[ntp:questions] Befuddled and confused, again...

unruh unruh at wormhole.physics.ubc.ca
Tue Feb 16 16:55:47 UTC 2010


On 2010-02-16, Rob <nomail at example.com> wrote:
> unruh <unruh at wormhole.physics.ubc.ca> wrote:
>> Now, I am not sure whether gpsd will run on bsd, but I suspect it should
>> not be hard to convert it to do so. The ioctl calls to the serial port
>> or parallel port may well be different, but there are very few of them
>> in the code. 
>
> There may be few of them, but one is very essential.
> When there is no equivalent of TIOCMIWAIT available in your os, it will
> be very hard to convert the code.
>
> TIOCMIWAIT is the ioctl that returns precisely at the moment when a
> handshake line (passed as a parameter) changes state.  This is
> functionality you cannot simply emulate by calling some other ioctls.

And you are trying to claim that BSD has no equivalent functionality?
I simply do not believe that. It may be called something else, but that
is what "convert" means.

Besides it cannot return at "precisely" the moment. If it polls, it
depends on how long the poll intrval is. Only a few of the lines are
interrupt driven and I still do not know if TIOCMIWAIT uses interrupts
if they are available. 
 




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