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

[Sean Chou]

Thanks David. Do I need one more reviewer to support as it is a
modification to demo ?

On Mon, Jun 4, 2012 at 1:55 PM, David Holmes <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 <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 <zhouyx at linux.vnet.ibm.com>>
>>        <mailto:zhouyx at linux.vnet.ibm.**__com
>>        <mailto:zhouyx at linux.vnet.ibm.**com <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@**openjdk.java.net<serviceability-dev at openjdk.java.net>
>> >
>>        <mailto:serviceability-dev at __o**penjdk.java.net<http://openjdk.java.net>
>>
>>        <mailto:serviceability-dev@**openjdk.java.net<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
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