The TimeSource subscribes to /clock topic and publishes the time to all
attached clocks (by default only clock used by create_timer is attached).
This module is feature gated because the clock is published in message
rosgraph_msgs::msg::Clock and rosgraph_msgs needs to be specified as
dependency by the end users.
Added feature flag sim-time because functions that are feature gated does
not make sense without TimeSource that is implemented in later commit
and needs the feature flag.
This adds Node::create_timer() method. The method is similar to
already existing Node::create_wall_timer(), but the timer is based on
ClockType::RosTime rather than on ClockType::SteadyTime.
The advantage of ClockType::RosTime is that one can drive the clock
from a different time source. This will be used in the next commits to
implement for clock source on the /clock topic.
This commit is preparation for next commit with timer using RosTime clock.
In the previous implementation the function rcl_timer_init is called
with zero initialized timer handle being stored on stack and after
initialization with rcl_timer_init the timer handle is moved by rust
inside Timer_ struct.
The problem occurs if the type of clock being passed to rcl_timer_init()
is RosTime because the function also registers callbacks in the clock
that would notify the timer about sudden time change (jump callback).
In RCL the jump callback is registered with rcl_clock_add_jump_callback()
and the argument callback.user_data is pointer to timer handle that in
our case references timer stored om stack. When returning from function
create_wall_timer() the pointer becomes dangling and therefore when the
callback is actually called (by function _rcl_timer_time_jump) it could
result in SIGSEGV or could access some variable that happens to be in
the same place as the timer_handle was on stack.
This is fixed by storing timer_handle inside pinned box to prevent
moving the handle.
* Add raw publisher
* Add raw publisher examples
* Add more tests. Convert Context into singleton to avoid memory corruption when creatin multiple Context instances
Martin Škoudlil
Martin Dahl
Földi Tamás
NerdToMars
Michael Hoy
Alec Rivers