Re: light weight user level semaphores

[Alan Cox]

> All of this FD allocation stuff is truly distrurbing.
> This appears to be the one place where Win32 got it (almost) right---
> quite about every kernel object looks to userland just like an opaque
> handle, and the same operations apply to all of them.

Unix got this right, then AT&T broke it in System III. One very good reason
for pipe based semaphore stuff is precisely that it works in poll/select/SIGIO

Alan