JANA2
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JPerfMetrics Class Reference

JPerfMetrics represents the highest-level metrics we can collect from a running JProcessingTopology. More...

#include <JPerfMetrics.h>

Public Types

enum  Mode {
  Reset,
  Ticking,
  Stopped
}
 

Public Member Functions

Mode get_mode ()
 
void reset ()
 Reset is meant to be called between separate run()s or scale()s. More...
 
void start (size_t current_thread_count)
 This implementation of start() assumes that no processing has occurred while the stopwatch wasn't running. More...
 
void start (size_t current_event_count, size_t current_thread_count)
 This is the preferred implementation of start(), which doesn't make dangerous assumptions about nothing happening in the meantime.
 
void split (size_t current_event_count)
 Split accumulates another (monotonic) event count measurement. More...
 
void stop (size_t current_event_count)
 Stop, and record the final measurement at that time. More...
 
void stop ()
 Stop without recording a final measurement. More...
 
void summarize (JPerfSummary &summary)
 

Detailed Description

JPerfMetrics represents the highest-level metrics we can collect from a running JProcessingTopology.

Conceptually, it resembles a stopwatch, which is meant to be reset when the thread count changes, started when processing starts, split every time a performance measurement should be made, and stopped when processing finished. At each interaction the caller provides the current event count. Timers are all managed internally.

Member Function Documentation

void JPerfMetrics::reset ( )

Reset is meant to be called between separate run()s or scale()s.

It sets everything in the metric back to zero or now(), except the start_event_count, which increases monotonically throughout the life of the program.

void JPerfMetrics::split ( size_t  current_event_count)

Split accumulates another (monotonic) event count measurement.

If the stopwatch has already been stopped, split will update the event count without updating the time. This is convenient because we sometimes don't have access to the current event count but still wish to stop the timer, but it is dangerous because it makes the caller responsible for ensuring that further events don't get processed after the stopwatch stops.

void JPerfMetrics::start ( size_t  current_thread_count)

This implementation of start() assumes that no processing has occurred while the stopwatch wasn't running.

Thus it can reuse the event count from the previous run. This is convenient because that value can be annoying to calculate.

void JPerfMetrics::stop ( size_t  current_event_count)

Stop, and record the final measurement at that time.

This should be used instead of void stop() whenever possible.

void JPerfMetrics::stop ( )

Stop without recording a final measurement.

This can be provided in a later call to split(). void stop(current_event_count) is preferred.

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