This is Benchmark::Timer, a simple Perl code benchmarking tool.
You can install it in the typical CPAN module manner:

    % perl Makefile.PL
    % make
    % make test
    # make install

You can find the latest distribution at the following URL:

    http://www.zeuscat.com/andrew/src/Benchmark-Timer-0.5.tar.gz

You can also find it at your friendly neighborhood CPAN:

    http://www.perl.com/CPAN-local/modules/by-module/Benchmark/

Appended below is are the Changes and POD documentation from Timer.pm.

Contact Andrew Ho (andrew@zeuscat.com) with comments or bug reports.


========================================================================

Revision history for Perl extension Benchmark::Timer.

0.5 - April 20, 2001

  * Added functionality to skip trials when doing repeated trials
    via a "skip" constructor parameter, plus tests for this.
  * Consistently use croak() and carp() instead of die() and warn().
  * Add error tests to test that error conditions are properly met.
  * Renamed Benchmark::Timer object to $t in the test cases to make
    them more conventional.

0.4 - March 29, 2001

  * Changed internal method representation to an array instead of a
    hash, for a tiny but measureable speed increase.
  * Corrected timestr() to display microseconds and show integral times.
  * Added delta.pl, a small script that calculates the approximate
    overhead of using Benchmark::Timer versus plain Time::HiRes calls.

0.3 - March 26, 2001

  * Renamed Time::Timer to Benchmark::Timer after some discussion on
    the comp.lang.perl.modules newsgroup.

0.2 - March 24, 2001

  * Added $t->result, $t->results, and $t->data methods to access data.
  * warn() instead of puke when $t->report is called while an event is
    still pending (thanks Ilmari Karonen <perl@itz.pp.sci.fi>).


0.1 - March 23, 2001

  * Original version, created by Andrew Ho (andrew@zeuscat.com), rolled.


========================================================================
NAME

    Benchmark::Timer - Perl code benchmarking tool

SYNOPSIS

        use Benchmark::Timer;
        $t = Benchmark::Timer->new(skip => 1);

        for(0 .. 1000) {
            $t->start('tag');
            &long_running_operation();
            $t->stop;
        }
        $t->report;

DESCRIPTION

    The Benchmark::Timer class allows you to time portions of code
    conveniently, as well as benchmark code by allowing timings of repeated
    trials. It is perfect for when you need more precise information about
    the running time of portions of your code than the Benchmark module will
    give you, but don't want to go all out and profile your code.

    The methodology is simple; create a Benchmark::Timer object, and wrap
    portions of code that you want to benchmark with `start()' and `stop()'
    method calls. You supply a unique tag, or event name, to those methods.
    This allows one Benchmark::Timer object to benchmark many pieces of
    code.

    When you have run your code (one time or over multiple trials), you can
    obtain information about the running time by calling the `results()'
    method or print a descriptive benchmark report by calling `report()'.

    If you run your code over multiple trials, the average time is reported.
    This is wonderful for benchmarking time-critical portions of code in a
    rigorous way. You can also optionally choose to skip any number of
    initial trials to cut down on initial case irregularities.

METHODS

    $t = Benchmark::Timer->new( [options] );
        Constructor for the Benchmark::Timer object; returns a reference to
        a timer object. Takes named arguments, of which right now there is
        only one, skip, which is the number of trials (if any) to skip
        before recording timing information.

    $t->reset;
        Reset the timer object to the pristine state it started in. Erase
        all memory of events and any previously accumulated timings. Returns
        a reference to the timer object. It takes the same arguments the
        constructor takes.

    $t->start($tag);
        Record the current time so that when `stop()' is called, we can
        calculate an elapsed time. Supply a $tag which is simply a string
        that is the descriptive name of the event you are timing. If you do
        not supply a $tag, the last event tag is used; if there is none, a
        "_default" tag is used instead.

    $t->stop($tag);
        Record timing information. The optional $tag is the event for which
        you are timing, and defaults to the $tag supplied to the last
        `start()' call. If a $tag is supplied, it must correspond to one
        given to a previously called `start()' call. It returns the elapsed
        time in milliseconds. `stop()' throws an exception if the timer gets
        out of sync (e.g. the number of `start()'s does not match the number
        of `stop()'s.

    $t->report;
        Print a simple report on the collected timings to STDERR. This
        report prints the number of trials run, the total time taken, and,
        if more than one trial was run, the average time needed to run one
        trial. It prints the events out in the order they were `start()'ed.

    $t->result($event);
        Return the time it took for $event to elapse, or the mean time it
        took for $event to elapse once, if $event happened more than once.
        `result()' will complain (via a warning) if an event is still
        active.

    $t->results;
        Returns the timing data as a hash keyed on event tags where each
        value is the time it took to run that event, or the are the average
        time it took, if that event ran more than once. In scalar context it
        returns a reference to that hash. The return value is actually an
        array, so that the original event order is preserved.

    $t->data($event), $t->data;
        These methods are useful if you want to recover the full internal
        timing data to roll your own reports.

        If called with an $event, returns the raw timing data for that
        $event as an array (or a reference to an array if called in scalar
        context). This is useful for feeding to something like the
        Statistics::Descriptive package.

        If called with no arguments, returns the raw timing data as a hash
        keyed on event tags, where the values of the hash are lists of
        timings for that event. In scalar context, it returns a reference to
        that hash. As with `results()', the data is internally represented
        as an array so you can recover the original event order by assigning
        to an array instead of a hash.

BUGS

    Benchmarking is an inherently futile activity, fraught with uncertainty
    not dissimilar to that experienced in quantum mechanics.

SEE ALSO

    the Benchmark manpage, the Time::HiRes manpage, the Time::Stopwatch
    manpage, the Statistics::Descriptive manpage

AUTHOR

    Andrew Ho <andrew@zeuscat.com>

COPYRIGHT

    Copyright(c) 2000-2001 Andrew Ho.

    This library is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself.