system_shutdown
System shutdown handler
This is a node in system package that handles system shutdown based on ros parameters
Flags and Settings
| Name | Description |
|---|---|
/system/shutdown/flags/running | Shutdown node has been started. Example file: demoD.yaml |
/system/shutdown/flags/initialized | Shutdown node has been initialized. Example file: demoD.yaml |
Inputs
Following are the argument required by the node
| Name | Description |
|---|---|
/system/shutdown/params/shutdown_initiation_flags | List of parameters that are constantly monitored for their truth values. If any of these becomes true, system shutdown would be initiated. Example file: demoD.yaml |
/system/shutdown/params/shutdown_completion_flags | List of parameters which inidicate pre-processing required for a safe shutdown. Only when all the parameters become true, ros system would be shutdown. Example file: demoD.yaml |
Output
If any of the shutdown_initiation_flags becomes true, then a shutdown routine will be initiated. The node would then wait for all shutdown_completion_flags to become true. Once it is achieved, this node would shutdown. Since system_shutdown is always added as a required node in a launch file, the ros system would kill all remaining nodes which were spawned through this launch file.
Example use case
Put following code in launch file:
<?xml version="1.0"?>
<launch>
<arg name="system_params_path" default="$(find system)/config/system/demos/demoD.yaml"/>
<!-- Add your nodes -->
<node name="system_shutdown" pkg="system" type="system_shutdown" output="screen" required="true">
<rosparam file="$(arg system_params_path)" command="load"/>
</node>
<node name="bootstrap" pkg="system" type="bootstrap.jl" output="screen"/>
</launch>Put following code in your system.yaml. Note: Do not use this directly, this is just an example and shows only relevant components for shutdon node.
system:
flags:
override_shutdown_hook: false
data_logging_completed: true
shutdown:
flags:
running: true
initialized: false
params:
shutdown_initiation_flags: ["system/flags/goal_attained", "/vehicle_collided"]
shutdown_completion_flags: [system/flags/data_logging_completed]