iceoryx_posh/popo/listener.hpp

Namespaces

Name
iox
iox::popo

Classes

	Name
class	iox::popo::Listener The Listener is a class which reacts to registered events by executing a corresponding callback concurrently. This is achieved via an encapsulated thread inside this class.

Source code

// Copyright (c) 2021 by Apex.AI Inc. All rights reserved.
//
// 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.
//
// SPDX-License-Identifier: Apache-2.0

#ifndef IOX_POSH_POPO_LISTENER_HPP
#define IOX_POSH_POPO_LISTENER_HPP

#include "iceoryx_posh/internal/popo/building_blocks/condition_listener.hpp"
#include "iceoryx_posh/popo/enum_trigger_type.hpp"
#include "iceoryx_posh/popo/notification_attorney.hpp"
#include "iceoryx_posh/popo/notification_callback.hpp"
#include "iceoryx_posh/popo/trigger_handle.hpp"
#include "iceoryx_utils/cxx/expected.hpp"
#include "iceoryx_utils/cxx/method_callback.hpp"
#include "iceoryx_utils/cxx/type_traits.hpp"
#include "iceoryx_utils/internal/concurrent/loffli.hpp"
#include "iceoryx_utils/internal/concurrent/smart_lock.hpp"

#include <thread>

namespace iox
{
namespace popo
{
enum class ListenerError
{
    INVALID_STATE,
    LISTENER_FULL,
    EVENT_ALREADY_ATTACHED,
    EMPTY_INVALIDATION_CALLBACK
};

class Listener
{
  public:
    Listener() noexcept;
    Listener(const Listener&) = delete;
    Listener(Listener&&) = delete;
    ~Listener();

    Listener& operator=(const Listener&) = delete;
    Listener& operator=(Listener&&) = delete;

    template <typename T,
              typename EventType,
              typename ContextDataType,
              typename = std::enable_if_t<std::is_enum<EventType>::value>>
    cxx::expected<ListenerError> attachEvent(T& eventOrigin,
                                             const EventType eventType,
                                             const NotificationCallback<T, ContextDataType>& eventCallback) noexcept;

    template <typename T, typename ContextDataType>
    cxx::expected<ListenerError> attachEvent(T& eventOrigin,
                                             const NotificationCallback<T, ContextDataType>& eventCallback) noexcept;

    template <typename T, typename EventType, typename = std::enable_if_t<std::is_enum<EventType>::value>>
    void detachEvent(T& eventOrigin, const EventType eventType) noexcept;

    template <typename T>
    void detachEvent(T& eventOrigin) noexcept;

    static constexpr uint64_t capacity() noexcept;

    uint64_t size() const noexcept;

  protected:
    Listener(ConditionVariableData& conditionVariableData) noexcept;

  private:
    class Event_t;

    void threadLoop() noexcept;
    cxx::expected<uint32_t, ListenerError>
    addEvent(void* const origin,
             void* const userType,
             const uint64_t eventType,
             const uint64_t eventTypeHash,
             internal::GenericCallbackRef_t callback,
             internal::TranslationCallbackRef_t translationCallback,
             const cxx::MethodCallback<void, uint64_t> invalidationCallback) noexcept;

    void removeTrigger(const uint64_t index) noexcept;

  private:
    enum class NoEnumUsed : EventEnumIdentifier
    {
        PLACEHOLDER = 0
    };

    class Event_t
    {
      public:
        ~Event_t();

        bool isEqualTo(const void* const origin, const uint64_t eventType, const uint64_t eventTypeHash) const noexcept;
        bool reset() noexcept;
        bool init(const uint64_t eventId,
                  void* const origin,
                  void* const userType,
                  const uint64_t eventType,
                  const uint64_t eventTypeHash,
                  internal::GenericCallbackRef_t callback,
                  internal::TranslationCallbackRef_t translationCallback,
                  const cxx::MethodCallback<void, uint64_t> invalidationCallback) noexcept;
        void executeCallback() noexcept;
        bool isInitialized() const noexcept;

      private:
        static constexpr uint64_t INVALID_ID = std::numeric_limits<uint64_t>::max();

        void* m_origin = nullptr;
        uint64_t m_eventType = INVALID_ID;
        uint64_t m_eventTypeHash = INVALID_ID;

        internal::GenericCallbackPtr_t m_callback = nullptr;
        internal::TranslationCallbackPtr_t m_translationCallback = nullptr;
        void* m_userType = nullptr;

        uint64_t m_eventId = INVALID_ID;
        cxx::MethodCallback<void, uint64_t> m_invalidationCallback;
    };

    class IndexManager_t
    {
      public:
        IndexManager_t() noexcept;
        bool pop(uint32_t& index) noexcept;
        void push(const uint32_t index) noexcept;
        uint64_t indicesInUse() const noexcept;

        using LoFFLi = concurrent::LoFFLi;
        LoFFLi::Index_t
            m_loffliStorage[LoFFLi::requiredIndexMemorySize(MAX_NUMBER_OF_EVENTS_PER_LISTENER) / sizeof(uint32_t)];
        LoFFLi m_loffli;
        std::atomic<uint64_t> m_indicesInUse{0U};
    } m_indexManager;


    std::thread m_thread;
    concurrent::smart_lock<Event_t, std::recursive_mutex> m_events[MAX_NUMBER_OF_EVENTS_PER_LISTENER];
    std::mutex m_addEventMutex;

    std::atomic_bool m_wasDtorCalled{false};
    ConditionVariableData* m_conditionVariableData = nullptr;
    ConditionListener m_conditionListener;
};
} // namespace popo
} // namespace iox

#include "iceoryx_posh/internal/popo/listener.inl"

#endif

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Updated on 31 May 2022 at 15:29:16 CEST