On Sep 26, 2013, at 11:50 AM, Christian Thalinger <christian.thalin...@oracle.com> wrote:
> > On Sep 26, 2013, at 1:22 AM, Peter Levart <peter.lev...@gmail.com> wrote: > >> 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… > > Not sure it would be cleaner; depends on the definition of "cleaner". I had > similar code as you describe before but I changed it to catch the exception. > If people have a strong opinion here I can change it back. Here are the two different versions: http://cr.openjdk.java.net/~twisti/8019192/webrev.00/ http://cr.openjdk.java.net/~twisti/8019192/webrev.01/ > >> >> Regards, Peter >> >
