Finish basic implementation of garbage collection.

include/gc.h

@@ -33,6 +33,10 @@ void libab_gc_list_init(libab_gc_list* list);
  * @param data the data to pass to the visitor.
  */
 void libab_gc_visit_children(struct libab_ref_s* ref, libab_visitor_function_ptr visitor, void* data);
+/**
+ * Applies the given visitor function to this reference.
+ */
+void libab_gc_visit(struct libab_ref_s* ref, libab_visitor_function_ptr visitor, void* data);
 /**
  * Adds the given reference to the given garbage collection list,
  * and specifies a function used to reach its children.

include/refcount_internal.h

@@ -0,0 +1,8 @@
+#ifndef LIBABACUS_REFCOUNT_INTERNAL_H
+#define LIBABACUS_REFCOUNT_INTERNAL_H
+
+#include "refcount.h"
+
+void libab_ref_count_changed(libab_ref_count* count);
+
+#endif

src/gc.c

@@ -1,7 +1,9 @@
 #include "gc.h"
 #include "refcount.h"
 #include <stdlib.h>
+#include <stdio.h>
 #include <memory.h>
+#include "refcount_internal.h"
 
 void libab_gc_list_init(libab_gc_list* list) {
     memset(&list->head_sentinel, 0, sizeof(list->head_sentinel));
@@ -17,6 +19,12 @@ void libab_gc_visit_children(libab_ref* ref, libab_visitor_function_ptr func, vo
     if(!ref->null) _gc_count_visit_children(ref->count, func, data);
 }
 
+void libab_gc_visit(struct libab_ref_s* ref, libab_visitor_function_ptr visitor, void* data) {
+    if(!ref->null) {
+        visitor(ref->count, data);
+    }
+}
+
 void _libab_gc_list_append(libab_gc_list* list,
                                libab_ref_count* node) {
     libab_ref_count* before;
@@ -36,11 +44,11 @@ void libab_gc_add(libab_ref* ref,
 }
 
 void _gc_decrement(libab_ref_count* count, void* data) {
-    count->gc--;
+    if(count->visit_children) count->gc--;
 }
 void _gc_save(libab_ref_count* count, void* data) {
     libab_gc_list* list = data;
-    if(count->visit_children && count->gc != -1) {
+    if(count->visit_children && count->gc >= 0) {
         count->gc = -1;
         _libab_gc_list_append(list, count);
         _gc_count_visit_children(count, _gc_save, data);
@@ -50,31 +58,45 @@ void _gc_save(libab_ref_count* count, void* data) {
 void libab_gc_run(libab_gc_list* list) {
     libab_gc_list safe;
     libab_ref_count* head;
-    size_t count = 0;
 
     #define ITERATE(CODE) head = list->head_sentinel.next; \
     while(head != &list->tail_sentinel) { \
+        libab_ref_count* node = head; \
         CODE;\
         head = head->next; \
     }
 
     libab_gc_list_init(&safe);
-    ITERATE(head->gc = head->weak);
-    ITERATE(_gc_count_visit_children(head, _gc_decrement, NULL));
-    ITERATE(printf("%d outside references\n", head->gc));
-    ITERATE(_gc_count_visit_children(head, _gc_save, &safe));
-    ITERATE(count++);
+    ITERATE(node->gc = node->weak);
+    ITERATE(_gc_count_visit_children(node, _gc_decrement, NULL));
+    
+    head = list->head_sentinel.next;
+    while(head != &list->tail_sentinel) {
+        if(head->gc > 0) {
+            _gc_save(head, &safe);
+            head = &list->head_sentinel;
+        }
+        head = head->next;
+    }
 
-    printf("Can free %d\n", count);
+    ITERATE(
+        node->weak = -1;
+        node->strong = -1;
+        if(node->free_func) node->free_func(node->data);
+    );
+
+    while ((head = list->head_sentinel.next) != &list->tail_sentinel) {
+        head->prev->next = head->next;
+        head->next->prev = head->prev;
+        free(head);
+    }
 
     if(safe.head_sentinel.next != &safe.tail_sentinel) {
-        printf("Safe isn't empty!\n");
         list->head_sentinel.next = safe.head_sentinel.next;
         list->head_sentinel.next->prev = &list->head_sentinel;
         list->tail_sentinel.prev = safe.tail_sentinel.prev;
         list->tail_sentinel.prev->next = &list->tail_sentinel;
     } else {
-        printf("Safe is empty!\n");
         list->head_sentinel.next = &list->tail_sentinel;
         list->tail_sentinel.prev = &list->head_sentinel;
     }

src/refcount_internal.c

@@ -0,0 +1,16 @@
+#include "refcount_internal.h"
+#include <stdlib.h>
+
+void libab_ref_count_changed(libab_ref_count* count) {
+    if (count->strong == 0) {
+        count->strong--;
+        if (count->free_func) {
+            count->free_func(count->data);
+        }
+    }
+    if (count->weak == 0) {
+        if(count->prev) count->prev->next = count->next;
+        if(count->next) count->next->prev = count->prev;
+        free(count);
+    }
+}

src/util.c

@@ -189,13 +189,14 @@ libab_result libab_instantiate_basetype(libab_basetype* to_instantiate,
 
 void _gc_visit_table_entry(libab_table_entry* entry, libab_visitor_function_ptr visitor, void* data) {
     if (entry->variant == ENTRY_VALUE) {
-        libab_gc_visit_children(&entry->data_u.value, visitor, data);
+        libab_gc_visit(&entry->data_u.value, visitor, data);
     }
 }
 
 void _gc_visit_table_trie(libab_trie_node* parent, libab_visitor_function_ptr visitor, void* data) {
-    ll_node* head = parent->values.head;
+    ll_node* head;
     if(parent == NULL) return;
+    head = parent->values.head;
     _gc_visit_table_trie(parent->child, visitor, data);
     _gc_visit_table_trie(parent->next, visitor, data);
     while(head != NULL) {
@@ -206,7 +207,8 @@ void _gc_visit_table_trie(libab_trie_node* parent, libab_visitor_function_ptr vi
 
 void _gc_visit_table_children(void* parent, libab_visitor_function_ptr visitor, void* data) {
     libab_table* table = parent;
-    libab_gc_visit_children(&table->parent, visitor, data);
+    libab_gc_visit(&table->parent, visitor, data);
+    _gc_visit_table_trie(table->trie.head, visitor, data);
 }
 
 libab_result libab_create_table(libab* ab, libab_ref* into, libab_ref* parent) {
@@ -234,7 +236,7 @@ libab_result libab_create_table(libab* ab, libab_ref* into, libab_ref* parent) {
 
 void _gc_visit_value_children(void* val, libab_visitor_function_ptr visitor, void* data) {
     libab_value* value = val;
-    libab_gc_visit_children(&value->data, visitor, data);
+    libab_gc_visit(&value->data, visitor, data);
 }
 
 libab_result libab_create_value_ref(libab* ab, libab_ref* into, 
@@ -290,7 +292,7 @@ libab_result libab_create_value_raw(libab* ab, libab_ref* into,
 
 void _gc_visit_function_children(void* function, libab_visitor_function_ptr visitor, void* data) {
     libab_function* func = function;
-    libab_gc_visit_children(&func->scope, visitor, data);
+    libab_gc_visit(&func->scope, visitor, data);
 }
 
 libab_result libab_create_function_internal(libab* ab, libab_ref* into,