Generic arena allocator

Also replaces the temp allocator behind the scenes

1 files changed, 27 insertions, 1 deletions

diff --git a/teensy/teensy_mem.h b/teensy/teensy_mem.h
index 133869f..b4cdc62 100644
--- a/teensy/teensy_mem.h
+++ b/teensy/teensy_mem.h
@@ -1,11 +1,37 @@
 #ifndef TEENSY_MEM_H_
 #define TEENSY_MEM_H_
 
+#include <stdint.h>
 #include <stdlib.h>
 
 #define ty_new(T) (ty_alloc(sizeof(T)))
 
-void ty_free_temp_allocs(void);
+// A specific section of memory allocated for an arena.
+typedef struct Arena_Hunk Arena_Hunk;
+struct Arena_Hunk {
+    Arena_Hunk *next;
+    uint8_t *start;
+    uint8_t *end;
+    uint8_t *head;
+};
+
+// Memory arena. It allows the user of this API to allocate lots of memory and
+// free it all at once. Arenas do not support reallocation.
+typedef struct {
+    Arena_Hunk *hunks;
+    size_t hunk_size;
+    size_t alloced_size;
+} Arena;
+
+// Makes an allocation with the speicified arena.
+void *ty_arena_alloc(Arena *arena, size_t size);
+// Frees all allocations made with this arena.
+void ty_arena_clear(Arena *arena);
+// Frees the arena itself. Do NOT call to free allocations made with the arena.
+// Use `ty_arena_clear()` for that.
+void ty_arena_free(Arena *arena);
+
+void ty_clear_temp_allocs(void);
 // Temp allocation. Freed at the end of every frame. Do NOT realloc.
 void *ty_talloc(size_t size);