Update README

README.md

@@ -1,4 +1,20 @@
 
+# Arena Allocator
+
+Arena allocators are region based allocators that tie many allocations to a
+single region of memory. Benefits are massivly simplified allocation and
+deallocation for complex structures, increased performance due to improved
+cache locality, and reduced memory fragmentation as long as individual items
+don't need to be deallocated. For programs that need to micro-manage individual
+allocations this is not an ideal solution.
+
+Deallocating a region of memory with arenas is extremely fast, because the arena
+length is just set to 0. Allocating memory is also extremely fast.
+This implementation also grows the arena on demand using mmap and mprotect.
+Extending the library with a new type of allocation strategy should be easy.
+
+# Reference
+
 ## `arena_t arena_new()`
 
 Allocate a new arena.
@@ -25,13 +41,11 @@ Detach an arena from an existing memory region.
 Reset an arena.
 
 
-
 ## `void *arena_alloc(arena_t *a, size_t len)`
 Allocate memory from an arena.
 Returns NULL and sets errno on failure.
 
 
-
 ## `void *arena_calloc(arena_t *a, size_t nmemb, size_t size)`
 Allocate and zero memory from an arena.
 Returns NULL and sets errno on failure.