stir::HighResWallClockTimer Class Reference

High-resolution timer. More...

#include "stir/HighResWallClockTimer.h"

Public Member Functions
	HighResWallClockTimer (void)
	Create a timer. More...
virtual	~HighResWallClockTimer (void)
	Destroy a timer. More...
void	start (bool bReset=false)
	Start a timer. More...
void	stop (void)
	Stop a running timer. More...
void	reset (void)
	Reset a timer. More...
bool	is_running (void)
	Check if a timer is running. More...
int	get_sec (void)
	Returns the number of whole seconds elapsed. More...
int	get_nanosec (void)
	Returns the number of nanoseconds that elapsed on top of whatever get_sec() returned. More...
double	value (void)
	Returns the elapsed time (in seconds) More...

Static Public Member Functions
static int	get_resolution_in_nanosecs (void)
	Attempts to guess the timer resolution. More...

Detailed Description

High-resolution timer.

This timer measures wall-clock time. Implementation is OS specific to try to use high-resolution timers. It is not derived from stir::Timer to avoid the overhead of calling a virtual function.

Typical usage:

HighResWallClockTimer t;
t.start();
do_something();
t.stop();
cout << "do_something took " << t.value() << " seconds" << endl;
t.start();
do_something_else();
t.stop();
cout << "total wall-clock time: " << t.value() << " seconds" << endl;

You have to call stop() before getting the value. You have to call reset() if you wish to use the same timer to measure several separate time intervals, otherwise the time will be accumulated.

Constructor & Destructor Documentation

HighResWallClockTimer()

stir::HighResWallClockTimer::HighResWallClockTimer ( void  )

inline

Create a timer.

The timer is not started, and elapsed time is set to zero.

References reset().

~HighResWallClockTimer()

stir::HighResWallClockTimer::~HighResWallClockTimer ( void  )

inlinevirtual

Destroy a timer.

The timer must not be running.

Member Function Documentation

start()

void stir::HighResWallClockTimer::start ( bool  bReset = false )

inline

Start a timer.

Parameters

bReset

indicates whether the elapsed time should be reset before the timer is started. The timer must not be running if asking to reset.

References reset().

Referenced by distributed::receive_and_construct_exam_and_proj_data_info_ptr(), distributed::receive_and_construct_viewgram(), distributed::receive_and_initialize_projectors(), distributed::receive_and_set_image_parameters(), distributed::receive_bool_value(), distributed::receive_double_values(), distributed::receive_image_values_and_fill_image_ptr(), distributed::receive_int_value(), distributed::receive_int_values(), distributed::receive_string(), distributed::reduce_output_image(), distributed::reduce_received_output_image(), stir::GeometryBlocksOnCylindricalTests::run_tests(), stir::BlocksTests::run_tests(), distributed::send_bool_value(), distributed::send_double_values(), distributed::send_exam_and_proj_data_info(), distributed::send_image_estimate(), distributed::send_image_parameters(), distributed::send_int_value(), distributed::send_int_values(), distributed::send_string(), distributed::send_viewgram(), and stir::ScatterSimulation::set_use_cache().

stop()

void stir::HighResWallClockTimer::stop ( void  )

inline

Stop a running timer.

When a timer is stopped (=not running), get_sec(), get_nanosec(), and value() can be used to obtain elapsed time.

Referenced by distributed::receive_and_construct_exam_and_proj_data_info_ptr(), distributed::receive_and_construct_viewgram(), distributed::receive_and_initialize_projectors(), distributed::receive_and_set_image_parameters(), distributed::receive_bool_value(), distributed::receive_double_values(), distributed::receive_image_values_and_fill_image_ptr(), distributed::receive_int_value(), distributed::receive_int_values(), distributed::receive_string(), distributed::reduce_output_image(), distributed::reduce_received_output_image(), stir::GeometryBlocksOnCylindricalTests::run_tests(), stir::BlocksTests::run_tests(), distributed::send_bool_value(), distributed::send_double_values(), distributed::send_exam_and_proj_data_info(), distributed::send_image_estimate(), distributed::send_image_parameters(), distributed::send_int_value(), distributed::send_int_values(), distributed::send_string(), distributed::send_viewgram(), and stir::ScatterSimulation::set_use_cache().

reset()

void stir::HighResWallClockTimer::reset ( void  )

inline

Reset a timer.

Sets the elapsed time to zero. The timer must not be running.

Referenced by HighResWallClockTimer(), distributed::receive_and_construct_exam_and_proj_data_info_ptr(), distributed::receive_and_construct_viewgram(), distributed::receive_and_initialize_projectors(), distributed::receive_and_set_image_parameters(), distributed::receive_bool_value(), distributed::receive_double_values(), distributed::receive_image_values_and_fill_image_ptr(), distributed::receive_int_value(), distributed::receive_int_values(), distributed::receive_string(), distributed::reduce_output_image(), distributed::reduce_received_output_image(), stir::BlocksTests::run_tests(), distributed::send_bool_value(), distributed::send_double_values(), distributed::send_exam_and_proj_data_info(), distributed::send_image_estimate(), distributed::send_image_parameters(), distributed::send_int_value(), distributed::send_int_values(), distributed::send_string(), distributed::send_viewgram(), and start().

is_running()

bool stir::HighResWallClockTimer::is_running ( void  )

inline

Check if a timer is running.

Returns true if the timer is running, or false otherwise

get_sec()

int stir::HighResWallClockTimer::get_sec ( void  )

inline

Returns the number of whole seconds elapsed.

The timer must not be running

Referenced by value().

get_nanosec()

int stir::HighResWallClockTimer::get_nanosec ( void  )

inline

Returns the number of nanoseconds that elapsed on top of whatever get_sec() returned.

The timer must not be running

Referenced by value().

value()

double stir::HighResWallClockTimer::value ( void  )

inline

Returns the elapsed time (in seconds)

The timer must not be running

References get_nanosec(), and get_sec().

Referenced by distributed::receive_and_construct_exam_and_proj_data_info_ptr(), distributed::receive_and_construct_viewgram(), distributed::receive_and_initialize_projectors(), distributed::receive_and_set_image_parameters(), distributed::receive_bool_value(), distributed::receive_double_values(), distributed::receive_image_values_and_fill_image_ptr(), distributed::receive_int_value(), distributed::receive_int_values(), distributed::receive_string(), distributed::reduce_output_image(), distributed::reduce_received_output_image(), stir::BlocksTests::run_tests(), distributed::send_bool_value(), distributed::send_double_values(), distributed::send_exam_and_proj_data_info(), distributed::send_image_estimate(), distributed::send_image_parameters(), distributed::send_int_value(), distributed::send_int_values(), distributed::send_string(), distributed::send_viewgram(), and stir::ScatterSimulation::set_use_cache().

get_resolution_in_nanosecs()

int stir::HighResWallClockTimer::get_resolution_in_nanosecs ( void  )

inlinestatic

Attempts to guess the timer resolution.

get_resolution_in_nanosecs() is by no means accurate. The only thing that is guranteed is that timer resolution is not less than the value returned by get_resolution_in_nanosecs().

On Win32, returns more or less precise resolution (can be slightly rounded if the actual resolution can't be expressed as an integer number of nanoseconds)

Returns

Estimated timer resolution (in nanoseconds)

---

The documentation for this class was generated from the following file:

• /home/sirfuser/devel/STIRdistrib/STIR/src/include/stir/HighResWallClockTimer.h