RFR: 8194860: Cleanup Semaphore timed-wait time calculations

[David Holmes]

Withdrawn temporarily.

The OS X changes were still being tested and they don't work. For some 
reason we're using kernel semaphores on OS X and they seem to take a 
relative timeout directly. That explains why they had a different API 
but doesn't help with the fact that the calling code expects 
OSXSemaphore and PosixSemaphore to have the same API.

David

On 17/01/2019 8:06 am, David Holmes wrote:
> bug: https://bugs.openjdk.java.net/browse/JDK-8194860
> webrev: http://cr.openjdk.java.net/~dholmes/8194860/webrev/
> 
> Details in the bug report, but there was duplication in functionality 
> with regards to timeout conversions/calculations, and the os_bsd.cpp 
> code was broken due to OSXSemaphore and PosixSemaphore having different 
> API's.
> 
> Summary:
> - expanded the API to take a relative timeout in millis as well as the 
> existing absolute timeout as a timespec:
> 
>    // wait until the given absolute time is reached
>    bool timedwait(struct timespec ts);
>    // wait until the given relative time elapses
>    bool timedwait(int64_t millis);
> 
> The millis version simply converts to a timespec and calls the other 
> version e.g
> 
> bool PosixSemaphore::timedwait(int64_t millis) {
>    struct timespec ts;
>    os::Posix::to_RTC_abstime(&ts, millis);
>    return timedwait(ts);
> }
> 
> - added os::Posix::to_RTC_abstime to do the relative to absolute 
> conversion using the existing routines in os::Posix used for 
> PlatformEvent etc.
> 
> - changed callsites to use new millis version
> 
> - I had to rearrange the ifndef SOLARIS in os_posix.cpp to expose 
> previously hidden code to Solaris. It isn't all needed by Solaris but I 
> chose not to clutter things with too many ifdefs and only excluded 
> things that really shouldn't be done on Solaris. Also needed to call 
> os::Posix::init on Solaris.
> 
> Testing (still in progress):
> - mach 5 tiers 1 - 3 (Linux, Solaris, OS X, Windows)
> - test/jdk/jdk/jfr (as suspend/resume is the user of the semaphore code)
> 
> Thanks,
> David