Re: [Sablevm-developer] java.lang.Thread.yield()

[Prof. E. M. G. <eti...@uq...>]

On Wed, Feb 19, 2003 at 10:24:44PM -0500, Chris Pickett wrote:
> Well it's used all over the place in your code and I thought it would=20
> help me to understand it better.  The reason I included it in that=20
> function was because there are many other uses of JNI_OK in=20
> java_lang_Thread.c.

OK.

> Bruno just answered my question, so it's probably a good idea if I look=
=20
> at jni.h a bit.

You should read the JNI specification book.  It is very well written.
It has a first part that explains how to use the JNI interface from a
programmer's perspective (giving much insight on the reason why things
are setup that way), and the second part is the specification itself.

This is where JNI_OK is really defined.  The JNI interface has had a
very deep impact on the architecture of SableVM.  This is why I think
you should read the document (in addition to reading the JVM
specification, of course).

jni.h encodes what is specified in the JNI book.

> Okay, sched.h conforms to POSIX.1b, but it's still the GNU C library, so=
=20
> if you don't want dependence on sched.h then use pthread_yield().  They=
=20
> do the same thing . . .

The GNU C library (commonly called glibc or libc6) implements the
standard C library + POSIX + other things + GNU extentions.

You simply have to restrict yourself to using Standard C + POSIX
compatible calls.

=2E..
> And so I figured it was a pretty bad thing if the yield() didn't work=20
> because it says pathological, so I thought killing the VM was reasonable.

If you look at my solution, you'll note that I suggest that we might
simply ignore the return value anyway.  This is why your original code
semmed OK to me (I was assuming you had already investigated about
return values & POSIX compliance).

Have fun.

Etienne
--=20
Etienne M. Gagnon, Ph.D.             http://www.info.uqam.ca/~egagnon/
SableVM:                                       http://www.sablevm.org/
SableCC:                                       http://www.sablecc.org/