JDK 17: First Release Candidate

[Florian Weimer]

* David Holmes:

>>> That seems like a glibc bug to me as SIGSTKSZ is supposed to be a constant.

>> It is still a constant in glibc's POSIX mode, but OpenJDK does not
>> use POSIX mode (with good reason).
>
> Can you elaborate on what that good reason is please? If this is
> something critical then it really needs to be documented somewhere. It 
> makes me uncomfortable that we have spent a lot of time cleaning up
> hotspot runtime code to provide shared "posix" implementations, if we 
> may not even be getting Posix semantics.

glibc's POSIX mode removes all declarations and definitions from its
header files which are not part of the requested POSIX version (at least
in theory; there are of course bugs).  This is based on what is in the
actual standard, not on what typical implementations support.

For example, the functions lseek64 and ftruncate64 are used in
src/hotspot/os/posix/os_posix.cpp but are not part of any POSIX version.
gethostbyname is no longer part of POSIX, either.

Thanks,
Florian