Fixed some bugs

tree_alloc.c

@@ -12,9 +12,9 @@ void debug_print_tree(int indent, void *p) {
   if (node != NULL) {
     debug_print_tree(indent + 1, node->left);
     for (int ii = 0; ii < indent; ii++) { printf("  "); }
-    if (node->color == COLOR_RED) { printf("\e[31"); }
+    if (node->color == COLOR_RED) { printf("\e[31m"); }
     printf("%p %lu\n", node, node->size);
-    if (node->color == COLOR_RED) { printf("\e[37"); }
+    if (node->color == COLOR_RED) { printf("\e[37m"); }
     debug_print_tree(indent + 1, node->right);
   }
 }
@@ -173,7 +173,6 @@ void repair_tree_after_insert(TreeAlloc **root_ptr, TreeAlloc *ta) {
 		ta->color = COLOR_BLACK;
 		return;
 	}
-	
 	TreeAlloc *grandparent = parent->parent;
 	TreeAlloc *uncle = get_sibling(parent);
 
@@ -187,12 +186,13 @@ void repair_tree_after_insert(TreeAlloc **root_ptr, TreeAlloc *ta) {
 				if (ta == parent->left && parent == grandparent->left) {
 						rotate_left(root_ptr, parent);
 						ta = ta->left;
+            parent = parent->left;
 				} else {
 						rotate_right(root_ptr, parent);
 						ta = ta->right;	
+            parent = parent->right;
 				}
 
-				parent = ta->parent;
 				grandparent = parent->parent;
 				if (ta == parent->left) {
 						rotate_right(root_ptr, grandparent);
@@ -222,7 +222,7 @@ void repair_after_remove(TreeAlloc **root_ptr, TreeAlloc *node) {
 		node->color = COLOR_BLACK;
 	} else {
 		TreeAlloc *sibling = get_sibling(node);
-		if (sibling->color == COLOR_RED) {
+		if (sibling != NULL && sibling->color == COLOR_RED) {
 			if (node->parent->left == node)
 				rotate_left(root_ptr, node->parent);
 			else
@@ -261,6 +261,12 @@ void repair_after_remove(TreeAlloc **root_ptr, TreeAlloc *node) {
 
 void remove_node(TreeAlloc **root_ptr, TreeAlloc *node) {
 	char do_repair = 0;
+#ifdef DEBUG
+      printf("====== PRE-REMOVE ======\n");
+      printf("===== CURRENT TREE =====\n");
+      debug_print_tree(0, *root_ptr);
+      printf("===== END OF TREES =====\n");
+#endif
 	TreeAlloc *replace;
 	TreeAlloc *parent = node->parent;
 	if (!node->left) {
@@ -287,7 +293,13 @@ void remove_node(TreeAlloc **root_ptr, TreeAlloc *node) {
 		node->left->parent = tmp;
 	}
 
-	if (do_repair && replace) {
+	if (do_repair && replace && replace->parent != NULL) {
+#ifdef DEBUG
+      printf("=== PRE-REMOVE-FIXUP ===\n");
+      printf("===== CURRENT TREE =====\n");
+      debug_print_tree(0, *root_ptr);
+      printf("===== END OF TREES =====\n");
+#endif
 		repair_after_remove(root_ptr, replace);
 	}
 }
@@ -456,7 +468,15 @@ void *alloc(Arena *arena, uintptr_t size, uintptr_t align) {
       insert_singleton((TreeAlloc**) &arena->root_treealloc, region);
     } else {
       TreeAlloc *insert_point = search_by_address((TreeAlloc*) arena->root_treealloc, region);
-      insert_right(&arena->root_treealloc, region, insert_point);
+      if (insert_point == NULL) {
+        TreeAlloc *head = arena->root_treealloc;
+        while (head->left != NULL) {
+          head = head->left;
+        }
+        insert_left(&arena->root_treealloc, region, head);
+      } else {
+        insert_right(&arena->root_treealloc, region, insert_point);
+      }
     }
     if (new_free_size >= sizeof(FreeSpace)) {
       // If there's enough free space after the allocation, use it!
@@ -479,6 +499,10 @@ void *alloc(Arena *arena, uintptr_t size, uintptr_t align) {
       // region.
       region->after = succ(region);
     }
+    // I seem to have forgotten about the fact that memory may not be contiguous
+    if (region->after != NULL && region->after != (void*) region + region->size) {
+      region->after = NULL;
+    }
     // Also make sure the `before` pointer is correct.
     TreeAlloc *before_alloc = pred(region);
     if (before_alloc == NULL || ((void*) before_alloc) + before_alloc->size < (void*) region) {
@@ -486,6 +510,10 @@ void *alloc(Arena *arena, uintptr_t size, uintptr_t align) {
     } else {
       region->before = before_alloc;
     }
+    // I seem to have forgotten about the fact that memory may not be contiguous
+    if (region->before != NULL && region->before != (void*) region->before + region->before->size) {
+      region->before = NULL;
+    }
 #ifdef DEBUG
     printf("region is still at %p\n", region);
 #endif