Function rcl_client_set_on_new_response_callback

• Defined in File client.h

Function Documentation

rcl_ret_t rcl_client_set_on_new_response_callback(const rcl_client_t *client, rcl_event_callback_t callback, const void *user_data)

Set the on new response callback function for the client.

This API sets the callback function to be called whenever the client is notified about a new response.

Since this callback is called from the middleware, you should aim to make it fast and not blocking. This callback is intended to implement an event driven executor and not process data directly.

See also

rmw_client_set_on_new_response_callback for details about this function.

Doing work in this callback can cause delays, deadlocks, or latency due to cross thread waiting as this process runs on middleware managed threads and is meant only to notify the executor that new data is available in the middleware queue.

Attribute	Adherence
Allocates Memory	No
Thread-Safe	Yes
Uses Atomics	Maybe [1]
Lock-Free	Maybe [1]

[1] rmw implementation defined

Parameters:

• client – [in] The client on which to set the callback

• callback – [in] The callback to be called when new responses arrive, may be NULL

• user_data – [in] Given to the callback when called later, may be NULL

Returns:

RCL_RET_OK if callback was set to the listener, or

Returns:

RCL_RET_INVALID_ARGUMENT if client is NULL, or

Returns:

RCL_RET_UNSUPPORTED if the API is not supported by the middleware