Help-Site Computer Manuals
Software
Hardware
Programming
Networking
  Algorithms & Data Structures   Programming Languages   Revision Control
  Protocols
  Cameras   Computers   Displays   Keyboards & Mice   Motherboards   Networking   Printers & Scanners   Storage
  Windows   Linux & Unix   Mac

NAME

NAME


NAME

Debugging mod_perl Perl Internals


Description

This document explains how to debug Perl code under mod_perl.

Most of the mod_perl 1.0 debug documentation applies to mod_perl 2.0:

Detecting Hanging Processes

See Hanging Processes: Detection and Diagnostics for the explanation, but under mp2 to use signals to detect where the process is spinning, you can't use $SIG{USR2}, you have to use POSIX signals. i.e. the code becomes:


  use Carp ();

  use POSIX qw(SIGUSR2);

  my $mask      = POSIX::SigSet->new( SIGUSR2 );

  my $action    = POSIX::SigAction->new(\&tell_where_spinning, $mask);

  my $oldaction = POSIX::SigAction->new();

  POSIX::sigaction(SIGUSR2, $action, $oldaction );

  

  sub tell_where_spinning {

      Carp::confess("caught SIGUSR2!");

  };

and then:


  % kill USR2 <pid_of_the_spinning_process>

and watch for the trace in error_log.


Maintainers

Maintainer is the person(s) you should contact with updates, corrections and patches.

  • Stas Bekman <stas (at) stason.org>


Authors

  • Stas Bekman <stas (at) stason.org>

Only the major authors are listed above. For contributors see the Changes file.

Programminig
Wy
Wy
yW
Wy
Programming
Wy
Wy
Wy
Wy