From 56311a928d78b1dae0c66b2dd4f5479678065cbb Mon Sep 17 00:00:00 2001
From: Andrew Scott <git@andyscott.me>
Date: Tue, 20 Aug 2024 10:55:53 -0400
Subject: [PATCH] VM: added reference tracing

---
 vm.c | 9 +++++++++
 vm.h | 2 ++
 2 files changed, 11 insertions(+)

diff --git a/vm.c b/vm.c
index b955cd2..68d37b7 100644
--- a/vm.c
+++ b/vm.c
@@ -2,10 +2,14 @@
 #include <stdlib.h>
 
 #include "vm.h"
+#include "gc.h"
 
 struct virtualMachine *initVM() {
   struct virtualMachine *vm = malloc(sizeof(struct virtualMachine));
   vm->stackSize = 0;
+  vm->refCount = 0;
+  vm->refMax = STACK_MAX / 2;
+  vm->head = NULL;
   return vm;
 }
 
@@ -29,9 +33,14 @@ struct garbageObject *pop(struct virtualMachine *vm) {
 
 struct garbageObject *initGarbage(struct virtualMachine *vm,
                                   enum garbageData type) {
+  if (vm->refCount == vm->refMax) collect(vm);
+
   struct garbageObject *obj = malloc(sizeof(struct garbageObject));
   obj->type = type;
   obj->mark = 0;
+  obj->next = vm->head;
+  vm->head = obj;
+  vm->refCount++;
   return obj;
 }
 
diff --git a/vm.h b/vm.h
index f37f724..90803e4 100644
--- a/vm.h
+++ b/vm.h
@@ -28,6 +28,8 @@ struct garbageObject {
 // Virtual machine hold the stack to trace references
 struct virtualMachine {
   int stackSize;
+  unsigned refCount;
+  unsigned refMax;
   struct garbageObject *head;
   struct garbageObject *stack[STACK_MAX];
 };