#include <stdlib.h>
#include <stdio.h>
#include <sys/mman.h>
#include <pthread.h>

#define NR_THREADS	1
#define ITERS	1000000
#define HEAPSIZE	(4*1024)

static void *old_thread(void *heap)
{
	int i;

	for (i = 0; i < ITERS; i++) {
		char *mem = heap;
		if (mprotect(heap, HEAPSIZE, PROT_READ|PROT_WRITE) == -1)
			perror("mprotect"), exit(1);
		*mem = i;
		if (mmap(heap, HEAPSIZE, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, -1, 0) == MAP_FAILED)
			perror("mmap"), exit(1);
	}

	return NULL;
}

static void old_test(void)
{
	void *heap;
	pthread_t pt[NR_THREADS];
	int i;

	heap = mmap(NULL, NR_THREADS*HEAPSIZE, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
	if (heap == MAP_FAILED)
		perror("mmap"), exit(1);

	for (i = 0; i < NR_THREADS; i++) {
		if (pthread_create(&pt[i], NULL, old_thread, heap + i*HEAPSIZE) == -1)
			perror("pthread_create"), exit(1);
	}
	for (i = 0; i < NR_THREADS; i++) {
		if (pthread_join(pt[i], NULL) == -1)
			perror("pthread_join"), exit(1);
	}

	if (munmap(heap, NR_THREADS*HEAPSIZE) == -1)
		perror("munmap"), exit(1);
}

static void *new_thread(void *heap)
{
	int i;

	for (i = 0; i < ITERS; i++) {
		char *mem = heap;
		*mem = i;
		if (madvise(heap, HEAPSIZE, MADV_DONTNEED) == -1)
			perror("madvise"), exit(1);
	}

	return NULL;
}

static void new_test(void)
{
	void *heap;
	pthread_t pt[NR_THREADS];
	int i;

	heap = mmap(NULL, HEAPSIZE, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
	if (heap == MAP_FAILED)
		perror("mmap"), exit(1);

	for (i = 0; i < NR_THREADS; i++) {
		if (pthread_create(&pt[i], NULL, new_thread, heap + i*HEAPSIZE) == -1)
			perror("pthread_create"), exit(1);
	}
	for (i = 0; i < NR_THREADS; i++) {
		if (pthread_join(pt[i], NULL) == -1)
			perror("pthread_join"), exit(1);
	}

	if (munmap(heap, HEAPSIZE) == -1)
		perror("munmap"), exit(1);
}

int main(void)
{
	old_test();

	exit(0);
}