PHASTA/Creating Timers

This is a page to document how to create timers in PHASTA. Timers are ways of precisely timing how long a specific part of code takes to execute while having a very low overhead when doing so.

Also see PHASTA#Timings for information on reading the timers section of the PHASTA output log.

Code Changes

There are several places where code needs to change (all paths relative to [phasta git repository]/phSolver/:

• common/common.h
  • Place definitions of variables to be used for Fortran
• common/common_c.h
  • Ditto, but for C/C++
• common/new_interface.c
  • Where the timer information gets printed out to the log
• {in,}commpressible/itrdrv.f
  • Where the variables tracking the timers get reset
• Whatever code you want to time will need to be modified

common/common.h

Simply need to add a r* and/or i* variable to the mpistats, where the r stands for a real number and the i is for an integer.

The real numbers are used to track the actual time it takes to run a specific piece of code, while the integer values are used to track how many times a piece of code can be run.

common/common_c.h

Add the same variables you added to common/common.h to the mpistats struct. Note that capitalization doesn't matter in Fortran, but does in C/C++.

common/new_interface.c

Add a print statement to the print_mpi_stats function. You can simply copy/paste an example