Thanks Yasumasa and JC for looking at this. I noticed that we seem to do
the same thing in ReversePtrsAnalysis.java, i.e. call
heapIterationFractionUpdate(0) to get things initialized. So, let's go
with webrev.0.
cheers,
Per
On 09/13/2018 07:31 PM, JC Beyler wrote:
Looks like webrev.0 is the good one then :); looks good to me then Per
(not a reviewer though),
Jc
On Thu, Sep 13, 2018 at 6:25 AM Yasumasa Suenaga <yasue...@gmail.com
<mailto:yasue...@gmail.com>> wrote:
Hi Per,
On 2018/09/13 19:48, Per Liden wrote:
> Hi JC,
>
> Thanks for reviewing.
>
> On 09/12/2018 06:02 PM, JC Beyler wrote:
> > Hi Per,
> >
> > I do not know this code but your need to
> > call?heapIterationFractionUpdate seems to be a code smell that
> > something
> > else could be fixed, no?
> >
> > Your webrev looks fine to me if I ignore the code smell that
comes
> > from
> > having to call the update call:
> >
> > When I look at
> >
src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/HSDB.java, the
> > reason it requires that first call is, like you said, that
the frame
> > is
> > created only at the first heapIterationFractionUpdate.
However, could
> > we
> > not test frame and if it is not created, don't try to remove it?
>
> I actually did that initially, but had the feeling people would
think
> that was an even worse code smell ;) I don't have a strong
opinion on
> this, so I updated the webrev to check for null instead.
>
> http://cr.openjdk.java.net/~pliden/8209163/webrev.1
I perfer to webrev.0 because `frame` should be initialized in
ProgressiveHeapVisitor#prologue().
According to [1], HeapProgress which is used for progress bar will
initialize inner frame when it is null. IMHO the inner frame should
be initialized at ProgressiveHeapVisitor#prologue().
Thanks,
Yasumasa
[1]
http://hg.openjdk.java.net/jdk/jdk/file/8abb0fa2c334/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/HSDB.java#l1689
> cheers,
> Per
>
> >
> > Thanks,
> > Jc
> >
> > On Wed, Sep 12, 2018 at 1:25 AM Per Liden <per.liden at
oracle.com <http://oracle.com>
> > <mailto:per.liden <mailto:per.liden> at oracle.com
<http://oracle.com>>> wrote:
> >
> > This patch avoids an assertion, and instead prints a warning,
> > when
> > trying to show the "Object Histogram" when using ZGC. I
also had
> > to add
> > a call to heapIterationFractionUpdate() so that the update
> > progress
> > frame is properly created, even when there are not heap
regions
> > to walk
> > over. Without this, you only get a call to
> > heapIterationCompleted(),
> > with a null frame, which throws a NullPointerException.
Always
> > making a
> > call to heapIterationFractionUpdate(0.0) in the prologue
avoids
> > this by
> > making sure we always created the frame, even if no more
fraction
> > updates will happen.
> >
> > Bug: https://bugs.openjdk.java.net/browse/JDK-8209163
> > Webrev: http://cr.openjdk.java.net/~pliden/8209163/webrev.0
> >
> > /Per
> >
> >
> >
> > --
> >
> > Thanks,
> > Jc
>
--
Thanks,
Jc
