Added: arena allocator

src/arena.c

@@ -0,0 +1,40 @@
+internal Arena *
+arena_initialize(u64 size)
+{
+  Arena *result = 0;
+
+  void *backing_buffer = malloc(size);
+
+  if (backing_buffer != NULL)
+  {
+    result = (Arena*) backing_buffer;
+
+    result->buffer = backing_buffer;
+    result->offset = sizeof(Arena); 
+    result->size   = sizeof(Arena) + size;
+  }
+
+  return result;
+}
+
+internal void *
+arena_allocate(Arena *arena, u64 size)
+{
+  void *result = 0;
+
+  if (arena->offset + size <= arena->size)
+  {
+    result = (void*)((u64) arena->buffer + (u64) arena->offset);
+    arena->offset += size;
+
+    memset(result, 0, size);
+  }
+
+  return result;
+}
+
+internal void
+arena_release(Arena *arena)
+{
+  arena->offset = 0;
+}

src/arena.h

@@ -0,0 +1,31 @@
+#ifndef ARENA_H
+#define ARENA_H
+
+typedef struct Arena Arena;
+struct Arena {
+  u64 *buffer;
+  u64 offset;
+  u64 size;
+};
+
+internal Arena * arena_initialize(u64 size);
+
+internal void * arena_allocate(Arena *arena, u64 size);
+internal void   arena_release(Arena *arena);
+
+//= rhjr: arena helpers
+
+#define arena_push_array(arena, type, count) \
+  (type*) arena_allocate((arena), sizeof(type) * (count))
+
+#define arena_push(arena, type) \
+  (type*) arena_allocate((arena), sizeof(type))
+
+//= rhjr: memory helpers
+
+#define memory_zero(s,z)       memset((s), 0, (z))
+#define memory_zero_struct(s)  memory_zero((s), sizeof(*(s)))
+
+#define memory_copy(dst, src, length) memmove((dst), (src), (length))
+
+#endif // ARENA_H