Re: Signals from ethernet card driver

[Matthew Heaney <matthew_heaney@acm.org>]

askeya <askeya@res.raytheon.com> writes:

> I am trying to get a driver to signal my Ada program when a TCP/IP
> message arrives over an ethernet on a Sun running Solaris 2.7.  It would
> be great if the signal would act as a task rendezvous.  I have done this
> on a VAX with VMS using Starlet, but don't have a clue if it can be done
> on a Sun with Solaris.
> 
> First question: can the driver send a signal when a message arrives?

I'm not very driver-literate, but does the client do the I/O using a
file descriptor?  Won't SIGIO (SIGPOLL) work?

> Second question:  In theory, can I receive that signal in my program?

Try declaring an interrupt handler to catch the signal SIGIO (SIGPOLL).  

> Third question (if you feel ambitious): In general, how?

In Ada95, you declare an interrupt handler as a protected procedure, and
bind it to a signal via pragma Interrupt_Handler.

Although it's officially obsolescent, you can also bind an interrupt
handler to a task entry.