Re^2: A simple web server with HTTP::Daemon and threads

[lixus]

Hello Fellows, I am really not a thread nor an OO expert but I am still wondering what is wrong with the code below.

My intention is to write a http proxy in perl. Once this is working I am going to use it to cache/serve png map tiles from e.g. www.openstreetmap.org

Why is it so slow?
Why does it stop running after a a few request?

#!/usr/bin/perl

use HTTP::Daemon;
use LWP::UserAgent;
use threads;

my $proxy = HTTP::Daemon->new( LocalPort => 3128, Listen => 20, Reuse=
+>1) || die;

while (my $conn = $proxy->accept)
{
  threads->create(\&process_one_req, $conn)->detach();
}

sub process_one_req
{
  my $conn = shift;
  my $request = $conn->get_request;
  my $ua = LWP::UserAgent->new;

  print $request->uri,"\n";

  my $response = $ua->simple_request($request);
  $conn->send_response($response);

  $conn->close;
  undef($conn);
  undef($ua);
} ## end sub process_one_req

[mrajcok]

To get the code to work reliably on Windows7 (ActiveState Perl v5.12.4) I had to add a sleep of at least 15ms after the thread creation. I use 50ms for good measure:

use Time::HiRes qw( usleep );
...
while (my $c = $d->accept) {
   threads->create(\&process_one_req, $c)->detach();
   usleep(50_000);
}

Update: after attempting AJAX POSTs with some jQuery/JavaScript, the Perl web server code was not reliable. I seemed to loose AJAX messages. (As a workaround, I installed an AJAX error handler in the JavaScript code, which performs the same AJAX POST again (well, using setTimeout)... that worked, since I can tolerate multi-second delays -- the app updates graphs that are generated only every 4 seconds.)

Update: after playing around with this some more, I was able to get reliable operation, and handle multiple browsers and multiple requests per connection/browser if I closed the client connection/socket in the server, and the daemon/server socket in the client:

use HTTP::Daemon;
use threads;

my $d = HTTP::Daemon->new(LocalAddr => $ARGV[0],
                          LocalPort => 80,
                          Reuse  => 1,
                          Listen => 20) || die;
print "Web Server started, server address: ", $d->sockhost(), ", serve
+r port: ", $d->sockport(), "\n";

while (my $c = $d->accept) {
    threads->create(\&process_client_requests, $c)->detach;
    $c->close;  # close client socket in server
}
sub process_client_requests {
    my $c = shift;
    $c->daemon->close;   # close server socket in client
    while(my $r = $c->get_request) {
        if ($r->method eq "GET") {
            my $path = $r->url->path();
            $c->send_file_response($path) or die $!;
            #or do whatever you want here
        } else { print "unknown method ".$r->method."\n" }
    }
    $c->close;
}