Performance Timing Example using C API

An illustrative code example in C using the performance timer API is shown below (and is also available in the examples directory from a top-level install). This example illustrates basic timer usage (including the use of nested timers).

//-----------------------------------------------------------------------bl-
//--------------------------------------------------------------------------
// 
// libGRVY - a utility library for scientific computing.
//
// Copyright (C) 2008-2013,2018-2022 The PECOS Development Team
// Additional Copyright (C) 2018 individual authors
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the Version 2.1 GNU Lesser General
// Public License as published by the Free Software Foundation.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc. 51 Franklin Street, Fifth Floor, 
// Boston, MA  02110-1301  USA
//
//-----------------------------------------------------------------------el-
//
// Simple example illustrating performance timing via libGRVY.
//
//--------------------------------------------------------------------------
//--------------------------------------------------------------------------
 
#include<stdio.h>
#include<unistd.h>
#include<grvy.h>
#include<sys/time.h>
#include<time.h>
 
const double Foo_Sleep = 0.3 * 1.e6;
const double Bar_Sleep = 0.05 * 1.e6;
const double Boo_Sleep = 0.1167 * 1.e6;
const    int Max_Iters = 10;
 
void foo();
void bar();
void boo();
 
int main()
{
 
  int i,itest;
  const int num_repeat = 2;
 
  /* Initialize the timing library - the global timer will be
     initialized with this call */
 
  grvy_timer_init("GRVY Example Timing");
 
  /* Outer Test Loop */
 
  for(itest=0;itest<num_repeat;itest++)
    {
 
      /* Reset the timer to mearure performance timing for each test
         loop iteration  */
 
      if(itest > 0)
        grvy_timer_reset();
 
      /* Define the beginning of the overall code portion to be monitored */
 
      grvy_timer_begin("Main Program");
 
      /* Primary Iteration Work Loop */
 
      for(i=0;i<Max_Iters;i++)
        {
          printf("Main iteration loop = %i\n",i);
          foo();
        }
 
      /* Finalize the main program timer */
 
      grvy_timer_end("Main Program");
      grvy_timer_finalize();
 
      /* Print performance summary to stdout */
 
      grvy_timer_summarize();
 
    }
 
  /* Query timers directly - results should match those
     shown in grvy_timer_summarize() routine */
 
  printf("Querying global timer elapsed time:\n");
  printf("\tElapsed global time = %10.5e secs\n",grvy_timer_elapsed_global());
 
  printf("\nQuerying individual timers (exclusive values):\n");
 
  printf("\tfoo: %10.5e secs\n",grvy_timer_elapsedseconds("foo"));
  printf("\tbar: %10.5e secs\n",grvy_timer_elapsedseconds("bar"));
  printf("\tboo: %10.5e secs\n",grvy_timer_elapsedseconds("boo"));
 
  printf("\nQuerying individual stats for timer \"bar\" (exclusive values)\n");
  printf("\tbar (   count): %i\n",grvy_timer_stats_count   ("bar"));
  printf("\tbar (    mean): %e\n",grvy_timer_stats_mean    ("bar"));
  printf("\tbar (variance): %e\n",grvy_timer_stats_variance("bar"));
  printf("\tbar (     min): %e\n",grvy_timer_stats_min     ("bar"));
  printf("\tbar (     max): %e\n",grvy_timer_stats_max     ("bar"));
 
  /* The above provides exclusive timing statistics, but you can also
     query inclusive measurements as well */
 
  printf("\nQuerying individual timers (inclusive values):\n");
 
  printf("\tfoo: %10.5e secs\n",grvy_timer_elapsedseconds_inc("foo"));
  printf("\tbar: %10.5e secs\n",grvy_timer_elapsedseconds_inc("bar"));
  printf("\tboo: %10.5e secs\n",grvy_timer_elapsedseconds_inc("boo"));
 
  printf("\nQuerying individual stats for timer \"foo\" (inclusive values)\n");
  printf("\tbar (    mean): %e\n",grvy_timer_stats_mean_inc    ("foo"));
  printf("\tbar (variance): %e\n",grvy_timer_stats_variance_inc("foo"));
  printf("\tbar (     min): %e\n",grvy_timer_stats_min_inc     ("foo"));
  printf("\tbar (     max): %e\n",grvy_timer_stats_max_inc     ("foo"));
 
  /* save measured timing to historical performance DB (required
     optional HDF library linkage) */
 
  const int num_procs = 1;
 
  grvy_timer_save_hist("C-Example1","My clever comment",num_procs,"hist.h5");
 
  return 0;
}
 
 
void foo()
{
  /* Mark the beginning of new timer */
 
  grvy_timer_begin("foo");
 
  usleep(Foo_Sleep);
  bar();
 
  /* Mark the end of the timer */
 
  grvy_timer_end("foo");
 
  return;
    
}
 
void bar()
{
  /* Mark the beginning of new timer (use macro for function name) */
 
  grvy_timer_begin(__func__);
 
  usleep(Bar_Sleep);
  boo();
 
  /* Mark the end of the timer */
 
  grvy_timer_end(__func__);
 
  return;
    
}
 
 
void boo()
{
  /* Mark the beginning of new timer */
 
  grvy_timer_begin(__func__);
 
  usleep(Boo_Sleep);
 
  /* Mark the end of the timer */
 
  grvy_timer_end(__func__);
 
  return;
    
}