compile using: gcc -ansi megamalloc.c -o megamalloc

megamalloc.c

#include <stdlib.h>
#include <stdio.h>
#include <time.h>

int main(void) {
  int     i,size;
  int     cumulative_mem=0;
  int     iter=0;
  int    *base;
  clock_t start,end;

  size=1000000;   /* 1 MB in byte */

  srand(time(NULL)); /* random seeding, doesn't have to be very random */
  
  
  while (1) {
    start = clock();
    base = (int *)calloc(size, sizeof(int));
    end = clock();
    
    if(base != NULL) {
      printf("Array of size %d created OK at address %p\n",size,base);
      printf("Allocation took %d milliseconds\n", (int)((end-start)*1E3/CLOCKS_PER_SEC));
      cumulative_mem++;
      printf("Total memory allocated: %d MB\n", cumulative_mem*sizeof(int));
    } else {
      printf("Not enough memory\n");
      printf("Total memory allocated: %d MB\n", cumulative_mem*sizeof(int));
      exit(1);
    }
    
    start = clock();
    int r = rand();
    for(i=0;i<size;i++) { base[i] = r; }
    end = clock();
    printf("Filling the array took %d milliseconds\n", (int)((end-start)*1E3/CLOCKS_PER_SEC));
    for(i=0;i<size;i++) {
      if (base[i]!=r) { 
        printf("Expected %d and found %d at %p", r, base[i], base[i]);
        exit(1);
      }
    }
    if (iter%4==0) { /* we are intentionally leaking some */
      free(base);
      cumulative_mem--;
      printf("Freeing array of size %d at addr %p", size, base);
    }
    end = clock();
    printf("Array verified OK, took %d milliseconds\n", (int)((end-start)*1E3/CLOCKS_PER_SEC));
    iter++;
  }
}