RFR: JDK-8160997 Solaris: deprecated <pwd.h> and <gid.h> interfaces should be replaced

[Daniel D. Daugherty]

On 7/14/16 1:52 AM, Alan Burlison wrote:
> On 14/07/2016 02:20, David Holmes wrote:
>
>> One query: if pwd.h is not the last file included don't we need to undef
>>   _POSIX_PTHREAD_SEMANTICS again to ensure no other included definitions
>> are affected? If we don't need to do that then I wonder whether
>> _POSIX_PTHREAD_SEMANTICS should not simply be set via the build system
>> for all compilations?
>
> _POSIX_PTHREAD_SEMANTICS only affects a few APIs which changed between 
> POSIX.1c Draft 6 and POSIX 1003.1c - Solaris implemented the draft 
> version due to release scheduling issues, which was a mistake. Some of 
> the differences don't matter for LP64 apps such as Java, the other 
> APIs are less-frequently used. The main problems you tend to see are 
> the user/group iteration APIs (as in this case) and directory 
> enumeration. You could undef _POSIX_PTHREAD_SEMANTICS if you wanted 
> but there's no real benefit and it would add yet more clutter.

If we #undef'ed it right after the one or two header files that we intend
it to affect, then our intentions would be more clear. Yes, it will add
one more line of "clutter", but I think clarity is more important.

I also think this can be done as a pre-push change and does not need to
go through yet another round of testing.

Dan


>
> As for setting it globally, no that wouldn't be a good idea. It's a 
> workaround for a problem that will be gone in later Solaris releases, 
> where you'll get the POSIX 1003.1c definitions by default and will 
> have to explicitly ask for the old draft ones. At that point defining 
> _POSIX_PTHREAD_SEMANTICS will have no effect. It is a transitional 
> workaround for a misfeature and as such I believe needs to be 
> restricted as much as possible by just adding it to the affected 
> files, and then removing it altogether as soon as possible.
>