Re: Note on PushbackInputStream

[Tom Tromey]

>>>>> "Dalibor" == Dalibor Topic <address@hidden> writes:

>> I can't see a way out of the situation either, without creating some
>> kind of dual block (block on *either* the pushback or the underlying
>> stream) or possibly setting a time interval to periodically come back
>> from the underlying stream and check the pushback.

Dalibor> I came up with the following pseudo-code:
Dalibor> [ ... ]

Dalibor> Thread A tries to read a single byte, and blocks. it keeps
Dalibor> acquiring and releasing the lock for the pushbackinputstream
Dalibor> while it blocks.

I think polling like your loop does is a bad idea.  I would be very
reluctant to put code like that into the library.

I don't think this is actually a very important bug in practice.  I'm
sure Sun's implementation has it too.  I just thought it was
interesting from a design point of view.

Dalibor> If you've got this far, I'd like to hear comments :-) I think
Dalibor> that in a cooperative multi-threading environment the yield()
Dalibor> is necessary, since otherwise thread B might not be able to
Dalibor> get any CPU time to unread the byte, but I'm not sure.

Thread.yield() isn't guaranteed to do anything.

Tom