Class ServiceClientProxyManager

Inheritance Relationships

Base Type

  • public std::enable_shared_from_this< ServiceClientProxyManager >

Class Documentation

class ServiceClientProxyManager : public std::enable_shared_from_this<ServiceClientProxyManager>

Managing all service client proxies.

This class is responsible for managing all created service client proxies. Whenever a real service server is detected to have started, the corresponding service client proxy will be created to connect to this service server.

Public Types

using SharedPtr = std::shared_ptr<ServiceClientProxyManager>
using ClientProxy = rclcpp::GenericClient
using SharedClientProxy = rclcpp::GenericClient::SharedPtr
using ClientProxyChangeCallbackType = std::function<bool(SharedClientProxy&)>

Public Functions

ServiceClientProxyManager(const std::string &base_service_name, const std::string &service_type, rclcpp::Node::SharedPtr &node, ResponseReceiveQueue::SharedPtr &response_queue, std::chrono::seconds discovery_interval = std::chrono::seconds(1))
~ServiceClientProxyManager()
void set_client_proxy_change_callback(ClientProxyChangeCallbackType func_add, ClientProxyChangeCallbackType func_remove)

Set the callback function to be called when a load balancing service is added or removed.

Parameters:

  • func_add – A callback for adding a new load balancing service server

  • func_remove – A callback for removing a load balancing service server

bool async_send_request(SharedClientProxy &client_proxy, rclcpp::GenericService::SharedRequest &request, int64_t &sequence)

Send a request to the load balancing service server using the specified service client proxy.

Parameters:

  • client_proxy – Specified service client proxy

  • request – Untyped request message

  • sequence – Output sequence number of sending request

Returns:

True if sending successfully, otherwise False.

SharedClientProxy create_service_proxy(const std::string service_name)

Create generic client to specified service name.

Parameters:

service_name – service name to be connected by created generic client

Returns:

A shared pointer to GenericClient.

void start_discovery_service_servers_thread()

Start a thread to periodically discover new load balancing service servers.

void stop_discovery_thread_running(void)

Set a flag to terminate discovery service servers thread.

bool is_discovery_thread_running(void)

Check if discovery service servers thread is launched.

void remove_load_balancing_service(const std::string &new_services)

Remove a record of service server name and its corresponding service client proxy. These records are maintained by the ServiceClientProxyManager itself.

Parameters:

new_services – load balancing service name to be removed.

void send_request_to_check_service_servers()

Activate a discovery operation once in the discovery thread.

SharedClientProxy get_created_client_proxy(const std::string &service_name)

Return the corresponding service client proxy based on the load balancing service name.

Parameters:

service_name – load balancing service name

Returns:

service client proxy if found, otherwise nullptr