Looks good! Thanks, /Staffan
On 2 okt 2013, at 10:47, Jaroslav Bachorik <jaroslav.bacho...@oracle.com> wrote: > Hello, > > currently the JVM uptime reported by the RuntimeMXBean is based on > System.currentTimeMillis() which makes it susceptible to changes of the OS > time (eg. changing timezone, NTP synchronization etc.). The uptime should not > depend on the system time and should be calculated using a monotonic clock > source. > > There is already the way to get the actual JVM uptime in ticks. It is > accessible as Management::timestamp() and the ticks are convertible to > milliseconds using Management::ticks_to_ms(ts_ticks) thus making it very easy > to switch to the monotonic clock based uptime. > > The patch consists of the hotspot and jdk parts. > > For the hotspot a new constant needs to be introduced in > src/share/vm/services/jmm.h and the actual logic to obtain the uptime in > milliseconds is added in src/share/vm/services/management.cpp. > > For the jdk the changes comprise of adding the necessary JNI bridging methods > in order to get the new uptime, introducing the same constant that is used in > hotspot and changes to mapfile-vers files in order to properly build the > native library. > > Issue: https://bugs.openjdk.java.net/browse/JDK-6523160 > Webrev: http://cr.openjdk.java.net/~jbachorik/6523160/webrev.00 > > Thanks, > > -JB-
