Realtime Linux


Johan Bengtsson


Curt Wuollet

Hi Mark

It's kinda early to tell. I'm not sure POSIX threads give us anything under Linux except portability. Threads are, for whatever reason, not
emphasised in the Linux kernel. This has been an issue for Java and a few other areas. I'd lean towards the emerging ELIX standard for
embedded compatibility. Stick around and then we'll know if we break QNX compatibility. QNX has been making some good noises lately about moving a little towards the open camp. That should make
things somewhat easier. Linux aims at being POSIX compliant, but not at the cost of performance or technical excellence. I may try to
put QNX on a box. I've been curious, but, it was too expensive to play with. They aren't really open, but they're trying to adjust to the changing landscape.



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mark tompkins wrote:
> What is the API target for portability between different UNICES? Will
> the PuffinPLC use POSIX API only? Will it use POSIX threads?

Right now, it's not using threads at all; there are some arguments pro and con, but mostly it's just that processes are better-known.

It's using SysV shared memory and semaphores.

> I'd like to run the PuffinPLC on QNX Neutrino.

As Curt wrote - stick around! If we do something non-portable, I guess it's better to find out sooner than later...

(The project's primary target platform is Linux; however, if all that's needed for portability is a wrapper function and an #ifdef...)

Obviously, the kernel drivers won't be much use to you, but much of the ethernet and serial I/O will probably be in ordinary user processes (for
much the same reasons we don't like threads).

Jiri Baum <[email protected]>
Windows is not popular. Windows is *widespread*. Linux is popular.

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