Re: Async IO

Greg Alexander (galexand@sietch.bloomington.in.us)
Sun, 26 Jan 1997 16:58:50 -0500 (EST)


On 26 Jan 1997, Andi Kleen wrote:

> > I had the same idea, and I'd just started work on putting together such a
> > library when I got your email :) What I'm planning to do is build a
> > library that sits on top of LinuxThreads and glibc, and implements the
> > asynch i/o stuff as found in POSIX 1003.1b. (This is the aio_read() etc.
> > stuff in Solaris.)
>
> One problem currently is that Linux doesn't have enough signals.
> In practive you can only use SIGUSR1 and SIGUSR2 for your async aio
> stuff and that's usually not enough. Linuxthreads already needs SIGUSR1
> so you can't use it. You'll probably have to wait for full POSIX 1003.1b
> signal support in Linux.

You only need to use one signal, then the signal handler will look at some
shared memory to see what the signal was for. And there's no really good
reason that i know of to not use SIGHUP, SIGCHLD, SIGIO, SIGPWR, etc.

Greg Alexander
http://www.cia-g.com/~sietch/