Hi
Could u pls Tell me what are the
calls form stdlib.h, math.h one
should not use from rtspace.
or
pls tell me where can i get in a document form
thanks
chandu
-----Original Message-----
From: Norm Dresner [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, September 18, 2001 10:06 PM
To: [EMAIL PROTECTED]
Subject: Re: [rtl] doubt regd library calls
Not quite.
There is a big difference between "Library Calls"
and "System Calls". Some Library calls are
nothing much more than calls to your own
functions. System Calls are what you're referring
to. There are library calls that are safe to make
and library calls that call system calls that are
not usable in a real-time module. You can safely
use some functions from libgcc that make no system
calls -- many of the math functions that aren't
compiled in-line are like that. But you can't use
the normal sprintf (because it uses malloc).
Norm
----- Original Message -----
From: Calin A. Culianu <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Tuesday, September 18, 2001 12:06 PM
Subject: Re: [rtl] doubt regd library calls
>
> No library calls are being made in RTLinux, per
se. In fact, such a thing
> would be quite difficult to do from kernel
space. You'd basically have to
> mimic the entire system call interface in kernel
space, and probably do
> other magic just to be able to statically link a
library in to a kernel
> extension. Yikes!
>
> No, what actually happens is that RTLinux has a
clean, and quite standard,
> pthread interface to make the difficult task of
writing multi-threaded
> kernel modules somewhat easier and more
manageable for people not used to
> kernel programming. The result is that you get
those pthread_* functions
> in kernel space, but that is just an interface.
What happens under the
> hood has nothing to do with user-space
libraries.
>
> -Calin
>
> On Thu, 13 Sep 2001, A V wrote:
>
> > hi everybody,
> >
> > I have some doubt about library calls. I read
in OS
> > concepts that kernel space program should not
make
> > references to user space processes. Am i right
?
> > In RTLniux, every realtime module runs in
Kernel
> > space. And we are making library calls to
create
> > threads which runs in User space. but
according to OS
> > concepts process running in Kernel space
should not
> > refer User space..
> > Please clarify my doubt..
> >
> > Regards
> > Venkat
> >
> >
> >
> >
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