Re: volatile long

Hanson Char wrote:
> Thanks Joe, I did some experiment and the result is on your side.  The
> ++count is a read-modify-write operation, not a pure write operation. 
> So volatile will never work with such construct.
> 
> Hanson

Yup, volatile only makes the reads and writes atomic, not combinations
of reads and writes.  And ++ is definitely a read and a write (how else
will it know the value to increment?).  In case you're interested,
here's an example execution of how you can get count to be negative:

count initially 0

Thread 1                       Thread 2

read count (0)
                               read count (0)
                               write count = 1
write count = 1
read count (1)
write count = 0
                               read count (0)
                               write count = -1


- Victor