Collected miscellaneous code

main.c

@@ -11,7 +11,7 @@
 void *get_new_region(uintptr_t size) {
   void *m = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
   if (m == MAP_FAILED) {
-    return 0;
+    return NULL;
   }
   return m;
 }
@@ -54,7 +54,7 @@ void delete_record(struct AllocationRecord *dummy, struct AllocationRecord *dele
 
 struct AllocationRecord *get_record(struct AllocationRecord *dummy, int which) {
   struct AllocationRecord *head = dummy->next;
-  while (--which) {
+  while (which--) {
     head = head->next;
   }
   return head;
@@ -77,6 +77,7 @@ void new_region(struct AllocationRecord *dummy, struct Arena *arena) {
     return;
   }
   for (int ii = 0; ii < size; ii++) {
+    printf("writing %p\n", ((void*) region) + ii);
     ((char*) region)[ii] = (char) rand();
   }
   insert_record(dummy, region, size);
@@ -106,11 +107,13 @@ int act(struct AllocationRecord *dummy, struct Arena *arena) {
       printf("validation failed at id %i\n", head->id);
       die = 1;
     }
+    head = head->next;
   }
   return die;
 }
 
 int main() {
+  srand(1);
   struct Arena arena = {
     NULL,
     NULL,

tree_alloc.c

@@ -302,8 +302,8 @@ void insert_singleton(TreeAlloc **root_ptr, TreeAlloc *to_insert) {
 
 void insert_right(TreeAlloc** root_ptr, TreeAlloc* to_insert, TreeAlloc* after) {
   if (after->right != NULL) {
-    after->right->parent = to_insert;
-    to_insert->right = after->right;
+    after->right = to_insert;
+    to_insert->parent = after;
   }
   after->right = to_insert;
   to_insert->parent = after;
@@ -312,8 +312,8 @@ void insert_right(TreeAlloc** root_ptr, TreeAlloc* to_insert, TreeAlloc* after)
 
 void insert_left(TreeAlloc** root_ptr, TreeAlloc* to_insert, TreeAlloc* before) {
   if (before->left != NULL) {
-    before->left->parent = to_insert;
-    to_insert->left = before->left;
+    before->left = to_insert;
+    to_insert->parent = before;
   }
   before->left = to_insert;
   to_insert->parent = before;
@@ -344,6 +344,14 @@ int add_new_region(Arena *arena, uintptr_t size, uintptr_t padding, uintptr_t al
         head = head->right;
       }
       insert_right((TreeAlloc**) arena->root_freespace, (TreeAlloc*) newreg, (TreeAlloc*) newreg);
+#ifdef DEBUG
+      printf("= POST-REGION-CREATION =\n");
+      printf("==== FREESPACE TREE ====\n");
+      debug_print_tree(0, arena->root_freespace);
+      printf("==== TREEALLOC TREE ====\n");
+      debug_print_tree(0, arena->root_treealloc);
+      printf("===== END OF TREES =====\n");
+#endif
     }
     return 1;
 }
@@ -355,7 +363,7 @@ void unalloc(Arena *arena, void *addr) {
   debug_print_tree(0, arena->root_freespace);
   printf("=== TREEALLOC TREE ===\n");
   debug_print_tree(0, arena->root_treealloc);
-  printf("=== END OF TREES ====\n");
+  printf("==== END OF TREES ====\n");
 #endif
   if (arena->root_treealloc == NULL) {
     arena->error("attempt to unallocate when there are no allocations!");
@@ -414,7 +422,7 @@ void *alloc(Arena *arena, uintptr_t size, uintptr_t align) {
   debug_print_tree(0, arena->root_freespace);
   printf("=== TREEALLOC TREE ===\n");
   debug_print_tree(0, arena->root_treealloc);
-  printf("=== END OF TREES ====\n");
+  printf("==== END OF TREES ====\n");
 #endif
   if (arena->root_freespace == NULL) {
     // Handle being out of freespace.
@@ -441,7 +449,6 @@ void *alloc(Arena *arena, uintptr_t size, uintptr_t align) {
     region->left = NULL;
     region->type = RT_TREE_NODE;
 #ifdef DEBUG
-    printf("sizeof(TreeAlloc): %lu\n", (uintptr_t) sizeof(TreeAlloc));
     printf("start: %p, end: %p, adjusted end: %p\n", region, ((void*) region) + size, true_end);
     printf("size: %lu -> %lu\n", size, new_size);
 #endif
@@ -479,7 +486,10 @@ void *alloc(Arena *arena, uintptr_t size, uintptr_t align) {
     } else {
       region->before = before_alloc;
     }
-    return align_after(region + sizeof(TreeAlloc), actual_align);
+#ifdef DEBUG
+    printf("region is still at %p\n", region);
+#endif
+    return align_after((void*) region + sizeof(TreeAlloc), actual_align);
   }
 }