/* Tuplr: A programming language
 * Copyright (C) 2008-2009 David Robillard <dave@drobilla.net>
 *
 * Tuplr is free software: you can redistribute it and/or modify it under
 * the terms of the GNU Affero General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or (at your
 * option) any later version.
 *
 * Tuplr is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General
 * Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with Tuplr.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <set>
#include <iostream>
#include "tuplr.hpp"

using namespace std;

void*
GC::alloc(size_t size)
{
	void* ret = malloc(size);
	_heap.push_back((Object*)ret);
	return ret;
}

inline void
mark(CEnv& cenv, const Object* obj)
{
	if (!obj || obj->used)
		return;

	obj->used = true;
	const ATuple* tup = dynamic_cast<const ATuple*>(obj);
	if (tup) {
		FOREACH(ATuple::const_iterator, i, *tup) {
			mark(cenv, *i);
			mark(cenv, cenv.type(*i));
		}
	}
}

void
GC::collect(CEnv& cenv, const Roots& roots)
{
	for (Roots::const_iterator i = roots.begin(); i != roots.end(); ++i)
		mark(cenv, *i);

	for (Heap::iterator i = _heap.begin(); i != _heap.end();) {
		Heap::iterator next = i;
		++next;
		if ((*i)->used) {
			(*i)->used = false;
		} else {
			AType* t = dynamic_cast<AType*>(*i);
			// Don't delete types that are keys in the current type substitution
			if (!t || cenv.tsubst.find(t) == cenv.tsubst.end()) {
				(*i)->~Object();
				free(*i);
				_heap.erase(i);
			}
		}
		i = next;
	}
}