// stopwatch tapset
// Copyright (C) 2012 Red Hat Inc.
//
// This file is part of systemtap, and is free software.  You can
// redistribute it and/or modify it under the terms of the GNU General
// Public License (GPL); either version 2, or (at your option) any
// later version.

global _stopwatch_starttime, _stopwatch_acc

/*
 * Description of the stopwatch states:
 * if (! name in _stopwatch_acc) {stopwatch doesn't exist}
 * if (_stopwatch_starttime[name] == 0 ) {stopwatch not running}
 * if (_stopwatch_starttime[name] != 0 ) {stopwatch running}
 */


/**
 * sfunction delete_stopwatch - Remove an existing stopwatch
 * @name: the stopwatch name
 *
 * Remove stopwatch @name.
 */
function delete_stopwatch (name:string)
{
	delete _stopwatch_starttime[name];
	delete _stopwatch_acc[name];
}


/**
 * sfunction start_stopwatch - Start a stopwatch 
 * @name: the stopwatch name
 *
 * Start stopwatch @name.
 * Creates stopwatch @name if it does not currently exist.
 */
function start_stopwatch (name:string)
{
	stime = _stopwatch_starttime[name]
	if (stime == 0)
		_stopwatch_starttime[name] = gettimeofday_ns()
	/* make sure there is an entry in _stopwatch_acc */
	_stopwatch_acc[name] = _stopwatch_acc[name]
}


/**
 * sfunction stop_stopwatch - Stop a stopwatch 
 * @name: the stopwatch name
 *
 * Stop stopwatch @name.
 * Creates stopwatch @name if it does not currently exist.
 */
function stop_stopwatch (name:string)
{
	stime = _stopwatch_starttime[name]

	if (stime != 0)
		delta =  gettimeofday_ns() - stime
	else
		delta = 0

	_stopwatch_starttime[name] = 0
	_stopwatch_acc[name] = _stopwatch_acc[name] + delta
}


/**
 * sfunction read_stopwatch_ns - Reads the time in nanoseconds for a stopwatch
 * @name: stopwatch name
 *
 * Returns time in nanoseconds for stopwatch @name.
 * Creates stopwatch @name if it does not currently exist.
 */
function read_stopwatch_ns:long (name:string)
{
	stime = _stopwatch_starttime[name]
	if (stime != 0)
		delta = gettimeofday_ns() - stime
	else
		delta = 0

	_stopwatch_acc[name] = _stopwatch_acc[name]
	return (_stopwatch_acc[name] + delta)
}


/**
 * sfunction read_stopwatch_us - Reads the time in microseconds for a stopwatch
 * @name: stopwatch name
 *
 * Returns time in microseconds for stopwatch @name.
 * Creates stopwatch @name if it does not currently exist.
 */
function read_stopwatch_us:long (name:string)
{
	return read_stopwatch_ns(name)/1000;
}


/**
 * sfunction read_stopwatch_ms - Reads the time in milliseconds for a stopwatch
 * @name: stopwatch name
 *
 * Returns time in milliseconds for stopwatch @name.
 * Creates stopwatch @name if it does not currently exist.
 */
function read_stopwatch_ms:long (name:string)
{
	return read_stopwatch_ns(name)/1000000;
}


/**
 * sfunction read_stopwatch_ms - Reads the time in seconds for a stopwatch
 * @name: stopwatch name
 *
 * Returns time in seconds for stopwatch @name.
 * Creates stopwatch @name if it does not currently exist.
 */
function read_stopwatch_s:long (name:string)
{
	return read_stopwatch_ns(name)/1000000000;
}
