Dren fucked around with this message at 16:06 on Apr 24, 2014

Sauer fucked around with this message at 22:50 on Apr 24, 2014

Paul MaudDib fucked around with this message at 00:41 on Apr 25, 2014

taqueso fucked around with this message at 01:40 on Apr 25, 2014

struct arena {
	size_t used;
	size_t capacity;
};

struct arena* new_arena(void *start, size_t capacity) {
	if (start == NULL) return NULL;
	if (capacity < sizeof(struct arena)) return NULL;

	struct arena *a = (struct arena*)start;
	a->used = sizeof(struct arena);
	a->capacity = capacity;
	return a;
}

void* arena_malloc(struct arena *a, size_t size) {
	if (a == NULL) return NULL;
	if (a->used + size > a->capacity) return NULL;

	void* tmp = a->used + (void*)a;
	a->used += size;
	return tmp;
}

void arena_free(struct arena* a, void* p) {
	// do nothing
}

union foo {
	int a;
	float b;
	char c;
};

int main() {
	// say I have a block of memory all my own
	char block[0x10000];

	// I can make an allocator that will manage it for me
	struct arena *a = new_arena(block, sizeof(block));
	if (a == NULL) return EXIT_FAILURE;

	// let's get a union foo sized slice from it
	union foo *u = arena_malloc(a, sizeof(union foo));
	if (u == NULL) return EXIT_FAILURE;
	u->a = 3;
	u->c = '3';
	u->b = 3.1415;
	arena_free(a, u);

	// cleanup "block" if needed
}

The Laplace Demon fucked around with this message at 12:37 on Apr 26, 2014

The Laplace Demon fucked around with this message at 13:05 on Apr 26, 2014