On Wednesday 04 May 2011 16:35:36 Willy Lambert wrote:
> Hi,
>
> What is the way to play with time inside a component ? Is it something in
> Orocos or should I use standard Linux services ? Basically what I whant to
> do is to check for how long a data has not been published in a port :
>
> if(NewData==inPort(cmd))
> {
> // manage cmd
> ...
> }
> else
> {
> //if we didn't receive something for a long time go into panic !
> ....
> }
>
>
> I read this in the component builder manual :
>
> 4. Time Measurement and Conversion
> 4.1. The TimeService
>
> The
> TimeService<http://www.orocos.org/stable/documentation/rtt/v2.x/api/html/cl
> assRTT_1_1os_1_1TimeService.html> is implemented using the Singleton design
> pattern. You can query it for the current (virtual) time in clock ticks or
> in seconds. The idea here is that it is responsible for synchronising with
> other (distributed) cores, for doing, for example compliant motion with two
> robots. This functionality is not yet implemented though.
>
> When the
> SimulationThread<http://www.orocos.org/stable/documentation/rtt/v2.x/api/ht
> ml/classRTT_1_1extras_1_1SimulationThread.html> is used and started, it will
> change the TimeService's clock with each period ( to simulate time
> progress). Also other threads (!) In the system will notice this change,
> but time is guaranteed to increase monotonously.
>
> 4.2. Usage Example
>
> Also take a look at the interface documentation.
>
> #include <rtt/os/TimeService.hp

> #include <rtt/Time.hp

>
> TimeService::ticks timestamp =
> TimeService<http://www.orocos.org/stable/documentation/rtt/v2.x/api/html/cl
> assRTT_1_1os_1_1TimeService.html>::Instance()->getTicks();
>
> //...
>
> Seconds elapsed = TimeService::Instance()->secondsSince( timestamp );
>
> Is it still up to date ? Shall I use this ?

I have been and still am using this to do time measurements in my component.
You could also take a look into the TimerComponent:
This is the API docs, I don't know whether it is documented elsewhere too:
http://www.orocos.org/stable/documentation/ocl/v2.x/api/html/classOCL_1_...

-- Ruben