xref: /petsc/src/benchmarks/PetscGetCPUTime.c (revision e1311b9049e89cb3452dcd306fde571f4b440ff2)
1 #ifdef PETSC_RCS_HEADER
2 static char vcid[] = "$Id: PetscGetCPUTime.c,v 1.2 1997/10/19 03:30:47 bsmith Exp balay $";
3 #endif
4 
5 #include "petsc.h"
6 
7 int main( int argc, char **argv)
8 {
9   PLogDouble x, y;
10   long int   i,j,A[100000],ierr;
11 
12   PetscInitialize(&argc, &argv,0,0);
13  /* To take care of paging effects */
14   ierr = PetscGetCPUTime(&y); CHKERRA(ierr);
15 
16   for ( i=0; i<2; i++ ) {
17     ierr = PetscGetCPUTime(&x); CHKERRA(ierr);
18 
19     /*
20        Do some work for at least 1 ms. Most CPU timers
21        cannot measure anything less than that
22      */
23 
24     for (j=0; j<20000*(i+1); j++) {
25       A[j]=i+j;
26     }
27     ierr = PetscGetCPUTime(&y); CHKERRA(ierr);
28     fprintf(stderr,"%-15s : %e sec\n","PetscGetCPUTime", (y-x)/10.0);
29   }
30 
31   PetscFinalize();
32   PetscFunctionReturn(0);
33 }
34