Fellow Monks
I discovered what I assumed to be a memory leak in an application I am writing using CGI::Application as a base. Initially I blamed my OO style - believing that some references were circular but this turned out to be untrue (I think).

The problem arises when using CGI::Application to return data to the browser. I used the following as a method to deliver images. 

sub getimage {
 my $self = shift;
 my $stuff = shift;
 # Set the correct header
 $self->header_props( -type=>$stuff->{mime} );
 open ( IMAGE , $stuff->{image} ) or die "Screaming $!";
 return join '', <IMAGE>;
}

[download]

Which functioned beautifully (once PodMaster slapped some sense into me regarding returning scalars to CGI:Application) however my httpd processes grew at an alarming rate. For every 1Mb image served , httpd grows by a larger amount.


Clean startup 
  PID USER     PRI  NI  SIZE  RSS SHARE STAT %CPU %MEM   TIME COMMAND
18388 root      15   0  2848 2848  2736 S     0.0  0.5   0:00 httpd
18389 vvr       18   0  2836 2836  2716 S     0.0  0.5   0:00 httpd
18390 vvr       18   0  2836 2836  2716 S     0.0  0.5   0:00 httpd

After serving one 6.2Mb image 
  PID USER     PRI  NI  SIZE  RSS SHARE STAT %CPU %MEM   TIME COMMAND
18388 root      15   0  2848 2848  2736 S     0.0  0.5   0:00 httpd
18389 vvr       15   0 31940  31M  2372 S     0.0  6.2   0:00 httpd
18390 vvr       18   0  2836 2836  2716 S     0.0  0.5   0:00 httpd

The resident memory size has grown from under 3Mb to over 31Mb. Almost 5 times the size of the data actually served. I am most curious to hear from anyone who has experienced similar behaviour (with CGI::Application especially).

This is occuring on a RH7.3 system, using apache1.3.26 and mod_perl 1.27. Below is the smallest case that exhibits this behaviour.

#!/usr/bin/perl -w
# foo.pm , to be executed by Apache
package foo;
use strict;
use base 'CGI::Application';
use CGI::Carp;

sub handler {
 warn "## handler";
 my $request = shift;
 my $app = foo->new();
 $app->run();
 exit;
}

sub setup {
 warn "## setup";
 my $self = shift;
 $self->run_modes(
  start=>'start'
 );
}


sub start {
 warn "## start";
 my $self = shift;
 open ( FH , '/path/to/some/image' ) or confess $!;
 $self->header_props( -type=>'your/mimetype' );
 return join '' , <FH>;
}


1;

[download]

httpd.conf
PerlModule Apache
PerlModule foo

<Location /testleak/>
 SetHandler perl-script
 PerlHandler foo
</Location>

[download]

If you've solved this before, or think you can see where I have done something bass-ackwards please let me know.


Many Thanks -
toaster.

I can't believe it's not psellchecked

In reply to CGI::Application + mod_perl =|!= memory leak by submersible_toaster

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.