[PD] pd and serial object
Winfried Ritsch
ritsch at iem.kug.ac.at
Thu Apr 25 12:04:57 CEST 2002
hello,
[...]
>
> in mail http://iem.kug.ac.at/mailinglists/pd-list/2001-12/0159.html
> from mark newman seems to be a solution for the win2k comport
> object:
> //////////////////////////////////////////////////////////////
> I grabbed Winfried Ritsch's comport object and code from
> http://iem.kug.ac.at/ritsch/programmier/pd_externals/
>
[...]
> fd = CreateFile( sys_com_port[com_nr],
> rw,
> 0,
> 0,
> OPEN_EXISTING,
>
> /* FILE_FLAG_OVERLAPPED */ 0, // changed to non-overlapped
> --mwn
> 0);
>
> ... and now it works. I believe this is the correct way to open the
> port, since the code is in fact polling (every millisecond, by default)
> and not in fact using asynchronous reads. Changing the object to use
> overlapped/asynchronous reads would probably be an even better fix, but
> that'll have to be for another time.
the problem I saw (read), that there is no garantuee that with this
fix the serial will not block for a amount of time (like it does on
W95 up to 10ms if I set this) since "no overlap" means in my opinion
that it waits for a input until time out (at least a win scheduler
tick), but maybe it is correct anyway...
can anyone confirm if "overlap" is not needed on Win platforms for i/o?
I have no w2k plattform to test, just want to release a working version.
thanks
mfg winfried
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