ibis.constellation

Interface Timer

public interface Timer

The Timer interface provides user-access to the timing mechanism used internally in constellation. Applications can create Timers through Constellation.getTimer() or Constellation.getTimer(String, String, String). Of particular interest is the so-called "overall timer", to be accessed by Constellation.getOverallTimer(), and to be started when the application starts and stopped when the application finishes. A Timer records various times, such as queued, submitted, start, stop (similar to openCL events), but usually only start and stop are used. Each timer event also has associated with it a device name (for instance "java" or "gtx480"), a thread name (usually the executor identifier), and an action name, for instance "initialize" or "process". Constellation uses some properties to control the behavior of the timers. The ConstellationProperties.PROFILE property controls the timing. When the ConstellationProperties.PROFILE_ACTIVITY is set timings will be provided for, a.o., the invocations of Activity.initialize(ibis.constellation.Constellation) and Activity.process(ibis.constellation.Constellation, ibis.constellation.Event). In the end, the timing events will be written to a file specified with the ConstellationProperties.PROFILE_OUTPUT property, or to System.out.

Method Summary

Modifier and Type	Method and Description
void	add(long start, long end) Adds a completed event to the Timer.
void	add(java.lang.String device, java.lang.String thread, java.lang.String action, long queued, long submitted, long start, long end) Adds a completed event to the Timer.
double	averageTimeVal() Returns the average time recorded for events in this Timer, in microseconds.
int	nrTimes() Returns the number of events recorded for this Timer.
int	start() Starts a timer event.
void	stop(int eventNo) Stops a timer event.
double	totalTimeVal() Returns the total time recorded for events in this Timer, in microseconds.

Method Detail

start

int start()

Starts a timer event.

Returns:

the event number, to be used when the timer is stopped.

stop

void stop(int eventNo)

Stops a timer event. Unused event numbers are silently ignored.

Parameters:

eventNo - the event number.

add

void add(java.lang.String device,
         java.lang.String thread,
         java.lang.String action,
         long queued,
         long submitted,
         long start,
         long end)

Adds a completed event to the Timer. This may be useful if for instance the time values are recorded by a GPU, or come from another source. Note that the times are to be provided in nanoseconds and that, to get meaningful results with respect to other events, the provided times need to be "in sync" with System.nanoTime().

Parameters:

device - the device name

thread - the thread name

action - the action name

queued - time when event was queued, in nanoseconds

submitted - time when event was submitted, in nanoseconds

start - time when event was started, in nanoseconds

end - time when event finished, in nanoseconds

add

void add(long start,
         long end)

Adds a completed event to the Timer. This may be useful if for instance the time values are recorded by a GPU, or come from another source. Note that the times are to be provided in nanoseconds and that, to get meaningful results with respect to other events, the provided times need to be "in sync" with System.nanoTime(). This version has no separate queued or submitted time. These are assumed to be equal to the start time. The device, thread and action names are taken from the timer itself.

Parameters:

start - time when event was started, in nanoseconds

end - time when event finished, in nanoseconds

nrTimes

int nrTimes()

Returns the number of events recorded for this Timer.

Returns:

the number of events.

totalTimeVal

double totalTimeVal()

Returns the total time recorded for events in this Timer, in microseconds.

Returns:

the total time.

averageTimeVal

double averageTimeVal()

Returns the average time recorded for events in this Timer, in microseconds.

Returns:

the average time.