PrintGCApplicationStoppedTime

Question

I have JVM option -XX:+PrintGCApplicationStoppedTime which prints real \"GC stop the world time\".

Example:

• Total time for which application threads we

Answer 1

Please note that PrintGCApplicationStoppedTime prints safepoint time rather than GC time.
See this answer for details.

You can get cumulative time of safepoints through JDK-specific (i.e. unsupported) MXBean. This value is equal to the sum of all numbers printed in Total time for which application threads were stopped messages.

sun.management.HotspotRuntimeMBean runtime =
        sun.management.ManagementFactoryHelper.getHotspotRuntimeMBean();

System.out.println("Safepoint time:  " + runtime.getTotalSafepointTime() + " ms");
System.out.println("Safepoint count: " + runtime.getSafepointCount());