/* Test that overwrite error detection works reasonably. */

#ifndef GC_DEBUG
#  define GC_DEBUG
#endif

#include "gc.h"

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

#define COUNT 7000
#define SIZE 40

#define CHECK_OUT_OF_MEMORY(p)            \
  do {                                    \
    if (NULL == (p)) {                    \
      fprintf(stderr, "Out of memory\n"); \
      exit(69);                           \
    }                                     \
  } while (0)

char *A[COUNT];

char *volatile q;

int
main(void)
{
  int i;
  char *p;

  GC_INIT();
  for (i = 0; i < COUNT; ++i) {
    A[i] = p = (char *)GC_MALLOC(SIZE);
    CHECK_OUT_OF_MEMORY(p);
    if (i % 3000 == 0) {
      q = NULL;
      GC_gcollect();
    } else if (i % 5678 == 0) {
      /*
       * Write a byte past the end of the allocated object but not beyond
       * the last word of the object's memory.  A `volatile` intermediate
       * pointer variable is used to avoid a compiler complain of
       * out-of-bounds access.
       */
      q = &p[(SIZE + i / 2000) /* 42 */];
      *q = 42;
    }
  }
  printf("SUCCEEDED\n");
  return 0;
}