Garbage collection of code-allocated stack frames.

git-svn-id: http://svn.drobilla.net/resp/tuplr@130 ad02d1e2-f140-0410-9f75-f8b11f17cedd

1 files changed, 42 insertions, 17 deletions

diff --git a/gc.cpp b/gc.cpp
index a321d35..84ebab1 100644
--- a/gc.cpp
+++ b/gc.cpp
@@ -15,6 +15,7 @@
  * along with Tuplr.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <cassert>
 #include <set>
 #include <iostream>
 #include "tuplr.hpp"
@@ -22,48 +23,72 @@
 using namespace std;
 
 void*
-GC::alloc(size_t size)
+GC::alloc(size_t size, GC::Tag tag)
 {
+	size += (4 - (size % 4)); // Align to 32-bits
+	size += sizeof(Object::Header);
 	void* ret = malloc(size);
+	((Object::Header*)ret)->mark = 0;
+	((Object::Header*)ret)->tag  = tag;
+	ret = (char*)ret + sizeof(Object::Header);
 	_heap.push_back((Object*)ret);
 	return ret;
 }
 
 inline void
-mark(CEnv& cenv, const Object* obj)
+mark(const Object* obj)
 {
-	if (!obj || obj->used)
+	if (!obj || obj->marked())
 		return;
 
-	obj->used = true;
-	const ATuple* tup = dynamic_cast<const ATuple*>(obj);
-	if (tup) {
-		FOREACH(ATuple::const_iterator, i, *tup)
-			mark(cenv, *i);
+	obj->mark(true);
+	if (obj->tag() == GC::TAG_AST) {
+		const AST* ast = static_cast<const AST*>(obj);
+		const ATuple* tup = dynamic_cast<const ATuple*>(ast);
+		if (tup) {
+			FOREACH(ATuple::const_iterator, i, *tup)
+				mark(*i);
+		}
 	}
 }
 
 void
-GC::collect(CEnv& cenv, const Roots& roots)
+GC::collect(const Roots& roots)
 {
+	//const size_t oldSize = _heap.size();
+
 	for (Roots::const_iterator i = roots.begin(); i != roots.end(); ++i)
-		mark(cenv, *i);
+		mark(*i);
 
 	for (Heap::iterator i = _heap.begin(); i != _heap.end();) {
+		assert((*i)->tag() == GC::TAG_AST || (*i)->tag() == GC::TAG_FRAME
+				||(*i)->tag() == GC::TAG_TYPE);
 		Heap::iterator next = i;
 		++next;
-		if ((*i)->used) {
-			(*i)->used = false;
+
+		if ((*i)->marked()) {
+			(*i)->mark(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);
+			AST* ast;
+			switch ((GC::Tag)(*i)->tag()) {
+			case GC::TAG_FRAME:
+				free((char*)(*i) - sizeof(Object::Header));
+				_heap.erase(i);
+				break;
+			case GC::TAG_TYPE:
+				// Don't delete types that are keys in the current type substitution
+				break;
+			case GC::TAG_AST:
+				ast = (AST*)*i;
+				assert(!ast->to<AType*>());
+				(ast)->~AST();
+				free((char*)(*i) - sizeof(Object::Header));
 				_heap.erase(i);
+				break;
 			}
 		}
 		i = next;
 	}
+	//std::cerr << "[GC] Collect " << oldSize << " => " << _heap.size() << endl;
 }