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

David Holmes david.holmes at oracle.com
Sun Jun 3 20:26:30 PDT 2012

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>> 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>

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/viewbug.do?bugid=7173044 Webrev: http://cr.openjdk.java.net/~zhouyx/7173044/webrev.01/ . -- Best Regards, Sean Chou

-- Best Regards, Sean Chou

More information about the serviceability-dev mailing list