my big personal nit is poor async support; e.g. async disk IO is recent in Linux, and AFAIK all the Unices implement POSIX aio as a threadpool anyway. not being

my big personal nit is poor async support; e.g. async disk IO is recent in Linux, and AFAIK all the Unices implement POSIX aio as a threadpool anyway. not being able to wait on "either this mutex/semaphore has been signaled, or this IO operation has completed" is also occasionally very annoying...