On 09/26/2013 01:27 AM, Christian Thalinger wrote:
http://cr.openjdk.java.net/~twisti/8019192/webrev/

8019192: StringIndexOutOfBoundsException: in Class.getSimpleName()
Reviewed-by:

This is a race in MemberName's name and type getters.

MemberName's type field is of type Object so it can hold different objects when 
it gets filled in from the VM.  These types include String and Object[].  On 
the first invocation the current type if it's not MethodType gets converted to 
a MethodType.

There is a tiny window where some instanceof check have already been done on 
one thread and then another thread stores a MethodType.  The following 
checkcast then fails.

The fix is to make name and type volatile and do the conversion in a 
synchronized block.  This is okay because it's only done once.

src/share/classes/java/lang/invoke/MemberName.java


Hi Christian,

Wouldn't it be cleaner that instead of just casting and catching ClassCastException, the volatile field 'type' was 1st copied to a local variable and then an instanceof check + casting and returning performed on the local variable. This would avoid throwing ClassCastException even if it is performed only once per MemberName...

Regards, Peter

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