README.md

PlbCaseTimer

class PlbCaseTimer is a helper class to obtain high-level profiling data from a case. For more detailed profiling, tools like perf or gprof are better suited, but for a quick comparison, PlbCaseTimer might just do fine.

Use

Initialization

Initialization is simple: the constructor takes no arguments

PlbCaseTimer timer;

Custom timers can be added by calling

timer.registerCustom("foobar")

In addition, a timer named "global" is always present.

Use during simulation

Custom timers can be started and stopped at any location in the code. For instance, to measure the time spent in the LB collision and streaming, the following code might be used:

timer.registerCustom("CollideAndStream");
timer.registerCustom("OtherStuff");
timer.startGlobal();
for(plint iT=0;iT<maxIter;iT++){
  timer.start("CollideAndStream");
  lattice.collideAndStream();
  timer.stop("CollideAndStream");
  
  timer.start("OtherStuff");
  /* do other stuff */
  timer.stop("OtherStuff");
}
timer.stopGlobal();

This creates two timers, "CollideAndStream" and "OtherStuff", on top of the predefined timer "global". At the end of a simulation, the results can be written by calling

timer.writeLog(Parallel_ostream &out);

where Parallel_ostream is the base class of both filestreams and pcout/pcerr. A sample output could look like

Timer CollideAndStream : 36.938209 seconds, 98.57784292%
Timer Logging : 0.000134 seconds, 0.0003576088638%
Timer Output : 0.000724 seconds, 0.001932155354%
Timer Setup : 0.530791 seconds, 1.416534078%
Timer global : 37.471107 seconds, 100%
Timer other : 0.001249 seconds, 0.003333234857%

Additionally, the data can be written as a json file by calling

timer.writeLogJSON(std::string filename);

Cleanup

No cleanup is required.