Small improvements to nio native code (unix)

[Alan Bateman]

Martin Buchholz wrote:
> Hi Alan,
>
> I'd like you to do a code review.
>
> Avoid problematic JNI *Critical functions.
> Fix rawtypes compile warnings.
> Make IOUtil native code more readable.
> Rename initPipe to makePipe.
> Rename "block" argument to "blocking" for consistency.
>
> http://cr.openjdk.java.net/~martin/webrevs/openjdk7/IOUtil/ 
> <http://cr.openjdk.java.net/%7Emartin/webrevs/openjdk7/IOUtil/>
>
> Thanks,
>
> Martin
It makes sense to return the two file descriptors in a jlong rather than 
using a JNI critical section (although they aren't as bad as they used 
to be in that a thread requiring a GC because an allocation cannot be 
satisfied will now stall rather than throw OOME).

Anyway, the changes look okay to me. I've created this bug:
  6981145: (se) Eliminate JNI*Critical when creating pipes and other 
cleanups

Minor nit but at line IOUtil.c L140 you've got "const char * msg" (space 
on either side of the asterisk).

In passing, I see in Java_sun_nio_ch_IOUtil_makePipe doesn't close the 
pipe in the highly unlikely event that the configureBlocking fails. It 
might be good to fix that while you are there (if you don't mind of course).

-Alan.