Services

Client

class rclpy.client.Client(context, client_handle, srv_type, srv_name, qos_profile, callback_group)

Create a container for a ROS service client.

Warning

Users should not create a service client with this constuctor, instead they should call Node.create_client().

Parameters

  • context (Context) – The context associated with the service client.

  • client_handle – Handle wrapping the underlying rcl_client_t object.

  • srv_type (~SrvType) – The service type.

  • srv_name (str) – The name of the service.

  • qos_profile (QoSProfile) – The quality of service profile to apply the service client.

  • callback_group (CallbackGroup) – The callback group for the service client. If None, then the nodes default callback group is used.

call(request)

Make a service request and wait for the result.

Warning

Do not call this method in a callback or a deadlock may occur.

Parameters

request (~SrvTypeRequest) – The service request.

Return type

~SrvTypeResponse

Returns

The service response.

Raises

TypeError if the type of the passed request isn’t an instance of the Request type of the provided service when the client was constructed.

call_async(request)

Make a service request and asyncronously get the result.

Parameters

request (~SrvTypeRequest) – The service request.

Return type

Future

Returns

A future that completes when the request does.

Raises

TypeError if the type of the passed request isn’t an instance of the Request type of the provided service when the client was constructed.

destroy()
property handle
remove_pending_request(future)

Remove a future from the list of pending requests.

This prevents a future from receiving a response and executing its done callbacks.

Parameters

future (Future) – A future returned from call_async()

Return type

None

service_is_ready()

Check if there is a service server ready.

Return type

bool

Returns

True if a server is ready, False otherwise.

wait_for_service(timeout_sec=None)

Wait for a service server to become ready.

Returns as soon as a server becomes ready or if the timeout expires.

Parameters

timeout_sec (Optional[float]) – Seconds to wait. If None, then wait forever.

Return type

bool

Returns

True if server became ready while waiting or False on a timeout.

Service

class rclpy.service.Service(service_handle, srv_type, srv_name, callback, callback_group, qos_profile)

Create a container for a ROS service server.

Warning

Users should not create a service server with this constuctor, instead they should call Node.create_service().

Parameters

  • context – The context associated with the service server.

  • service_handle – Capsule pointing to the underlying rcl_service_t object.

  • srv_type (~SrvType) – The service type.

  • srv_name (str) – The name of the service.

  • callback_group (CallbackGroup) – The callback group for the service server. If None, then the nodes default callback group is used.

  • qos_profile (QoSProfile) – The quality of service profile to apply the service server.

destroy()
property handle
send_response(response, header)

Send a service response.

Parameters

  • response (~SrvTypeResponse) – The service response.

  • header – Capsule pointing to the service header from the original request.

Raises

TypeError if the type of the passed response isn’t an instance of the Response type of the provided service when the service was constructed.

Return type

None