StopWatch Class Reference

This class is used to determine the current process' CPU (user and/or kernel) and wall time. More...

#include <OpenMS/SYSTEM/StopWatch.h>

Collaboration diagram for StopWatch:

Classes
struct	TimeDiff_

Public Member Functions
void	start ()
	Start the stop watch. More...
void	stop ()
	Stop the stop watch (can be resumed later). If the stop watch was not running an exception is thrown. More...
void	resume ()
	Resume a stopped StopWatch. More...
void	reset ()
	Clear the stop watch but keep running. More...
void	clear ()
Readout of the StopWatch
double	getClockTime () const
double	getUserTime () const
double	getSystemTime () const
double	getCPUTime () const

Predicates
typedef clock_t	TimeType
static const PointerSizeInt	cpu_speed_
	POSIX API returns CPU ticks, so we need to divide by CPU speed. More...
TimeDiff_	accumulated_times_
TimeDiff_	last_start_
	point in time of last start() More...
bool	is_running_ = false
	state of stop watch, either true(on) or false(off) More...
bool	isRunning () const
bool	operator== (const StopWatch &stop_watch) const
bool	operator!= (const StopWatch &stop_watch) const
bool	operator< (const StopWatch &stop_watch) const
bool	operator<= (const StopWatch &stop_watch) const
bool	operator>= (const StopWatch &stop_watch) const
bool	operator> (const StopWatch &stop_watch) const
String	toString () const
	get a compact representation of the current time status. More...
static String	toString (const double time_in_seconds)
TimeDiff_	snapShot_ () const
	get the absolute times for current system, user and kernel times More...

Detailed Description

This class is used to determine the current process' CPU (user and/or kernel) and wall time.

CPU time is measured as sum of all threads of the current process.

To read a time, the stopwatch must be started beforehand, but not necessarily stopped.

You can stop() the timer and resume() it later to omit intermediate steps which should not count towards the measured times.

Member Typedef Documentation

TimeType

typedef clock_t TimeType

private

Member Function Documentation

clear()

void clear

(

)

Clear and stop the stop watch. This sets the stop watch to zero and stops it when running.

See also

reset

getClockTime()

double getClockTime

(

)

const

Get clock time. Return the accumulated wall clock (real) time in seconds.

Referenced by main().

getCPUTime()

double getCPUTime

(

)

const

Get CPU time. Return the accumulated CPU time in seconds. CPU time is the sum of user time and system time across all threads.

getSystemTime()

double getSystemTime

(

)

const

Get user time. Return the accumulated system time in seconds across all threads.

getUserTime()

double getUserTime

(

)

const

Get user time. Return the accumulated user time in seconds across all threads.

isRunning()

bool isRunning

(

)

const

Return true if the stop watch is running.

Returns

bool true if the stop watch is running, false otherwise

operator!=()

bool operator!=

(

const StopWatch &

stop_watch

)

const

Inequality operator. Return false if two stop watches differ in any way, i.e. they differ in either the clock, user, or system time or have a different running status.

Parameters

stop_watch

the stop watch to compare with

Returns

bool true on inequality, false otherwise

operator<()

bool operator<

(

const StopWatch &

stop_watch

)

const

Lesser than operator. Return true, if the stop watch is in all timings lesser than the stop watch to be compared with (clock, user and system time).

Parameters

stop_watch

the stop watch to compare with

Returns

bool true if all times are lesser

operator<=()

bool operator<=

(

const StopWatch &

stop_watch

)

const

Lesser or equal operator. Return true, if the stop watch is in all timings lesser or equal than the stop watch to be compared with (clock, user and system time).

Parameters

stop_watch

the stop watch to compare with

Returns

bool true if all times are lesser or equal

operator==()

bool operator==

(

const StopWatch &

stop_watch

)

const

Equality operator. Return true if two stop watches are equal, i.e. they contain exactly the same time intervals for clock, user and system time and have the same running status.

Parameters

stop_watch

the stop watch to compare with

Returns

bool true on equality, false otherwise

operator>()

bool operator>

(

const StopWatch &

stop_watch

)

const

Greater operator. Return true, if the stop watch is in all timings greater than the stop watch to be compared with (clock, user and system time).

Parameters

stop_watch

the stop watch to compare with

Returns

bool true if all times are greater

operator>=()

bool operator>=

(

const StopWatch &

stop_watch

)

const

Greater or equal operator. Return true, if the stop watch is in all timings greater or equal than the stop watch to be compared with (clock, user and system time).

Parameters

stop_watch

the stop watch to compare with

Returns

bool true if all times are greater or equal

reset()

void reset

(

)

Clear the stop watch but keep running.

The stop watch is reset to 0, but not stopped (if running).

See also

clear

resume()

void resume

(

)

Resume a stopped StopWatch.

Exceptions

Exception::Precondition

if the StopWatch is already running

snapShot_()

TimeDiff_ snapShot_ ( ) const

private

get the absolute times for current system, user and kernel times

start()

void start

(

)

Start the stop watch.

Starting, Stopping and Resetting the stop watch

If the watch holds data from previous measurements, these will be reset before starting up, i.e. it is not possible to resume by start(), stop(), start(). Use resume(), stop(), resume() instead.

Exceptions

Exception::Precondition

if the StopWatch is already running

Referenced by main().

stop()

void stop

(

)

Stop the stop watch (can be resumed later). If the stop watch was not running an exception is thrown.

Exceptions

Exception::Precondition

if the StopWatch is not running

Referenced by main().

toString() [1/2]

String toString

(

)

const

get a compact representation of the current time status.

The output will be something like: 2.10 s (wall), 1.67 s (CPU), 0.12 s (system), 1.54 s (user)

toString() [2/2]

static String toString ( const double  time_in_seconds )

static

custom string formatting of time, using only the minimal number of units required (e.g., does not report hours when seconds suffice).

Member Data Documentation

accumulated_times_

TimeDiff_ accumulated_times_

private

currently accumulated times between start to stop intervals (initially 0), not counting the currently running interval which started at last_start_

cpu_speed_

const PointerSizeInt cpu_speed_

staticprivate

POSIX API returns CPU ticks, so we need to divide by CPU speed.

is_running_

bool is_running_ = false

private

state of stop watch, either true(on) or false(off)

last_start_

TimeDiff_ last_start_

private

point in time of last start()