lol_alloc

A laughably simple wasm global_allocator.

Like wee_alloc, but smaller since I used skinnier letters in the name.

lol_alloc is a experimental wasm global_allocator.

I'm writing lol_alloc to learn about allocators (I havent written one before) and because wee_alloc seems unmaintained and has a leak. After looking at wee_alloc's implementation (which I faield to understand or fix), I wanted to find out how hard it really is to make a wasm global_allocator, and it seems like providing one could be useful to the rust wasm community.

Plan

I'd like to offer a few minimal allocator implementations targeted specifically as WebAssembly optimized for code size for various levels of requirements.

Status

Not production ready.

Current a few allocators are provided with minimal testing. If you use it, please report any bugs: I expect there are some.

Currently none are concurrency safe.

Sizes of allocators include overhead from example:

• FailAllocator: 195 bytes: errors on allocations. Operations are O(1),
• LeakingPageAllocator: 230 bytes: Allocates pages for each allocation. Operations are O(1).
• LeakingAllocator: 356 bytes: Bump pointer allocator, growing the heap as needed. Operations are O(1).
• FreeListAllocator: 656 bytes: Free list based allocator. Operations are O(size of free list).

Usage

You can replace the global_allocator in wasm32 with FreeListAllocator builds using:

```

[cfg(target_arch = "wasm32")]

use lol_alloc::FreeListAllocator;

[cfg(target_arch = "wasm32")]

[global_allocator]

static ALLOCATOR: FreeListAllocator = FreeListAllocator::new(); ```

Testing

There are some normal rust unit tests (run with cargo run test), which use a test implementation of MemoryGrower.

There are also some wasm-pack tests (run with wasm-pack test --node lol_alloc)

Size testing:

wasm-pack build --release example && ls -l example/pkg/lol_alloc_example_bg.wasm