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

#define minObjects 100

typedef struct _TestObject TestObject;

struct _TestObject {
	int item;
	TestObject *parent;
	volatile int ref;
};

TestObject *test_object_new(int item) {
	TestObject *obj = calloc(1, sizeof(TestObject));
	obj->item = item;
	obj->ref = 1;
	return obj;
}

int test_object_get_item(TestObject *o) {
	if (o != NULL)
		return o->item;
}

TestObject *test_object_ref(TestObject *o) {
	if (o != NULL) {
		o->ref++;
	}
	return o;
}

TestObject *test_object_unref(TestObject **oo) {
	if (oo == NULL || *oo == NULL)
		return NULL;

	TestObject *o = *oo;

	if (o != NULL && o->ref-- == 1) {
		test_object_unref(&(o->parent));
		free(o);
		o = NULL;
	}
	return o;
}

void test_object_set_parent(TestObject *o, TestObject *parent) {
	test_object_unref(&(o->parent));
	o->parent = test_object_ref(parent);
}

int main (int argc, char ** argv) {
	int o;
	int n = 5000000;

	if (argc > 1) {
		n = atoi(argv[1]);
	}

	int objects = minObjects > n ? minObjects : n;
	TestObject **latest = calloc(minObjects+1, sizeof(TestObject*));
	TestObject *firstObj = test_object_new(0);
	latest[0] = test_object_ref(firstObj);

	for (o = 0; o < objects; o++) {
		TestObject *obj = test_object_new(o+1);

		if (o % (objects/10) == 0) {
			printf("Allocated object: %d check %d\n",(o+1),test_object_get_item(obj));
		}

		TestObject *tmp = latest[o%minObjects+1];
		test_object_unref(&tmp);
		latest[o%minObjects+1] = test_object_ref(obj);

		int idx = ((o/2) % minObjects) + 1;
		TestObject *my = latest[idx];
		while (my == NULL || my == obj) {
			idx /= 2;
			my = latest[idx];
		}
		test_object_set_parent(obj, my);
		test_object_unref(&obj);
	}

	for (o = 0; o < minObjects+1; o++) {
		test_object_unref(&(latest[o]));
	}

	test_object_unref(&firstObj);
}