select() and serial drivers

[Joel Sherrill]

Antti P Miettinen wrote:
> 
> > If you're starting to write a new application, in many cases it's better
> > to use one thread per socket/tty instead of using select().  A call to
> > select() is quite expensive (and not only on RTEMS, but on vxWorks and
> > Linux, too).
> 
> Hmm.. thats a surprise to me. How does the price of a context switch
> compare?

Depends on the CPU and int versus int+FPU.  Can be quite small.
Run tm26 on your target.  

> What are the alternatives for waiting for multiple IO sources? I've
> grown to like single threaded applications :)

Implementing select() in general. :)  Seriously making sure
termios devices were supported as well would take care of serial
ports. 

No one is saying it isn't worth implementing, just that there
are alternatives that they consider more palatable than implementing
select() personally. :)

And that does not mean that sponsoring the addition of this
functionality
would not be welcomed.

> Antti Miettinen
> Nokia Networks

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