Actual source code: PetscMalloc.c
petsc-3.10.5 2019-03-28
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      2:  #include <petscsys.h>
      3:  #include <petsctime.h>

      5: int main(int argc,char **argv)
      6: {
      7:   PetscLogDouble x,y;
      8:   double         value;
      9:   void           *arr[1000],*dummy;
     10:   int            i,rand1[1000],rand2[1000];
     12:   PetscRandom    r;
     13:   PetscBool      flg;

     15:   PetscInitialize(&argc,&argv,0,0);if (ierr) return ierr;
     16:   PetscRandomCreate(PETSC_COMM_SELF,&r);
     17:   PetscRandomSetFromOptions(r);
     18:   for (i=0; i<1000; i++) {
     19:     PetscRandomGetValue(r,&value);
     20:     rand1[i] = (int)(value* 144327);
     21:     PetscRandomGetValue(r,&value);
     22:     rand2[i] = (int)(value* 144327);
     23:   }

     25:   /* Take care of paging effects */
     26:   PetscMalloc1(100,&dummy);
     27:   PetscFree(dummy);
     28:   PetscTime(&x);

     30:   /* Do all mallocs */
     31:   for (i=0; i< 1000; i++) {
     32:     PetscMalloc1(rand1[i],&arr[i]);
     33:   }

     35:   PetscTime(&x);

     37:   /* Do some frees */
     38:   for (i=0; i< 1000; i+=2) {
     39:     PetscFree(arr[i]);
     40:   }

     42:   /* Do some mallocs */
     43:   for (i=0; i< 1000; i+=2) {
     44:     PetscMalloc1(rand2[i],&arr[i]);
     45:   }
     46:   PetscTime(&y);

     48:   for (i=0; i< 1000; i++) {
     49:     PetscFree(arr[i]);
     50:   }

     52:   fprintf(stdout,"%-15s : %e sec, with options : ","PetscMalloc",(y-x)/500.0);
     53:   PetscOptionsHasName(NULL,"-malloc",&flg);
     54:   if (flg) fprintf(stdout,"-malloc ");
     55:   fprintf(stdout,"\n");

     57:   PetscRandomDestroy(&r);
     58:   PetscFinalize();
     59:   return ierr;
     60: }