// Test malloc and free in order of allocation and reverse
// writing to all allocated locations with all 1s
// requesting random multiples of 8 bytes up to 2**22

#ifndef DEMO_TEST
#include <malloc.h>
extern int rand(void);
#else
#include <stdlib.h>
#endif

#include <stdio.h>
#include <string.h>
#include <pthread.h>

int allones = ~0; // allones for int

int *testmalloc(int size) {
  int *data = (int *) malloc(size);
  if (data != NULL) {
    // void *memset(void *s, int c, size_t n);
    memset((void *) data, allones, size);
  }
  return data;
}

void *test_deadlock() {
   int i;

  for (i = 0; i < 100001; i++) {
    int *data = (int *) testmalloc(8 << (rand() % 20));
    int *data1 = (int *) testmalloc(8 << (rand() % 20));
    int *data2 = (int *) testmalloc(8 << (rand() % 20));
    int *data3 = (int *) testmalloc(8 << (rand() % 20));
    int *data4 = (int *) testmalloc(8 << (rand() % 20));
    int *data5 = (int *) testmalloc(8 << (rand() % 20));
    int *data6 = (int *) testmalloc(8 << (rand() % 20));
    int *data7 = (int *) testmalloc(8 << (rand() % 20));

    free(data);
    free(data1);
    free(data2);
    free(data3);
    free(data4);
    free(data5);
    free(data6);
    free(data7);

    // if ((i%100)==0) fprintf(stderr, "%d...", i);
  }
  fprintf(stderr, "malloc random size, free first to last malloc'd %d times.\n",
          i);

  for (i = 0; i < 100001; i++) {
    int *data = (int *) testmalloc(8 << (rand() % 20));
    int *data1 = (int *) testmalloc(8 << (rand() % 20));
    int *data2 = (int *) testmalloc(8 << (rand() % 20));
    int *data3 = (int *) testmalloc(8 << (rand() % 20));
    int *data4 = (int *) testmalloc(8 << (rand() % 20));
    int *data5 = (int *) testmalloc(8 << (rand() % 20));
    int *data6 = (int *) testmalloc(8 << (rand() % 20));
    int *data7 = (int *) testmalloc(8 << (rand() % 20));

    free(data7);
    free(data6);
    free(data5);
    free(data4);
    free(data3);
    free(data2);
    free(data1);
    free(data);

    // if ((i%100)==0) fprintf(stderr, "%d...", i);
  }
  fprintf(stderr, "malloc random size, free last to first malloc'd %d times.\n",
          i);
}

int main() {
  fprintf(stderr, 
      "=======================================================================\n"
      "Allocator stress test with random sizes from the set {1, 8, 8^2, ..., \n"
      " 8^19}. This stress test might get aborted by the OS if your allocator\n"
      "doesn't manage memory properly, because the VM will simply run out of\n"
      "memory.\n"
      "=======================================================================\n");
  int NUM_THREADS = 1;
  pthread_t threads[NUM_THREADS];
  for (int i = 0; i < NUM_THREADS; i++) {
	  pthread_create(&threads[i], NULL, test_deadlock, NULL);
  }
  for (int i = 0; i < NUM_THREADS; i++) {
	  pthread_join(threads[i], NULL);
  }
  return 0;
}