Service

class olaf.ServiceState(value)

State a service can be in.

STOPPED = 0

Service is not running.

STARTING = 1

Service is starting up.

RUNNING = 2

Service is running.

STOPPING = 3

Service is stopping.

FAILED = 3

Service has failed.

class olaf.Service

OLAF service, basically a Resource with a dedicated thread.

All the on_* members can be overridden as needed.

node

The app’s CANopen node. Set to None until start() is called.

Type:

Node or MasterNode

start(node: Node)

App will call this to start the service. This will call self.on_start() start a thread that will call self.on_loop().

on_start()

Called when the service starts.

Should be used to add SDO read/write callbacks to app.

on_loop()

Called when in a while loop.

on_loop_error(error: Exception)

Called when on_loop raises an exception before the thread stops.

Should be used to stop any hardware the service controls (if possible) and logs the errors.

stop()

App will call this to stop the service when the app stops. This will call self.on_stop().

on_stop_before()

Called when the app stops before the thread is stopped. Should be used to stop any blocking calls in the thread loop.

Will be called reguardless if self.on_loop_error() was called or not when the app stops.

on_stop()

Called when the app stops after the thread has stopped. Should be used to stop any hardware the service controls.

Will be called reguardless if self.on_loop_error() was called or not when the app stops.

sleep(timeout: float)

Sleep for X seconds, that can be interupted if stop() is called.

Parameters:

timeout (float) – The time to sleep in seconds.

sleep_ms(timeout: float)

Sleep for X milliseconds, that can be interupted if stop() is called.

Parameters:

timeout (float) – The time to sleep in milliseconds.

cancel()

Cancel the service. Can be used to stop the service from self.on_loop().

property status: ServiceState

Get the service state.

Type:

ServiceState