subscription.hpp

Go to the documentation of this file.

// Copyright 2014 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__SUBSCRIPTION_HPP_
#define RCLCPP__SUBSCRIPTION_HPP_
 
#include <rmw/error_handling.h>
#include <rmw/rmw.h>
 
#include <chrono>
#include <functional>
#include <iostream>
#include <memory>
#include <sstream>
#include <string>
#include <utility>
 
#include "rcl/error_handling.h"
#include "rcl/subscription.h"
 
#include "rclcpp/any_subscription_callback.hpp"
#include "rclcpp/detail/resolve_use_intra_process.hpp"
#include "rclcpp/detail/resolve_intra_process_buffer_type.hpp"
#include "rclcpp/exceptions.hpp"
#include "rclcpp/expand_topic_or_service_name.hpp"
#include "rclcpp/experimental/intra_process_manager.hpp"
#include "rclcpp/experimental/subscription_intra_process.hpp"
#include "rclcpp/logging.hpp"
#include "rclcpp/macros.hpp"
#include "rclcpp/message_info.hpp"
#include "rclcpp/message_memory_strategy.hpp"
#include "rclcpp/node_interfaces/node_base_interface.hpp"
#include "rclcpp/subscription_base.hpp"
#include "rclcpp/subscription_options.hpp"
#include "rclcpp/subscription_traits.hpp"
#include "rclcpp/type_support_decl.hpp"
#include "rclcpp/visibility_control.hpp"
#include "rclcpp/waitable.hpp"
#include "rclcpp/topic_statistics/subscription_topic_statistics.hpp"
#include "tracetools/tracetools.h"
 
namespace rclcpp
{
 
namespace node_interfaces
{
class NodeTopicsInterface;
}  // namespace node_interfaces
 
template<
  typename CallbackMessageT,
  typename AllocatorT = std::allocator<void>,
  typename MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<
    CallbackMessageT,
    AllocatorT
  >>
class Subscription : public SubscriptionBase
{
  friend class rclcpp::node_interfaces::NodeTopicsInterface;
 
public:
  using MessageAllocatorTraits = allocator::AllocRebind<CallbackMessageT, AllocatorT>;
  using MessageAllocator = typename MessageAllocatorTraits::allocator_type;
  using MessageDeleter = allocator::Deleter<MessageAllocator, CallbackMessageT>;
  using ConstMessageSharedPtr = std::shared_ptr<const CallbackMessageT>;
  using MessageUniquePtr = std::unique_ptr<CallbackMessageT, MessageDeleter>;
  using SubscriptionTopicStatisticsSharedPtr =
    std::shared_ptr<rclcpp::topic_statistics::SubscriptionTopicStatistics<CallbackMessageT>>;
 
  RCLCPP_SMART_PTR_DEFINITIONS(Subscription)
 
  
 
  Subscription(
    rclcpp::node_interfaces::NodeBaseInterface * node_base,
    const rosidl_message_type_support_t & type_support_handle,
    const std::string & topic_name,
    const rclcpp::QoS & qos,
    AnySubscriptionCallback<CallbackMessageT, AllocatorT> callback,
    const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT> & options,
    typename MessageMemoryStrategyT::SharedPtr message_memory_strategy,
    SubscriptionTopicStatisticsSharedPtr subscription_topic_statistics = nullptr)
  : SubscriptionBase(
      node_base,
      type_support_handle,
      topic_name,
      options.template to_rcl_subscription_options<CallbackMessageT>(qos),
      rclcpp::subscription_traits::is_serialized_subscription_argument<CallbackMessageT>::value),
    any_callback_(callback),
    options_(options),
    message_memory_strategy_(message_memory_strategy)
  {
    if (options.event_callbacks.deadline_callback) {
      this->add_event_handler(
        options.event_callbacks.deadline_callback,
        RCL_SUBSCRIPTION_REQUESTED_DEADLINE_MISSED);
    }
    if (options.event_callbacks.liveliness_callback) {
      this->add_event_handler(
        options.event_callbacks.liveliness_callback,
        RCL_SUBSCRIPTION_LIVELINESS_CHANGED);
    }
    if (options.event_callbacks.incompatible_qos_callback) {
      this->add_event_handler(
        options.event_callbacks.incompatible_qos_callback,
        RCL_SUBSCRIPTION_REQUESTED_INCOMPATIBLE_QOS);
    } else if (options_.use_default_callbacks) {
      // Register default callback when not specified
      try {
        this->add_event_handler(
          [this](QOSRequestedIncompatibleQoSInfo & info) {
            this->default_incompatible_qos_callback(info);
          },
          RCL_SUBSCRIPTION_REQUESTED_INCOMPATIBLE_QOS);
      } catch (UnsupportedEventTypeException & /*exc*/) {
        // pass
      }
    }
 
    // Setup intra process publishing if requested.
    if (rclcpp::detail::resolve_use_intra_process(options, *node_base)) {
      using rclcpp::detail::resolve_intra_process_buffer_type;
 
      // Check if the QoS is compatible with intra-process.
      rmw_qos_profile_t qos_profile = get_actual_qos().get_rmw_qos_profile();
      if (qos_profile.history == RMW_QOS_POLICY_HISTORY_KEEP_ALL) {
        throw std::invalid_argument(
                "intraprocess communication is not allowed with keep all history qos policy");
      }
      if (qos_profile.depth == 0) {
        throw std::invalid_argument(
                "intraprocess communication is not allowed with 0 depth qos policy");
      }
      if (qos_profile.durability != RMW_QOS_POLICY_DURABILITY_VOLATILE) {
        throw std::invalid_argument(
                "intraprocess communication allowed only with volatile durability");
      }
 
      // First create a SubscriptionIntraProcess which will be given to the intra-process manager.
      auto context = node_base->get_context();
      using SubscriptionIntraProcessT = rclcpp::experimental::SubscriptionIntraProcess<
        CallbackMessageT,
        AllocatorT,
        typename MessageUniquePtr::deleter_type>;
      auto subscription_intra_process = std::make_shared<SubscriptionIntraProcessT>(
        callback,
        options.get_allocator(),
        context,
        this->get_topic_name(),  // important to get like this, as it has the fully-qualified name
        qos_profile,
        resolve_intra_process_buffer_type(options.intra_process_buffer_type, callback));
      TRACEPOINT(
        rclcpp_subscription_init,
        (const void *)get_subscription_handle().get(),
        (const void *)subscription_intra_process.get());
 
      // Add it to the intra process manager.
      using rclcpp::experimental::IntraProcessManager;
      auto ipm = context->get_sub_context<IntraProcessManager>();
      uint64_t intra_process_subscription_id = ipm->add_subscription(subscription_intra_process);
      this->setup_intra_process(intra_process_subscription_id, ipm);
    }
 
    if (subscription_topic_statistics != nullptr) {
      this->subscription_topic_statistics_ = std::move(subscription_topic_statistics);
    }
 
    TRACEPOINT(
      rclcpp_subscription_init,
      (const void *)get_subscription_handle().get(),
      (const void *)this);
    TRACEPOINT(
      rclcpp_subscription_callback_added,
      (const void *)this,
      (const void *)&any_callback_);
    // The callback object gets copied, so if registration is done too early/before this point
    // (e.g. in `AnySubscriptionCallback::set()`), its address won't match any address used later
    // in subsequent tracepoints.
#ifndef TRACETOOLS_DISABLED
    any_callback_.register_callback_for_tracing();
#endif
  }
 
  void
  post_init_setup(
    rclcpp::node_interfaces::NodeBaseInterface * node_base,
    const rclcpp::QoS & qos,
    const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT> & options)
  {
    (void)node_base;
    (void)qos;
    (void)options;
  }
 
 
  bool
  take(CallbackMessageT & message_out, rclcpp::MessageInfo & message_info_out)
  {
    return this->take_type_erased(static_cast<void *>(&message_out), message_info_out);
  }
 
  std::shared_ptr<void>
  create_message() override
  {
    /* The default message memory strategy provides a dynamically allocated message on each call to
     * create_message, though alternative memory strategies that re-use a preallocated message may be
     * used (see rclcpp/strategies/message_pool_memory_strategy.hpp).
     */
    return message_memory_strategy_->borrow_message();
  }
 
  std::shared_ptr<rclcpp::SerializedMessage>
  create_serialized_message() override
  {
    return message_memory_strategy_->borrow_serialized_message();
  }
 
  void
  handle_message(
    std::shared_ptr<void> & message,
    const rclcpp::MessageInfo & message_info) override
  {
    if (matches_any_intra_process_publishers(&message_info.get_rmw_message_info().publisher_gid)) {
      // In this case, the message will be delivered via intra process and
      // we should ignore this copy of the message.
      return;
    }
    auto typed_message = std::static_pointer_cast<CallbackMessageT>(message);
    any_callback_.dispatch(typed_message, message_info);
 
    if (subscription_topic_statistics_) {
      const auto nanos = std::chrono::time_point_cast<std::chrono::nanoseconds>(
        std::chrono::system_clock::now());
      const auto time = rclcpp::Time(nanos.time_since_epoch().count());
      subscription_topic_statistics_->handle_message(*typed_message, time);
    }
  }
 
  void
  handle_loaned_message(
    void * loaned_message,
    const rclcpp::MessageInfo & message_info) override
  {
    auto typed_message = static_cast<CallbackMessageT *>(loaned_message);
    // message is loaned, so we have to make sure that the deleter does not deallocate the message
    auto sptr = std::shared_ptr<CallbackMessageT>(
      typed_message, [](CallbackMessageT * msg) {(void) msg;});
    any_callback_.dispatch(sptr, message_info);
  }
 
 
  void
  return_message(std::shared_ptr<void> & message) override
  {
    auto typed_message = std::static_pointer_cast<CallbackMessageT>(message);
    message_memory_strategy_->return_message(typed_message);
  }
 
 
  void
  return_serialized_message(std::shared_ptr<rclcpp::SerializedMessage> & message) override
  {
    message_memory_strategy_->return_serialized_message(message);
  }
 
  bool
  use_take_shared_method() const
  {
    return any_callback_.use_take_shared_method();
  }
 
private:
  RCLCPP_DISABLE_COPY(Subscription)
 
  AnySubscriptionCallback<CallbackMessageT, AllocatorT> any_callback_;
 
  const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT> options_;
  typename message_memory_strategy::MessageMemoryStrategy<CallbackMessageT, AllocatorT>::SharedPtr
    message_memory_strategy_;
  SubscriptionTopicStatisticsSharedPtr subscription_topic_statistics_{nullptr};
};
 
}  // namespace rclcpp
 
#endif  // RCLCPP__SUBSCRIPTION_HPP_