wonder if the threads I have are being exited incorrectly? I'm not sure what this attempt to free unreferenced scalar is?!

####################Threads####################
#-------------------GPS-------------------
sub gps {
    my $gps_device;
    while (1) {
        goto END if $die == 1;
        if ($gps_start == 1) {
            $gps_device = GPS::NMEA->new(Port => $gps, Baud => 4800);
            
            for (;;) {
                #stops the warnings in the GPS device module
                local $^W = 0;
                
                ($ns,$lat,$ew,$lon) = $gps_device->get_position;
                
                goto END if $die == 1;
                last if $gps_start == 0;
                sleep 3;
            }
            undef $gps_device;
        } else {sleep 4}
    }
    END:
}

#-------------------SFTP-------------------
sub sftp{
    $|++;
    while(1){
    
        if ( $die == 1 ){ goto END };
        if ( $sftp_start == 1 ) {
            my $seconds = 120;
            my %args = (host=>$server, user=>$username, timeout=>$seco
+nds);
            my $sftp = Net::SFTP::Foreign->new(%args);
            #$error = 1 if $sftp->error;
            
            for (;;) {
                if (defined $ns){
                    #The GPS file Functions
                    my $gps_loc = $sftp->open( "$gps_remote/$gps_file"
+ , SSH2_FXF_CREAT|SSH2_FXF_WRITE) or $sftp->error;
                    my $new_lat;
                    my $new_lon;
                        
                    #adjust the gps position into decimal
                    if ($ns eq 'S'){
                        $new_lat = "-$lat";
                    }
                    else {
                        $new_lat = $lat;
                    }
                    if ($ew eq 'W'){
                        $new_lon = "-$lon";
                    }
                    else {
                        $new_lon = $lon;
                    }
                    $sftp->write( $gps_loc, "$nick $new_lat $new_lon")
+;
                    $sftp->close( $gps_loc);
                }
                    
                #VC Base
                if ($job == 2) {
                    #Upload the uasposition file
                    $sftp->put( $uasposition_local, $uasposition_remot
+e);
                    #update the counter
                    $count_uasposition = $count_uasposition + 0.05;
            
                    #Create the attribute file
                    my $stat_final = Net::SFTP::Foreign::Attributes->n
+ew;  
                    #open the files on the server; flagged for writing
+ and creating
                    my $waytemp = $sftp->open( $waytemp_remote) or $sf
+tp->error;
                    my $wayfinal = $sftp->open( $wayfinal_remote, SSH2
+_FXF_CREAT, $stat_final) or $sftp->error;
                    #Read the stats of the files and check which is ne
+wer
                    my $stat_temp = $sftp->fstat($waytemp);
                    $stat_final = $sftp->fstat($wayfinal);
                
                    #check to see if temp is newer than final
                    if (( $stat_final->mtime) < ($stat_temp->mtime)) {
                        #Turn verification window on
                        $verify = 1 if $verify == 0;
                        if ( $verify == 2) {
                            #read the lines in then write to the wayfi
+nal file if it is newer then the waytemp file
                            my $print = $sftp->readline( $waytemp);
                            my $wayfinal = $sftp->open( $wayfinal_remo
+te, SSH2_FXF_TRUNC|SSH2_FXF_WRITE) or $sftp->error;
                            #write to the file and add to the counter 
+if it does write
                            $sftp->write( $wayfinal, $print);
                            $count_waypoint = $count_waypoint + 0.05;
                            $verify = 0;
                        }
                        if ( $verify == 3) {
                            #get time and print it to the final file
                            my $time = time;
                            $stat_final->set_amtime( $time, $time);
                            $sftp->fsetstat( $wayfinal, $stat_final);
                            $count_waypoint = $count_waypoint + 0.05;
                            $verify = 0;
                        }
                        #close the files on the server
                        $sftp->close( $waytemp);
                        $sftp->close( $wayfinal);
                    }
                }
                
                #Met Base
                if ($job == 3){
                    #Open the waytemp file on the server; for write on
+ly
                    if ( $verify == 4) {
                        my $waytemp = $sftp->open( $waytemp_remote, SS
+H2_FXF_TRUNC|SSH2_FXF_WRITE) or $sftp->error;
                        #Write the waypoints to the waytemp file
                        $sftp->write( $waytemp, $coords);
                        $sftp->close( $waytemp);
                        $count_waypoint = $count_waypoint + 0.05;
                        $verify = 0;
                    }
                }        
                sleep 1;
            }
            if($sftp_start == 0){ last};
            if($die == 1){ goto END };
            #undef $sftp;
        }else { sleep 1 }
    }
    END:
}

#################################################
[download]

An "attempt to free unreferenced scalar" basically means the perl interpreter got confused somewhere about the reference count of some object. This usually indicates a serious issue with either the interpreter itself or some of the XS/C based extensions you're using.

Given that you're using threads, it really could be either, but I would probably start by not using threads and see if the problem goes away. There really aren't many situations where threads are the best option (at least, not in perl).

"What should it profit a man, if he should win a flame war, yet lose his cool?"

Glib::Object->set_threadsafe (TRUE);
[download]

If that dosn't do it, you are probably setting up your threads improperly, and you need to show a complete working snippet to demonstrate the problem. Gtk2 tries to be better at thread clean-up than Tk, BUT it is not perfect. If you try to dynamically create threads from anywhere in your program, you are quite likely to hit problems. Your thread code contains some complex ssh and sftp code, and they may not be threadsafe, or you need to do cleanup on the ssh/sftp connection before closing the thread. Try putting simpler code in the sftp thread sub, and see if it works. Like just connect, get a dirlist, and disconnect. If it works, then start adding complexity and testing as you go.