…data and execute

Some background information: is_ready, take_data and execute data
may be called from different threads in any order. The code in the old
state expected them to be called in series, without interruption.
This lead to multiple race conditions, as the state of the pimpl objects
was altered by the three functions in a non thread safe way.

This commit fixed this by
 - Introducing a data queue that is filled in is_ready
 - take_data from now only pops the front element of the data queue
 - A backlog of events if held in num_unreported_events_ which will be
   reported by future calls of is_ready

Signed-off-by: Janosch Machowinski <J.Machowinski@cellumation.com>

Some background information: is_ready, take_data and execute data
may be called from different threads in any order. The code in the old
state expected them to be called in series, without interruption.
This lead to multiple race conditions, as the state of the pimpl objects
was altered by the three functions in a non thread safe way.

This commit fixed this by
 - Introducing a data queue that is filled in is_ready
 - take_data from now only pops the front element of the data queue
 - A backlog of events if held in num_unreported_events_ which will be
   reported by future calls of is_ready

Signed-off-by: Janosch Machowinski <J.Machowinski@cellumation.com>

Signed-off-by: Janosch Machowinski <J.Machowinski@cellumation.com>

Signed-off-by: Janosch Machowinski <J.Machowinski@cellumation.com>

This function allows us to drop the handle in a locked context.
If we do not do this within a lock, there will be a race condition between
the deletion of the shared_ptr of the handle and the result / feedback
callbacks.

Signed-off-by: Janosch Machowinski <J.Machowinski@cellumation.com>

The capture of the lambda held an copy of the shared_ptr to the
goal handle. This lead to the behavior that the goal callbacks
would be called, even though the user dropped the handle.

Note, this will break the current tutorial, as it restores the documented
behavior that a goal will be invalidated as soon as one drops the handle.

Signed-off-by: Janosch Machowinski <J.Machowinski@cellumation.com>

…dd interface for a callback with TimerInfo argument

Signed-off-by: Alexis Tsogias <a.tsogias@cellumation.com>

…threads

This commit adds external exception handling for the worker threads,
allowing application code to implement custom exception handling.