Haven't looked closely at the change, but thought I would comment
here...

driver_base is designed so that if there is an error, you just go leave
the running state. Driver_base will then automatically try to bring the
whole system back up after a one second pause.

Thus, if you have some way of detecting that the initialization failed,
just don't go to the running state, and all the necessary retries should
happen.

Generally, I see no reason to limit the number of retries. That way you
can unplug and replug the camera, and things will just work.

Cheers,
Blaise

On Tue, 2010-07-13 at 10:56 -0500, Jack O'Quin wrote:
> On Mon, Jul 12, 2010 at 10:14 PM, Jack O'Quin <jack.oquin@gmail.com> wrote:
> > On Mon, Jul 12, 2010 at 4:59 PM, Kim Houck <kim_houck@yahoo.com> wrote:
> >
> >> I like the idea of a 'retries' parameter, either defaulted to 1 or 2 or
> >> to 0.
> >
> > I created a ticket for this problem (#4251)...
> >
> >  https://code.ros.org/trac/ros-pkg/ticket/4251
> 
> On further consideration, I decided Eric was right. There is little
> risk in unconditionally retrying the open a couple of times. For
> cameras that are already working it will have no effect. For those
> inclined to hang when opened with invalid parameters, the open will
> succeed and the camera will hang, just as before.
> 
> Since this is a simple change and it does no harm with my unit test
> cameras, I committed the change to SVN in the camera_drivers trunk.
> There is also a patch attached to ticket #4251. None of my cameras
> require retries, but they tolerate them just fine.
> 
> @Kim: Would you please:
> 
>  (1) check out  https://code.ros.org/svn/ros-pkg/stacks/camera_drivers/trunk
>  (2) put it in front of cturtle in your $ROS_PACKAGE_PATH
>  (3) rosmake camera1394
>  (4) test it with your Sony DFW-X710
> 
> If you are using cturtle from svn and not binaries, it might be
> simpler to just patch your copy of the driver and rebuild. Either
> approach should work. If you have questions, please ask.
> 
> If this fix works for you, we can close the ticket and release it in
> the next cturtle update.
> 
> Thanks for helping,