EventManagementSystem/include/EventManager/Manager.hpp

300 lines
9.2 KiB
C++

#pragma once
/*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at https://mozilla.org/MPL/2.0/.
*
* Copyright 2021 Dominik Meyer <dmeyer@federationhq.de>
* This file is part of the EventManager distribution hosted at https://gitea.federationhq.de/byterazor/EventManager.git
*/
/** @file */
#include <memory>
#include <atomic>
#include <stdexcept>
#include <string>
#include <mutex>
#include <queue>
#include <thread>
#include <list>
#include <map>
#include <condition_variable>
#include <EventManager/Event.hpp>
namespace EventManager
{
/**
* @brief command types
*/
enum class commandType :uint16_t
{
// command to connect a participant to the manager
CONNECT,
// command to disconnect a participant from the manager
DISCONNECT,
// command to schedule start scheduling a participant
ENABLE_SCHEDULING,
// command to disable scheduling for a participant (not schedule it anymore)
DISABLE_SCHEDULING
}; // commandType
// forward declaration of EventManager::Participant
class Participant;
/**
* @class Manager
*
* If you use the manager it has to be a shared pointer. Otherwise you will
* get a mem error.
*
* To add participants to the manager call class function connect.
* Calling start method will start the manager.
*
* Depending on your concept you can first connect all participants to
* the manager and then start it. Or you can start in first and then
* connect the participants. In the first example all participant will
* be started at the same time (when calling start from the manager.)
* In the second example they will be started when they are connected.
* That means if you have one starting event that all participants need
* to receive you would choose example 1.
*/
class Manager : public std::enable_shared_from_this<Manager>
{
/// the thread the event manager is transmitting events in
std::unique_ptr<std::thread> mainThread_;
/// is the main thread running
std::atomic<bool> isMainThreadRunning_;
/// stop the main thread
std::atomic<bool> stopMainThread_;
/// the thread the event manager is scheduling plugins in
std::unique_ptr<std::thread> schedulingThread_;
/// is the scheduling thread running
std::atomic<bool> isSchedulingThreadRunning_;
/// stop the scheduling thread
std::atomic<bool> stopSchedulingThread_;
/// map holding all the event type and plugin combinations
std::map<std::uint32_t, std::list<std::shared_ptr<EventManager::Participant>>> eventMap_;
/// mutex to protect the eventMap
std::mutex mutexEventMap_;
/// queue for incomng events
std::queue<std::shared_ptr<EventManager::Event>> eventQueue_;
/// mutex to protect the event queue
std::mutex mutexEventQueue_;
/// condition variable to wake of thread on new emit
std::condition_variable newEventInQueue_;
/// list of all plugins requiring scheduling
std::list<std::shared_ptr<EventManager::Participant>> schedulingParticipants_;
/// mutex to protect list schedulingParticipants_
std::mutex mutexSchedulingParticipants_;
/// list of all participants connected
std::list<std::shared_ptr<EventManager::Participant>> participants_;
/// mutex to protect participants_
std::mutex mutexParticipants_;
/// the id for the next participant connecting
std::uint32_t nextParticipantID_;
/// queue for different command requests like e.g. connecting a participant to the manager
std::queue<std::pair<EventManager::commandType,std::shared_ptr<EventManager::Participant>>> commandQueue_;
/// mutex to protect the commandQueue_
std::mutex mutexCommandQueue_;
/*
* all private methods
*/
/**
* @brief the method running in the main thread
*/
void mainProcess_();
/**
* @brief the method running in the scheduling thread
*/
void schedulingProcess_();
/**
* @brief process one event (call all the participants)
*/
void processEvent(const std::shared_ptr<EventManager::Event> event);
/**
* @brief processes the commands in the commandQueue depending on their type
*/
void processCommands_();
/**
* @brief adds the queued participants to the list of connected participants
*
* The connectionQueue_ contains the participants that should be connected to
* the manager. All connected participants are stored in the list participants_.
* This class function adds the queued participants to the list participants_
* and removes them from the queue.
*/
void processConnect_( std::shared_ptr<EventManager::Participant> participant );
/**
* @brief removes the given participant form the list of connected participants
*
* The participants_ list contains the participants that are connected to
* the manager. This class function removes the queued participants from the list
* participants_.
*/
void processDisconnect_( std::shared_ptr<EventManager::Participant> participant );
/**
* @brief processes the command to enable scheduling for the given participant
*
* This class function adds the given participant to the schedulingParticipants_ list
* where the participants are scheduled by calling their schedule class function.
*/
void processEnableScheduling_( std::shared_ptr<EventManager::Participant> participant );
/**
* @brief disables the scheduling of the requested participants
*
* Removes the participants from the schedulingParticipants_ list that
* should not be scheduled anymore.
*/
void processDisableScheduling_( std::shared_ptr<EventManager::Participant> participant );
/**
* @brief start the main thread
*/
void startMain_();
/**
* @brief stop the main thread
*/
void stopMain_();
/**
* @brief start the scheduling thread
*/
void startScheduling_();
/**
* @brief stop the scheduling thread
*/
void stopScheduling_();
public:
/**
* @brief The constructor for the event manager
*
* Just initializes all attributes to their starting values
*/
Manager() : mainThread_(nullptr), isMainThreadRunning_(false),
stopMainThread_(false), schedulingThread_(nullptr),
isSchedulingThreadRunning_(false), stopSchedulingThread_(false),
nextParticipantID_(1){}
~Manager();
/**
* @brief start the event manager
*/
void start();
/**
* @brief stop the event manager
*/
void stop();
/**
* @brief check if the eventmanager is running
*/
bool isRunning();
/**
* @brief emit an event and make sure it is delivered to all subscribed plugins
*
* @param event - the event to emit
*/
void emit(std::shared_ptr<EventManager::Event> event);
/**
* @brief subscribe a plugin for the given event type
*
* @param type - the event type to subscribe to
* @param plugin - shared pointer to the plugin which subscribes
*/
void subscribe(std::uint32_t type, std::shared_ptr<EventManager::Participant> plugin);
/**
* @brief unsubscribe a plugin from the given event type
*
* @param type - the event type to unsubscribe from
* @param plugin - shared pointer to the plugin which unsubscribes
*/
void unsubscribe(std::uint32_t type, std::shared_ptr<EventManager::Participant> plugin);
/**
* @brief unsubscribe a plugin from the all event types
*
* @param plugin - shared pointer to the plugin which unsubscribes
*/
void unsubscribe(std::shared_ptr<EventManager::Participant> plugin);
/**
* @brief check if there are any subscriptions within the event manager
*/
bool empty() const;
/**
* @brief Wait for the EventManager to become empty.
*
* @param timeout - how many milliseconds to wait for EventManager becoming empty
*
* @return true - EventManager is empty
* @return false - EventManager is not empty
*/
bool waitEmpty(std::uint32_t timeoutMS) const;
/**
* @brief schedule the given plugin regularly
*
* @param plugin - the plugin to schedule
*/
void schedule(std::shared_ptr<EventManager::Participant> plugin);
/**
* @brief remove a participant from scheduling
*
* @param participant - the participant to remove
*/
void unschedule(std::shared_ptr<EventManager::Participant> participant);
/**
* @brief method to connect a particpant to the manager
*/
void connect(std::shared_ptr<EventManager::Participant> participant);
/**
* @brief method to disconnect a particpant from the manager
*/
void disconnect(std::shared_ptr<EventManager::Participant> participant);
}; // class Manager
}; //namespace EventManager