Devel::STrace::Monitor

# Devel::STrace

Description | strace for Perl scripts

Devel::STrace > Package Manuals > Devel-STrace-Monitor
Classdocs

### Index

- NAME
- SYNOPSIS
- DESCRIPTION
- METHODS
- SEE ALSO
- AUTHOR, COPYRIGHT, AND LICENSE

# NAME

Devel::STrace::Monitor - Monitor interface component for Devel::STrace

# SYNOPSIS

        #
        #    open the mmap'ed file
        #
        use Devel::STrace::Monitor;

        my $view = Devel::STrace::Monitor->open('somefile.map');

        my $cycles = 0;
        while (1) {
            print "\n**************************************\n";
        #
        #    refresh the internal ringbuffer map
        #
            $view->refresh();
        #
        #    dump the current traces
        #
            $view->trace(\&dump_trace);

            sleep 10;
        }
        #
        #    method to display the traces
        #
        sub dump_trace {
            my ($key, $slot, $depth, $line, $time, $entry) = @_;

            $lastkey = $key,
            print "\n**************************************\n"
                unless ($lastkey eq $key);

            if ($time) {
        #
        #    trim the weekday and year from timestamp
        #
                my $frac = ($time - int($time)) * 1000000;
                $frac=~s/\..*$//;
                my @parts = split(/\s+/, scalar localtime($time));
                pop @parts;    # get rid of year
                print "$key($depth) : $slot : $entry:$line at ",
                    join(' ', @parts), '.', $frac, "\n";
            }
            else {
                print "$key($depth) : $slot : $entry:$line (No timestamp)\n";
            }
        }

# DESCRIPTION

Provides methods to

- attach to and read the memory mapped file generated by Devel::STrace (or future full featured debuggers) using Devel::RingBuffer.
- set or clear any of the `$DB::single`, `$DB::trace`, or `$DB::signal` control variables of the AUT (via their tie'd interfaces in the AUT).
- inspect the current execution call stack of the AUT

The interfaces provide a simple framework for building an external application that can attach to a running Perl application, monitor its current execution, and eventually detach, all while permitting the application continue to run uninterrupted.

A more complete debugger module is planned to exploit the various command/control structures available via Devel::RingBuffer. Note that this module will be fully compatible with the resulting debugger so that, e.g., an application can first be monitored to detect troublespots, and then the debugger can be attached to fully debug the problem.

# METHODS

Refer to the include classdocs for summary and detail method descriptions.

# SEE ALSO

Devel::STrace

Devel::RingBuffer

IPC::Mmap

`plstrace.pl` is a simple command line script using this module.

# AUTHOR, COPYRIGHT, AND LICENSE

Dean Arnold mailto:darnold@presicient.com

Copyright(C) 2006, Dean Arnold, Presicient Corp., USA. All rights reserved.

Permission is granted to use this software under the same terms as Perl itself. Refer to the Perl Artistic License for details.