Added a finalize method to all Objects and modified the garbage

collector to deal with objects that might gain references during
finalization.

include/QF/object.h

@@ -74,12 +74,14 @@ struct List_s;
 typedef void (*ReplyHandler_t) (struct Object_s *retValue);
 
 typedef struct Object_s {
+	unsigned marked :1;
+	unsigned finalized :1;
 	struct Class_s *cl;
 	int refs;
-	qboolean marked;
 	struct Object_s *next;
 	struct String_s * methodDecl(Object, toString);
 	ObjRefs_t * methodDecl(Object, allRefs);
+	qboolean methodDecl(Object, finalize);
 	void *data;
 
 } Object;

include/garbage.h

@@ -33,8 +33,8 @@
 #define __garbage_h
 
 void Garbage_Do_Mark (Object *root);
-void Garbage_Do_Sweep (Object **allobjs);
+Object * Garbage_Do_Sweep (Object **allobjs);
 unsigned int Garbage_Pending (void);
-void Garbage_Dispose (unsigned int amount);
+void Garbage_Dispose (Object **allobjs, unsigned int amount);
 
 #endif

libs/object/garbage.c

@@ -61,24 +61,32 @@ Garbage_Do_Mark (Object *root)
 	}
 }
 
-void
+Object *
 Garbage_Do_Sweep (Object **allobjs)
 {
 	Object **prevNext;
 	Object *obj;
 
-	for (prevNext = allobjs, obj = *allobjs; obj; obj = *prevNext) {
+	for (prevNext = allobjs, obj = *allobjs;; obj = *prevNext) {
 		if (obj->marked) {
 			obj->marked = false;
 			prevNext = &obj->next;
 		} else if (!obj->refs) {
-			*prevNext = obj->next;
-			obj->next = junk;
-			junk = obj;
-			junked++;
-			Sys_DPrintf ("GC: %s@%p is ready for disposal...\n", obj->cl->name, obj);
+			if (!obj->finalized && methodCall(obj, finalize)) {
+				obj->finalized = true;
+				Garbage_Do_Mark (obj);
+				prevNext = &obj->next;
+			} else {
+				*prevNext = obj->next;
+				obj->next = junk;
+				junk = obj;
+				junked++;
+				Sys_DPrintf ("GC: %s@%p is ready for disposal...\n", obj->cl->name, obj);
+			}
 		} else
 			*prevNext = obj->next;
+		if (!*prevNext)
+			return obj;
 	}
 }
 
@@ -89,14 +97,20 @@ Garbage_Pending (void)
 }
 
 void
-Garbage_Dispose (unsigned int amount)
+Garbage_Dispose (Object **allobjs, unsigned int amount)
 {
 	Object *next;
 
 	for (; junk && amount; junk = next, amount--) {
 		next = junk->next;
-		Sys_DPrintf ("GC: Disposing of %s@%p...\n", junk->cl->name, junk);
-		Object_Delete (junk);
-		junked--;
+		if (junk->marked) {
+			junk->marked = false;
+			junk->next = *allobjs;
+			*allobjs = junk;
+		} else {
+			Sys_DPrintf ("GC: Disposing of %s@%p...\n", junk->cl->name, junk);
+			Object_Delete (junk);
+			junked--;
+		}
 	}
 }

libs/object/object.c

@@ -61,6 +61,12 @@ static __attribute__ ((unused)) const char rcsid[] =
 Object *allObjs = NULL;
 ArrayList *rootObj = NULL;
 
+static qboolean
+Object_Finalize_f (Object *self)
+{
+	return false;
+}
+
 static String *
 Object_ToString_f (Object *self) 
 {
@@ -72,6 +78,7 @@ Object_Init_f (Object *self)
 {
 	self->allRefs = NULL;
 	self->toString = Object_ToString_f;
+	self->finalize = Object_Finalize_f;
 	Sys_DPrintf("%s@%p initing...\n", self->cl->name, self);
 }
 
@@ -117,6 +124,7 @@ Object_Create (Class *cl, qboolean floating)
 	} else
 		new->refs = 1;
 	new->marked = false;
+	new->finalized = false;
 	new->next = allObjs;
 	allObjs = new;
 	return new;
@@ -243,13 +251,18 @@ Object_Garbage_Collect (void)
 	frames++;
 
 	if (frames % 2000 == 0) {
+		Object *all, *last;
 		Sys_DPrintf("GC: Marking...\n");
 		Garbage_Do_Mark (OBJECT(rootObj));
 		Sys_DPrintf("GC: Sweeping...\n");
-		Garbage_Do_Sweep (&allObjs);
+		all = allObjs;
+		allObjs = NULL;
+		last = Garbage_Do_Sweep (&all);
+		last->next = allObjs;
+		allObjs = all;
 	}
 	if (frames % 50 == 0 && Garbage_Pending()) {
 		Sys_DPrintf("GC: Disposing...\n");
-		Garbage_Dispose (Garbage_Pending()/2 + 1);
+		Garbage_Dispose (&allObjs, Garbage_Pending()/2 + 1);
 	}
 }