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.
Allocate a new arena. The underlying memory is allocated with mmap.
Delete memory mapped for arena. Should only be used with arenas from arena_new().
Attach an arena to an existing memory region. The arena will not expand the region if space is exceeded.
Detach an arena from an existing memory region.
Reset an arena.
Allocate memory from an arena. Returns NULL and sets errno on failure.
Allocate and zero memory from an arena. Returns NULL and sets errno on failure.