rclcpp/rclcpp_action/include/rclcpp_action/server.hpp
2018-12-06 16:42:25 -08:00

487 lines
16 KiB
C++

// Copyright 2018 Open Source Robotics Foundation, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef RCLCPP_ACTION__SERVER_HPP_
#define RCLCPP_ACTION__SERVER_HPP_
#include <rcl_action/action_server.h>
#include <rosidl_generator_c/action_type_support_struct.h>
#include <rosidl_typesupport_cpp/action_type_support.hpp>
#include <rclcpp/node_interfaces/node_base_interface.hpp>
#include <rclcpp/node_interfaces/node_clock_interface.hpp>
#include <rclcpp/node_interfaces/node_logging_interface.hpp>
#include <rclcpp/waitable.hpp>
#include <functional>
#include <memory>
#include <mutex>
#include <string>
#include <unordered_map>
#include <utility>
#include "rclcpp_action/visibility_control.hpp"
#include "rclcpp_action/server_goal_handle.hpp"
#include "rclcpp_action/types.hpp"
namespace rclcpp_action
{
// Forward declaration
class ServerBaseImpl;
/// A response returned by an action server callback when a goal is requested.
enum class GoalResponse : int8_t
{
/// The goal is rejected and will not be executed.
REJECT = 1,
/// The server accepts the goal, and is going to begin execution immediately.
ACCEPT_AND_EXECUTE = 2,
/// The server accepts the goal, and is going to execute it later.
ACCEPT_AND_DEFER = 3,
};
/// A response returned by an action server callback when a goal has been asked to be canceled.
enum class CancelResponse : int8_t
{
/// The server will not try to cancel the goal.
REJECT = 1,
/// The server has agreed to try to cancel the goal.
ACCEPT = 2,
};
/// Base Action Server implementation
/// \internal
/**
* This class should not be used directly by users writing an action server.
* Instead users should use `rclcpp_action::Server<>`.
*
* Internally, this class is responsible for interfacing with the `rcl_action` API.
*/
class ServerBase : public rclcpp::Waitable
{
public:
RCLCPP_ACTION_PUBLIC
virtual ~ServerBase();
// -------------
// Waitables API
/// Return the number of subscriptions used to implement an action server
/// \internal
RCLCPP_ACTION_PUBLIC
size_t
get_number_of_ready_subscriptions() override;
/// Return the number of timers used to implement an action server
/// \internal
RCLCPP_ACTION_PUBLIC
size_t
get_number_of_ready_timers() override;
/// Return the number of service clients used to implement an action server
/// \internal
RCLCPP_ACTION_PUBLIC
size_t
get_number_of_ready_clients() override;
/// Return the number of service servers used to implement an action server
/// \internal
RCLCPP_ACTION_PUBLIC
size_t
get_number_of_ready_services() override;
/// Return the number of guard conditions used to implement an action server
/// \internal
RCLCPP_ACTION_PUBLIC
size_t
get_number_of_ready_guard_conditions() override;
/// Add all entities to a wait set.
/// \internal
RCLCPP_ACTION_PUBLIC
bool
add_to_wait_set(rcl_wait_set_t * wait_set) override;
/// Return true if any entity belonging to the action server is ready to be executed.
/// \internal
RCLCPP_ACTION_PUBLIC
bool
is_ready(rcl_wait_set_t *) override;
/// Act on entities in the wait set which are ready to be acted upon.
/// \internal
RCLCPP_ACTION_PUBLIC
void
execute() override;
// End Waitables API
// -----------------
protected:
RCLCPP_ACTION_PUBLIC
ServerBase(
rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_base,
rclcpp::node_interfaces::NodeClockInterface::SharedPtr node_clock,
rclcpp::node_interfaces::NodeLoggingInterface::SharedPtr node_logging,
const std::string & name,
const rosidl_action_type_support_t * type_support,
const rcl_action_server_options_t & options);
// -----------------------------------------------------
// API for communication between ServerBase and Server<>
// ServerBase will call this function when a goal request is received.
// The subclass should convert to the real type and call a user's callback.
/// \internal
RCLCPP_ACTION_PUBLIC
virtual
std::pair<GoalResponse, std::shared_ptr<void>>
call_handle_goal_callback(GoalID &, std::shared_ptr<void> request) = 0;
// ServerBase will determine which goal ids are being cancelled, and then call this function for
// each goal id.
// The subclass should look up a goal handle and call the user's callback.
/// \internal
RCLCPP_ACTION_PUBLIC
virtual
CancelResponse
call_handle_cancel_callback(const GoalID & uuid) = 0;
/// Given a goal request message, return the UUID contained within.
/// \internal
RCLCPP_ACTION_PUBLIC
virtual
GoalID
get_goal_id_from_goal_request(void * message) = 0;
/// Create an empty goal request message so it can be taken from a lower layer.
/// \internal
RCLCPP_ACTION_PUBLIC
virtual
std::shared_ptr<void>
create_goal_request() = 0;
/// Call user callback to inform them a goal has been accepted.
/// \internal
RCLCPP_ACTION_PUBLIC
virtual
void
call_goal_accepted_callback(
std::shared_ptr<rcl_action_goal_handle_t> rcl_goal_handle,
GoalID uuid, std::shared_ptr<void> goal_request_message) = 0;
/// Given a result request message, return the UUID contained within.
/// \internal
RCLCPP_ACTION_PUBLIC
virtual
GoalID
get_goal_id_from_result_request(void * message) = 0;
/// Create an empty goal request message so it can be taken from a lower layer.
/// \internal
RCLCPP_ACTION_PUBLIC
virtual
std::shared_ptr<void>
create_result_request() = 0;
/// Create an empty goal result message so it can be sent as a reply in a lower layer
/// \internal
RCLCPP_ACTION_PUBLIC
virtual
std::shared_ptr<void>
create_result_response(decltype(action_msgs::msg::GoalStatus::status) status) = 0;
/// \internal
RCLCPP_ACTION_PUBLIC
void
publish_status();
/// \internal
RCLCPP_ACTION_PUBLIC
void
notify_goal_terminal_state();
/// \internal
RCLCPP_ACTION_PUBLIC
void
publish_result(const GoalID & uuid, std::shared_ptr<void> result_msg);
/// \internal
RCLCPP_ACTION_PUBLIC
void
publish_feedback(std::shared_ptr<void> feedback_msg);
// End API for communication between ServerBase and Server<>
// ---------------------------------------------------------
private:
/// Handle a request to add a new goal to the server
/// \internal
RCLCPP_ACTION_PUBLIC
void
execute_goal_request_received();
/// Handle a request to cancel goals on the server
/// \internal
RCLCPP_ACTION_PUBLIC
void
execute_cancel_request_received();
/// Handle a request to get the result of an action
/// \internal
RCLCPP_ACTION_PUBLIC
void
execute_result_request_received();
/// Handle a timeout indicating a completed goal should be forgotten by the server
/// \internal
RCLCPP_ACTION_PUBLIC
void
execute_check_expired_goals();
/// Private implementation
/// \internal
std::unique_ptr<ServerBaseImpl> pimpl_;
};
/// Action Server
/**
* This class creates an action server.
*
* Create an instance of this server using `rclcpp_action::create_server()`.
*
* Internally, this class is responsible for:
* - coverting between the C++ action type and generic types for `rclcpp_action::ServerBase`, and
* - calling user callbacks.
*/
template<typename ActionT>
class Server : public ServerBase, public std::enable_shared_from_this<Server<ActionT>>
{
public:
RCLCPP_SMART_PTR_DEFINITIONS_NOT_COPYABLE(Server)
/// Signature of a callback that accepts or rejects goal requests.
using GoalCallback = std::function<GoalResponse(
const GoalID &, std::shared_ptr<const typename ActionT::Goal>)>;
/// Signature of a callback that accepts or rejects requests to cancel a goal.
using CancelCallback = std::function<CancelResponse(std::shared_ptr<ServerGoalHandle<ActionT>>)>;
/// Signature of a callback that is used to notify when the goal has been accepted.
using AcceptedCallback = std::function<void (std::shared_ptr<ServerGoalHandle<ActionT>>)>;
/// Construct an action server.
/**
* This constructs an action server, but it will not work until it has been added to a node.
* Use `rclcpp_action::create_server()` to both construct and add to a node.
*
* Three callbacks must be provided:
* - one to accept or reject goals sent to the server,
* - one to accept or reject requests to cancel a goal,
* - one to receive a goal handle after a goal has been accepted.
* All callbacks must be non-blocking.
* The result of a goal should be set using methods on `rclcpp_action::ServerGoalHandle<>`.
*
* \param[in] node_base a pointer to the base interface of a node.
* \param[in] node_clock a pointer to an interface that allows getting a node's clock.
* \param[in] node_logging a pointer to an interface that allows getting a node's logger.
* \param[in] name the name of an action.
* The same name and type must be used by both the action client and action server to
* communicate.
* \param[in] options options to pass to the underlying `rcl_action_server_t`.
* \param[in] handle_goal a callback that decides if a goal should be accepted or rejected.
* \param[in] handle_cancel a callback that decides if a goal should be attemted to be canceled.
* The return from this callback only indicates if the server will try to cancel a goal.
* It does not indicate if the goal was actually canceled.
* \param[in] handle_accepted a callback that is called to give the user a handle to the goal.
* execution.
*/
Server(
rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_base,
rclcpp::node_interfaces::NodeClockInterface::SharedPtr node_clock,
rclcpp::node_interfaces::NodeLoggingInterface::SharedPtr node_logging,
const std::string & name,
const rcl_action_server_options_t & options,
GoalCallback handle_goal,
CancelCallback handle_cancel,
AcceptedCallback handle_accepted
)
: ServerBase(
node_base,
node_clock,
node_logging,
name,
rosidl_typesupport_cpp::get_action_type_support_handle<ActionT>(),
options),
handle_goal_(handle_goal),
handle_cancel_(handle_cancel),
handle_accepted_(handle_accepted)
{
}
virtual ~Server() = default;
protected:
// -----------------------------------------------------
// API for communication between ServerBase and Server<>
/// \internal
std::pair<GoalResponse, std::shared_ptr<void>>
call_handle_goal_callback(GoalID & uuid, std::shared_ptr<void> message) override
{
// TODO(sloretz) update and remove assert when IDL pipeline allows nesting user's type
static_assert(
std::is_same<typename ActionT::Goal, typename ActionT::GoalRequestService::Request>::value,
"Assuming user fields were merged with goal request fields");
GoalResponse user_response = handle_goal_(
uuid, std::static_pointer_cast<typename ActionT::Goal>(message));
auto ros_response = std::make_shared<typename ActionT::GoalRequestService::Response>();
ros_response->accepted = GoalResponse::ACCEPT_AND_EXECUTE == user_response ||
GoalResponse::ACCEPT_AND_DEFER == user_response;
return std::make_pair(user_response, ros_response);
}
/// \internal
CancelResponse
call_handle_cancel_callback(const GoalID & uuid) override
{
std::lock_guard<std::mutex> lock(goal_handles_mutex_);
CancelResponse resp = CancelResponse::REJECT;
auto element = goal_handles_.find(uuid);
if (element != goal_handles_.end()) {
std::shared_ptr<ServerGoalHandle<ActionT>> goal_handle = element->second.lock();
if (goal_handle) {
resp = handle_cancel_(goal_handle);
if (CancelResponse::ACCEPT == resp) {
goal_handle->_set_canceling();
}
}
}
return resp;
}
/// \internal
void
call_goal_accepted_callback(
std::shared_ptr<rcl_action_goal_handle_t> rcl_goal_handle,
GoalID uuid, std::shared_ptr<void> goal_request_message) override
{
std::shared_ptr<ServerGoalHandle<ActionT>> goal_handle;
std::weak_ptr<Server<ActionT>> weak_this = this->shared_from_this();
std::function<void(const GoalID &, std::shared_ptr<void>)> on_terminal_state =
[weak_this](const GoalID & uuid, std::shared_ptr<void> result_message)
{
std::shared_ptr<Server<ActionT>> shared_this = weak_this.lock();
if (!shared_this) {
return;
}
// Send result message to anyone that asked
shared_this->publish_result(uuid, result_message);
// Publish a status message any time a goal handle changes state
shared_this->publish_status();
// notify base so it can recalculate the expired goal timer
shared_this->notify_goal_terminal_state();
// Delete data now (ServerBase and rcl_action_server_t keep data until goal handle expires)
std::lock_guard<std::mutex> lock(shared_this->goal_handles_mutex_);
shared_this->goal_handles_.erase(uuid);
};
std::function<void(const GoalID &)> on_executing =
[weak_this](const GoalID & uuid)
{
std::shared_ptr<Server<ActionT>> shared_this = weak_this.lock();
if (!shared_this) {
return;
}
(void)uuid;
// Publish a status message any time a goal handle changes state
shared_this->publish_status();
};
std::function<void(std::shared_ptr<typename ActionT::Feedback>)> publish_feedback =
[weak_this](std::shared_ptr<typename ActionT::Feedback> feedback_msg)
{
std::shared_ptr<Server<ActionT>> shared_this = weak_this.lock();
if (!shared_this) {
return;
}
shared_this->publish_feedback(std::static_pointer_cast<void>(feedback_msg));
};
goal_handle.reset(
new ServerGoalHandle<ActionT>(
rcl_goal_handle, uuid,
std::static_pointer_cast<const typename ActionT::Goal>(goal_request_message),
on_terminal_state, on_executing, publish_feedback));
{
std::lock_guard<std::mutex> lock(goal_handles_mutex_);
goal_handles_[uuid] = goal_handle;
}
handle_accepted_(goal_handle);
}
/// \internal
GoalID
get_goal_id_from_goal_request(void * message) override
{
return
static_cast<typename ActionT::GoalRequestService::Request *>(message)->action_goal_id.uuid;
}
/// \internal
std::shared_ptr<void>
create_goal_request() override
{
return std::shared_ptr<void>(new typename ActionT::GoalRequestService::Request());
}
/// \internal
GoalID
get_goal_id_from_result_request(void * message) override
{
return
static_cast<typename ActionT::GoalResultService::Request *>(message)->action_goal_id.uuid;
}
/// \internal
std::shared_ptr<void>
create_result_request() override
{
return std::shared_ptr<void>(new typename ActionT::GoalResultService::Request());
}
/// \internal
std::shared_ptr<void>
create_result_response(decltype(action_msgs::msg::GoalStatus::status) status) override
{
auto result = std::make_shared<typename ActionT::GoalResultService::Response>();
result->action_status = status;
return std::static_pointer_cast<void>(result);
}
// End API for communication between ServerBase and Server<>
// ---------------------------------------------------------
private:
GoalCallback handle_goal_;
CancelCallback handle_cancel_;
AcceptedCallback handle_accepted_;
using GoalHandleWeakPtr = std::weak_ptr<ServerGoalHandle<ActionT>>;
/// A map of goal id to goal handle weak pointers.
/// This is used to provide a goal handle to handle_cancel.
std::unordered_map<GoalID, GoalHandleWeakPtr> goal_handles_;
std::mutex goal_handles_mutex_;
};
} // namespace rclcpp_action
#endif // RCLCPP_ACTION__SERVER_HPP_