bug: https://bugs.openjdk.java.net/browse/JDK-8154710 webrev: http://cr.openjdk.java.net/~dholmes/8154710/webrev/
This change is small in nature but somewhat broad in scope. It "affects" the implementation of System.currentTimeMillis() in the Java space, and os::javaTimeMillis() in the VM. But on Solaris only.
I say "affects" but the change will be unobservable other than in terms of performance.
As of Solaris 11.3.6 a new in-memory timestamp has been made available (not unlike what has always existed on Windows). There are actually 3 different timestamps exported but the one we are interested in is get_nsecs_fromepoch - which is of course elapsed nanoseconds since the epoch - which is exactly what javaTimeMillis() is, but expressed in milliseconds. The in-memory timestamps have an update accuracy of 1ms, so are not suitable for any other API's that want the time-of-day, but at a greater accuracy.
Microbenchmark shows the in-memory access is approx 45% faster (19ns on my test system) compared to the gettimeofday call (35ns).
Thanks, David
