Re: Integer 128 != Integer 128 ??

From:

Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com>

Newsgroups:

comp.lang.java.programmer

Date:

Tue, 12 Oct 2010 20:25:21 -0700

Message-ID:

<3Pudnfzj7NQ_uyjRnZ2dnUVZ_t8AAAAA@posted.palinacquisition>

Eric Sosman wrote:

[...]
    class Whatever {
        // ...
        private static Integer count = 0;
        static void incrementCount() {
            synchronized(count) {
                count++;
            }
        }
        // ...
    }

.... and then he found that it wasn't working properly. It's my
belief that auto-boxing was entirely responsible for this error:
without auto-boxing, the compiler would have prevented him from
making it in the first place. To put it another way, auto-boxing
silenced a compile-time error and replaced it with a hard-to-debug
run-time error; in my book that's not an improvement.

If your example was:

     class Whatever {
         // ...
         private static int count = 0;
         static void incrementCount() {
             synchronized(count) {
                 count++;
             }
         }
         // ...
     }

???then it would be plausible. :) Integer is a reference type and should
not require boxing for use in the "synchronized" statement.

And yes, even in C#, locking on a value type is a very bad idea. :)

Pete