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

[David Holmes]

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/  . 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>> 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>>>
>         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.__java.net
>         <mailto:serviceability-dev at 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>
>         Webrev: 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
>