possible threading problem

[Ronald Klop]

On Thu, 3 Jun 2004 17:02:03 -0600, Nate Williams <nate at yogotech.com> wrote:

> [ Note, I have not analyzed the code in question, but from the sounds of
>   things, the behavior the posted is probably 'acceptable' on FreeBSD. ]
>
>> BTW: You interrupt your own thread. The javadoc's say that if the thread
>> is not blocked it will set the interrupted flag. I think that the next
>> time a blocking syscall is done the InterruptedIOException is thrown,
>> because the interrupted flag is set. So the InterruptedIOException can  
>> be
>> thrown at a very different moment than that the thread.interrupt() call
>> was done.
>
> This is right on the money.  Different threading models will behave very
> differently.  Prior to JDK1.4 on Solaris (the reference platform), you
> could get *very* different results by choosing to use green threads
> vs. native threads.  And, things got even more different when you
> started using a JIT, which could cause behavior that appeared to be
> non-deterministic.
>
> In every good Java book, the use of 'interrupt', 'stop', and any other
> method stats that the results you get *WILL* be different.  Just because
> one platform behaves a particular way doesn't necessarily mean it's
> correct (or that any platform is correct).
>
>> I'm not sure about this, because I don't know enough about the
>> internals of java, but it can be the reason, that it looks like a
>> synchronization problem.
>
> In the JVM, or in the code?  (I'm guessing the latter, but I want to
> make sure of your intent).

Yes, I mean the code. And with 'looks like' I mean that it isn't, but it  
makes you think it is a problem in the synchronization. I'll explain: If  
somebody thinks that interrupt() and the InterruptedIOException are  
occuring at the same moment, but the stacktrace of the exception shows the  
program is executing in a part which can never happen at the same moment  
as the interrupt() call (because of synchronized blocks) I can understand  
that somebody gets the idea that synchronization isn't working well.

Greetings,

Ronald.

-- 
  Ronald Klop, Amsterdam, The Netherlands