Fwd: Request for review: 7173044: Memory monitor demo hangs if MemoryUsage obj returns -1 in getMax

[David Holmes]

On 4/06/2012 4:20 PM, Sean Chou wrote:
> Thanks David. Do I need one more reviewer to support as it is a
> modification to demo ?

I honestly don't know. It's a demo in serviceability area, so probably 
someone from serviceability should also give thumbs up.

David

> On Mon, Jun 4, 2012 at 1:55 PM, David Holmes <david.holmes at oracle.com
> <mailto:david.holmes at oracle.com>> wrote:
>
>     Looks okay to me.
>
>     David
>
>
>     On 4/06/2012 3:55 PM, Sean Chou wrote:
>
>         Hi David,
>
>               Thanks for your time, comments are added. The new webrev is
>         http://cr.openjdk.java.net/~__zhouyx/7173044/webrev.02/
>         <http://cr.openjdk.java.net/~zhouyx/7173044/webrev.02/>  .
>         Please have a look.
>
>         On Mon, Jun 4, 2012 at 11:26 AM, David Holmes
>         <david.holmes at oracle.com <mailto:david.holmes at oracle.com>
>         <mailto:david.holmes at oracle.__com
>         <mailto:david.holmes at oracle.com>>> wrote:
>
>             Hi Sean,
>
>             This seems reasonable. Perhaps add a couple of comments:
>
>             125  private float usedMemMax[]; // used when max pool size
>         is undefined
>
>             202  if (totalMemory < 0) {  // max is undefined for this pool
>
>             David
>             -----
>
>
>
>             On 4/06/2012 12:12 PM, Sean Chou wrote:
>
>                 Hello,
>
>                      Would any one like to take one more look ? It will
>         help much !
>
>                 ---------- Forwarded message ----------
>                 From: *Sean Chou* <zhouyx at linux.vnet.ibm.com
>         <mailto:zhouyx at linux.vnet.ibm.com>
>         <mailto:zhouyx at linux.vnet.ibm.__com
>         <mailto:zhouyx at linux.vnet.ibm.com>>
>         <mailto:zhouyx at linux.vnet.ibm.
>         <mailto:zhouyx at linux.vnet.ibm.>____com
>         <mailto:zhouyx at linux.vnet.ibm.__com
>         <mailto:zhouyx at linux.vnet.ibm.com>>>>
>                 Date: Thu, May 31, 2012 at 3:17 PM
>                 Subject: Request for review: 7173044: Memory monitor
>         demo hangs if
>                 MemoryUsage obj returns -1 in getMax
>                 To: serviceability-dev at openjdk.__j__ava.net
>         <http://java.net>
>         <mailto:serviceability-dev at __openjdk.java.net
>         <mailto:serviceability-dev at openjdk.java.net>>
>         <mailto:serviceability-dev@
>         <mailto:serviceability-dev@>__o__penjdk.java.net
>         <http://openjdk.java.net>
>
>         <mailto:serviceability-dev at __openjdk.java.net
>         <mailto:serviceability-dev at openjdk.java.net>>>
>
>
>                 Hi all,
>
>                      MemoryMonitor demo will hang if MemoryUsage obj
>         returns -1
>                 in getMax method.
>                 The demo obtains totalMemory from getMax method, and it
>         is used in
>                 following loop:
>
>         "    // .. Memory Free ..
>                       big.setColor(mfColor);
>                       int MemUsage = (int) (((totalMemory - usedMemory) /
>                 totalMemory) *
>                 10);
>                       int i = 0;
>                       for ( ; i < MemUsage ; i++) {
>                            mfRect.setRect(x1+5,(float) y1+ssH+i*blockHeight,
>                                      blockWidth, blockHeight-1);
>                            big.fill(mfRect);
>                       }
>         "
>                     If -1 is returned, MemUsage becomes a very large
>         positive
>                 value and
>                 the loop hangs
>                 the demo.
>
>                     The bug is not seen in current openjdk because the beans
>                 returned
>                 all has a Max
>                 value returned. However, -1 is allowed by spec when Max
>         is not
>                 set for
>                 the bean, and
>                 other jdk might return.
>
>                     In the patch, max is set to 1m or the max memory
>         usage in
>                 history
>                 for the bean
>                 if there is no max specified. Please take a look.
>
>                 Bug:
>         http://bugs.sun.com/____bugdatabase/view_bug.do?bug_____id=7173044
>         <http://bugs.sun.com/__bugdatabase/view_bug.do?bug___id=7173044>
>         <http://bugs.sun.com/__bugdatabase/view_bug.do?bug___id=7173044
>         <http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7173044>>
>                 Webrev:
>         http://cr.openjdk.java.net/~____zhouyx/7173044/webrev.01/
>         <http://cr.openjdk.java.net/~__zhouyx/7173044/webrev.01/>
>
>         <http://cr.openjdk.java.net/~__zhouyx/7173044/webrev.01/
>         <http://cr.openjdk.java.net/~zhouyx/7173044/webrev.01/>>  .
>
>
>                 --
>                 Best Regards,
>                 Sean Chou
>
>
>
>
>                 --
>                 Best Regards,
>                 Sean Chou
>
>
>
>
>         --
>         Best Regards,
>         Sean Chou
>
>
>
>
> --
> Best Regards,
> Sean Chou
>