Dear monks,

I am having a strange issue with a code snippet I have tested in quite a few different PCs and Windows distributions (mainly XP and Vista) and has worked fine until I ran it in an ASUS single-core netbook that has Windows XP service pack 3 and fails. I am thinking there is either a `mysterious` issue with the machine :-) or there has always been a bug in my code and it simply happened to work correctly in all the other machines.

What I am essentially doing is have a Tk application that lets the user follow some steps and show some messages accordingly. In two of these steps, I am making an HTTP GET using LWP::Simple to a router and from its xml-like answer I get a couple of variables I want. Because the main graphical application needs to be run in parallel with these two functions, I am using threads.

In the netbook I am having this issue, the second HTTP get function hangs without ever returning anything; the first works fine.

Thank you in advance for any suggestions!
Athanasia

Below you may find a simplified version of my code. 
my $thread_die1 : shared;
$thread_die1 = 0;
my $thread_go1 : shared;
$thread_go1 = 0;
my $firstvar : shared;
$firstvar = '';
my $thread1 = threads->new(\&getfirst);

my $thread_die2 : shared;
$thread_die2 = 0;
my $thread_go2 : shared;
$thread_go2 = 0;
my $secondvar : shared;
$secondvar = '';
my $thread2 = threads->new(\&getsecond);

use Tk;
use Tk::TopLevel;
use utf8;
use Win32;
use LWP::Simple;
use XML::Simple;
use POSIX(":sys_wait_h");

$customfont = "verdana 8";

$mw = new MainWindow (-title => "My application");
$window_pos = "800x600+200+200";
$mw->geometry($window_pos);
$mw->resizable(0,0);
my $label = $mw->Label(-text => "Some text", -font=>$customfont)->plac
+e(-x => 200, '-y' => 170);
my $nextbutton = $mw -> Button(-text => "Next",
    -font => $customfont,
    -height => "1",
    -width => "15",
    -command =>\&allcompsscreen)
    -> place(-x => 520, '-y' => 420);

MainLoop;

sub allcompsscreen {
        my ($firsttxt, $secondtxt);
    $mw->withdraw();
    $allcomps = $mw -> Toplevel(-title => "HTTP requests");
    $allcomps->geometry($window_pos);
    $allcomps->resizable(0,0);
    $allcomps->attributes(-topmost=>1);
        my $waitmsg1 = $allcomps->Label(-text => "Waiting for first HT
+TP GET", -font=>$customfont)->place(-x => 200, '-y' => 170);
        $thread_go1 = 1;
    my $timeout = 30;
    $allcomps->update();
    while ((!defined $firstvar or $firstvar eq '') and $timeout > 0) {
        sleep 1;
            $allcomps->update();
                $timeout -=1;
    }    
        $thread_go1 = 0;
    $waitmsg1->placeForget; 
        if ($firstvar eq 'A') {
              $firsttxt = $allcomps->Label(-text => "A", -font=>$custo
+mfont)->place(-x => 200, '-y' => 170);
        }
        else {
              $firsttxt = $allcomps->Label(-text => "NOT A", -font=>$c
+ustomfont)->place(-x => 200, '-y' => 170);
         }
         $allcomps->update;
         sleep 10;
         my $waitmsg2 = $allcomps->Label(-text => "Waiting for second 
+HTTP GET", -font=>$customfont)->place(-x => 200, '-y' => 270);
        $thread_go2 = 1;
    $timeout = 30;
    $allcomps->update();
    while ((!defined $secondvar or $secondvar eq '') and $timeout > 0)
+ {
          sleep 1;
          $allcomps->update();
              $timeout -=1;
    }    
        $thread_go2 = 0;
    $waitmsg2->placeForget; 
        if ($secondvar eq 'B') {
              $secondtxt = $allcomps->Label(-text => "B", -font=>$cust
+omfont)->place(-x => 200, '-y' => 270);
        }
        else {
              my $secondtxt = $allcomps->Label(-text => "NOT B", -font
+=>$customfont)->place(-x => 200, '-y' => 270);
        }
        $thread_die1 = 1;
        $thread_die2 = 1; 
}

sub getfirst {
    my $url = "http://192.168.1.254/...";
        while(1) {
          if ($thread_go1 == 1) {
           $firstvar = &firsthttpget($url);
          }
          else {
           sleep 1;
          }
          if ($thread_die1 == 1) {
        return;
          } 
         }
}


sub getsecond {
    my $url = "http://192.168.1.254/...";
        while(1) {
          if ($thread_go2 == 1) {
           $secondvar = &secondhttpget($url);
          }
          else {
           sleep 1;
          }
          if ($thread_die2 == 1) {
        return;
          } 
         }
}

sub firsthttpget() {
    my $res;
    my $address = $_[0];
    my $xmlobj = new XML::Simple;
    $address =~s/http:\/\//http:\/\/admin:admin\@/g;
    my $httpcontent = get $address;
    if (!defined $httpcontent or $httpcontent eq '') {
        $res = -1;
    }
        else { 
        $res= $xmlobj->XMLin($httpcontent);
    }
    return $res;
}

sub secondhttpget {
    my $res;
    my $address = $_[0];
    my $xmlobj = new XML::Simple;
    $address =~s/http:\/\//http:\/\/admin:admin\@/g;
    my $httpcontent = get $address; #Here the program hangs indefinite
+ly
    if (!defined $httpcontent or $httpcontent eq '') {
        $res = -1;
    }    
    else {
         $res = $xmlobj->XMLin($httpcontent);
    }
    return $res;
}

[download]

In reply to Threads and LWP get issue in Windows by athanasia

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.