print "got a strange problem"
  if mod_perl::VERSION == 1.21 and ($| or client_is_printing("\015\012
+"))
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Usually I'd bang my head onto my keyboard now, fix the real thing, and exhale... But this time I'm courious, since I found a workaround but no explanation for my problem, so I modified my post and put it on here... I was wondering whether the SOPW was the right place, or if this might be enough for some meditation -- to be on the secure side, I chose the former. Any yes, I know this is not the place to tell the story of a lifetime, but that's me... ;)

But first, let me describe my configuration:

Server: Apache 1.3.12, mod_perl 1.21, Apache::Registry 2.01 on IBM AIX 4.3
Clients: various (RedHat 7.1, SuSE 8.0, Win32)

In my httpd.conf you'll find:

<IfModule mod_perl.c>

PerlRequire /apache/advinst_test/conf/startup.pl

PerlModule Apache::StatINC

Alias /cgi-registry /apache/advinst_test/cgi-bin

   <Location /cgi-registry>
        SetHandler perl-script
        PerlHandler Apache::Registry
        Options ExecCGI
        PerlSendHeader On
        PerlInitHandler Apache::StatINC
        PerlSetVar StatINCDebug On
        order deny,allow
        allow from all
   </Location>

</IfModule>
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Now put the following script on the server (I named it echo_post_data.pl):

#!/usr/bin/perl -w

use strict;

run_server();

sub debug_post_data()
{
  warn "DEBUG: the content length is $ENV{CONTENT_LENGTH}\n";

  my $returncode = read(STDIN, my $post_content, $ENV{CONTENT_LENGTH})
+;

  warn "DEBUG: the read returncode was $returncode\n";
  warn "DEBUG: Finished.\n";
}

sub run_server()
{
  $| = 1;

    print "Content-Encoding: iso-8859-1\015\012",
          "Content-Type: text/plain\015\012",
          "\015\012";

  debug_post_data();
}
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Then put the following script on your client (I named it client_info_postdata.pl)

#!/usr/bin/perl -w

use strict;

use LWP::UserAgent;

  my $server          = shift;
  my $content_length  = shift || 1024;
  my $pattern         = shift || '#';


  my $useragent = LWP::UserAgent->new;

  my $http_request = HTTP::Request->new(POST => $server);

  $http_request->content_type('text/plain');

  $http_request->content($pattern x ($content_length / length($pattern
+)) );

  print    "\nRequest Content Length is ", length $http_request->conte
+nt,".\n";

  my $http_response = $useragent->request($http_request);

  print "\n<response>\n", $http_response->as_string, "</response>\n";
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Now do perl client_info_postdata.pl http://pacman.host.magwien.gv.at:8080/cgi-registry/echo_post_data.pl 11680 +

Everything will work fine:

Request Content Length is 11680.

<response>
HTTP/1.1 200 OK
Connection: close
Date: Fri, 30 Aug 2002 12:05:38 GMT
Server: Apache/1.3.12 (Unix) mod_perl/1.21 NTLM/2.1
Content-Encoding: iso-8859-1
Content-Type: text/plain
Client-Date: Fri, 30 Aug 2002 12:07:11 GMT
Client-Response-Num: 1
Client-Transfer-Encoding: chunked


</response>
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Then say perl client_info_postdata.pl http://pacman.host.magwien.gv.at:8080/cgi-registry/echo_post_data.pl 11681 +

If it works fine, do it a few times. You should see:

Request Content Length is 11681.
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On my setup this will hang until it times out:

<response>
500 (Internal Server Error) read timeout
Client-Date: Fri, 30 Aug 2002 12:10:36 GMT


</response>
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Apache's errlog log will show (after the timeout):

DEBUG: the content length is 11681
DEBUG: the read returncode was 11680
DEBUG: Finished. at /foo/bar/cgi-bin/echo_post_data.pl line 14.
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Note the one-byte difference? Seemingly something chomped (?) the last byte of my post data!! Who was it? Come out, Bastard!

Now for the strange part of this: If I run the same script against /cgi-bin/ (mod_cgi instead of Apache::Registry), it works fine. When I comment out $| = 1 it works fine, too. When I don't print the final "\015\012" it works too, but then I get:

Request Content Length is 11681.

<response>
500 (Internal Server Error) EOF instead of reponse status line
Client-Date: Fri, 30 Aug 2002 12:20:00 GMT


</response>
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And, much to my surprise it appears to work once whenever Apache::StatINC reloads some of my libraries I load on that server. AFAIK I don't do anything I should better not do in mod_perl, or do I? Or, did I discover something here? Is this a known bug in mod_perl 1.21 or Apache::Registry 2.01 I haven't heard know about?

It seems that I can simply leave $| off to solve my problem for now, but I'd really want my hot pipes back! I already tried chunked reading, BTW, using

sub read_post_data_chunked(;$$)
{
  my $content_length  = shift || $ENV{CONTENT_LENGTH};
  my $chunk_size      = shift || $DEFAULT_CHUNK_SIZE;

  my $raw_data;

    while($content_length > 0)
    {
      warn read(STDIN, my $chunk, $chunk_size < $content_length ? $chu
+nk_size : $content_length) . " chars read.\n";

      $raw_data       .= $chunk;
      $content_length -= $chunk_size;
    }

  return $raw_data;
}
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instead of reading in everything at once, but that didn't help. The script hung just the same (It does 2 loops than hangs in the third.

Any ideas?

Next thing I am going to do, is to look inside Apache::Registry, maybe I can find an explanation for this. I guess CORE::read is overloaded, maybe there's a glitch somewhere.

So long, Flexx

Additional Info

perl -v says:

Summary of my perl5 (5.0 patchlevel 5 subversion 3) configuration:
  Platform:
    osname=aix, osvers=4.3.1.0, archname=aix
    uname='aix hercules 3 4 00001427e800 '
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=undef useperlio=undef d_sfio=undef
  Compiler:
    cc='cc', optimize='-O', gccversion=
    cppflags='-D_ALL_SOURCE -D_ANSI_C_SOURCE -D_POSIX_SOURCE -qmaxmem=
+8192 -I/usr/local/include'
    ccflags ='-D_ALL_SOURCE -D_ANSI_C_SOURCE -D_POSIX_SOURCE -qmaxmem=
+8192 -I/usr/local/include'
    stdchar='unsigned char', d_stdstdio=define, usevfork=false
    intsize=4, longsize=4, ptrsize=4, doublesize=8
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=8
    alignbytes=8, usemymalloc=n, prototype=define
  Linker and Libraries:
    ld='ld', ldflags =' -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib /usr/ccs/lib
    libs=-lnsl -lgdbm -ldbm -ldl -lld -lm -lc -lcrypt -lbsd -lPW
    libc=, so=a, useshrplib=false, libperl=libperl.a
  Dynamic Linking:
    dlsrc=dl_aix.xs, dlext=so, d_dlsymun=undef, ccdlflags='-bE:perl.ex
+p'
    cccdlflags=' ', lddlflags='-bhalt:4 -bM:SRE -bI:$(PERL_INC)/perl.e
+xp -bE:$(BASEEXT).exp -b noentry -lc -L/usr/local/lib'


Characteristics of this binary (from libperl):
  Built under aix
  Compiled at Feb  4 2000 10:18:39
  @INC:
    /usr/local/lib/perl5/5.00503/aix
    /usr/local/lib/perl5/5.00503
    /usr/local/lib/perl5/site_perl/5.005/aix
    /usr/local/lib/perl5/site_perl/5.005
    .
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