While OP might've phrased it more politely, he's got a point - allocators that aren't designed for multithreaded use are ultimately oversimplified toy projects.

While OP might've phrased it more politely, he's got a point - allocators that aren't designed for multithreaded use are ultimately oversimplified toy projects. It's really not that much of a challenge to knock together a (slab + heap + free list) allocator that will perform really well single-threadedly. However it will be nearly impossible to adapt it to the multithreaded context. It is a considerably more complex task and the end result will end up looking like a rocket ship compared to a simpleton that even the best single-threaded allocator will look like.