Re: question about Common C++ 2 serial class

[David Sugar]

I believe you should be able to use the isPending method to test if the
device is writable (isPending(SERIAL_PEND_OUTPUT, maxtime)) to safely test
if you can use this->flush with a timeout.  flushOutput() is meant to
flush the device i/o queue and wait for i/o completion rather than the
stream buffer.  The aRead and aWrite methods may also be overriden in a
derived class, and can be replaced with async i/o routines depending on
your environment.

David

On Wed, 16 Oct 2002, Tim Esselens wrote:

> Hi,
> 
> I've been using your serial class for a HA (high availability) project. I've 
> managed to get 2 machines to ping eachother over serial line. But there is a 
> rather big problem coming up. If I flush (this->flush()) my object 
> (SerialBeat: public TTYSession) the thread blocks, flushOutput() doesn't seem 
> to be flushing at all.
> 
> So, the problem I'm having is quite simple, how to flush in a nonblocking 
> kind 
> of mode, so after n msecs of 'unflushability' it could start throwing errors.
> I only hope the answer is as easy as the question.
> 
> If this is not possible for some reason, is there a way around this (still 
> using your serial class ofcourse)? I need to detect the other side is down, 
> that's really it (maybe something the serial protocol allready includes, but 
> I'm new to serial lines, so I wouldn't know).
> 
> kind regards,
> Tim Esselens
> 
> ps: NEWS stated sending questions to dyfet, README to bug-commoncpp, I did 
> both <g>
>