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=head1 NAME
Debugging mod_perl Perl Internals
=head1 Description
This document explains how to debug Perl code under mod_perl.
Most of the L<mod_perl 1.0 debug
documentation|docs::1.0::guide::debug> applies to mod_perl 2.0:
=head2 Detecting Hanging Processes
See L<Hanging Processes: Detection and
Diagnostics|docs::1.0::guide::debug/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 C<$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 F<error_log>.
=head1 Maintainers
Maintainer is the person(s) you should contact with updates,
corrections and patches.
=over
=item *
Stas Bekman [http://stason.org/]
=back
=head1 Authors
=over
=item *
Stas Bekman [http://stason.org/]
=back
Only the major authors are listed above. For contributors see the
Changes file.
=cut
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