sun/jvm/hotspot/oops/Symbol.java

[Andrew Haley]

On 05/12/2015 03:47 PM, Andrew Haley wrote:
> On 04/28/2015 09:00 PM, Dmitry Samersoff wrote:
>> Thank you for the fix, I'll take a look at it
> 
> Hi,
> 
> Any thoughts?  HSDB doesn't really do anything without this fix, and
> there is no doubt that the bottom two bits of a Symbol address must be
> masked out.
> 
> The only problem I have is deciding where to do the masking.  Doing in
> when we create an instance of Symbol from an address always works, but
> I'm not sure it's the right thing to do.

For what it's worth, this may be a better patch.  It works just as well,
and it is only applied to cpool entries.

Andrew.



diff -r f39a03c0ced3 agent/src/share/classes/sun/jvm/hotspot/oops/ConstantPool.java
--- a/agent/src/share/classes/sun/jvm/hotspot/oops/ConstantPool.java    Tue May 12 16:14:34 2015 +0100
+++ b/agent/src/share/classes/sun/jvm/hotspot/oops/ConstantPool.java    Tue May 12 16:23:00 2015 +0100
@@ -170,7 +170,7 @@
   }

   public Symbol getSymbolAt(long index) {
-    return Symbol.create(getAddressAtRaw(index));
+    return Symbol.create(getAddressAtRaw(index).andWithMask(~3));
   }

   public int getIntAt(long index){