Time Stamps

Tom Rodriguez Thomas.Rodriguez at Sun.COM
Tue Jun 12 14:54:39 PDT 2007

The hotspot.log also contains a reference timestamp telling when the VM started.

<hotspot_log version='160 1' process='21174' time_ms='1168494632477'>

time_ms is the same value System.currentTimeMillis() would have returned at the 
point we started the JVM.  All the timestamps should be relative to that time so 
you should be able to convert from that.  Normally the hotspot.log isn't written 
to disk so you'd need to add -XX:+UnlockDiagnosticVMOptions -XX:+LogVMOutput if 
you want to get at it.


Peter B. Kessler wrote:
> Cunningham, Ryan wrote:
>> In the output of the java process's activity there are timestamps, 
>> "6.074: [GC {Heap before gc invocations=0:", and the 6.074 is time 
>> after start of process and I want to change that to human time. I am 
>> not really sure where to go from here. I have searched the files and 
>> have a vague idea of where it comes from.
>> Ryan P Cunningham
>> cunningh at cboe.com
> If you can wait for build 14, you'll find that I've added
>     -XX:+PrintGCDateStamps
> as a fix for
>     6517301: There should be a -XX:+PrintGCDateStamps
>     http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6517301
> which will put an ISO-8601 date and time on the GC output.  E.g.,
>     2007-06-09T12:57:35.093-0700: [GC [PSYoungGen: 4064K->1552K(4928K)] 
> 38770K->36258K(63232K), 0.0590532 secs] [Times: user=0.08 sys=0.00, 
> real=0.06 secs]
> Is that what you wanted to do?  If so, I apologize for preempting
> your doing it, but we already had a bunch of customers that wanted
> that feature.  (Some from large financial traders in Chicago. :-)
> You wouldn't have liked it anyway, since the obvious solution of
> using strftime(3C) doesn't work on Windows.
>             ... peter

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