DDS.h

/********************************************************************************
 *    Copyright (C) 2017 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH    *
 *                                                                              *
 *              This software is distributed under the terms of the             *
 *              GNU Lesser General Public Licence (LGPL) version 3,             *
 *                  copied verbatim in the file "LICENSE"                       *
 ********************************************************************************/

#ifndef FAIR_MQ_PLUGINS_DDS
#define FAIR_MQ_PLUGINS_DDS

#include <fairmq/Plugin.h>
#include <fairmq/StateQueue.h>
#include <fairmq/Version.h>
#include <fairmq/sdk/commands/Commands.h>

#include <dds/dds.h>

#include <boost/asio/executor.hpp>
#include <boost/asio/executor_work_guard.hpp>
#include <boost/asio/io_context.hpp>

#include <cassert>
#include <chrono>
#include <condition_variable>
#include <mutex>
#include <string>
#include <atomic>
#include <thread>
#include <map>
#include <unordered_map>
#include <utility> // pair
#include <vector>

namespace fair
{
namespace mq
{
namespace plugins
{

struct DDSConfig
{
    // container of sub channel addresses
    unsigned int fNumSubChannels;
    // dds values for the channel
    std::map<uint64_t, std::string> fDDSValues;
};

struct DDSSubscription
{
    DDSSubscription()
        : fDDSCustomCmd(fService)
        , fDDSKeyValue(fService)
    {
        LOG(debug) << "$DDS_TASK_PATH: " << dds::env_prop<dds::task_path>();
        LOG(debug) << "$DDS_GROUP_NAME: " << dds::env_prop<dds::group_name>();
        LOG(debug) << "$DDS_COLLECTION_NAME: " << dds::env_prop<dds::collection_name>();
        LOG(debug) << "$DDS_TASK_NAME: " << dds::env_prop<dds::task_name>();
        LOG(debug) << "$DDS_TASK_INDEX: " << dds::env_prop<dds::task_index>();
        LOG(debug) << "$DDS_COLLECTION_INDEX: " << dds::env_prop<dds::collection_index>();
        LOG(debug) << "$DDS_TASK_ID: " << dds::env_prop<dds::task_id>();
        LOG(debug) << "$DDS_LOCATION: " << dds::env_prop<dds::dds_location>();
        std::string dds_session_id(dds::env_prop<dds::dds_session_id>());
        LOG(debug) << "$DDS_SESSION_ID: " << dds_session_id;

        // subscribe for DDS service errors.
        fService.subscribeOnError([](const dds::intercom_api::EErrorCode errorCode, const std::string& errorMsg) {
            LOG(error) << "DDS Error received: error code: " << errorCode << ", error message: " << errorMsg;
        });

        // fDDSCustomCmd.subscribe([](const std::string& cmd, const std::string& cond, uint64_t senderId) {
            // LOG(debug) << "cmd: " << cmd << ", cond: " << cond << ", senderId: " << senderId;
        // });
        assert(!dds_session_id.empty());
    }

    auto Start() -> void {
        fService.start(dds::env_prop<dds::dds_session_id>());
    }

    ~DDSSubscription() {
        fDDSKeyValue.unsubscribe();
        fDDSCustomCmd.unsubscribe();
    }

    template<typename... Args>
    auto SubscribeCustomCmd(Args&&... args) -> void
    {
        fDDSCustomCmd.subscribe(std::forward<Args>(args)...);
    }

    template<typename... Args>
    auto SubscribeKeyValue(Args&&... args) -> void
    {
        fDDSKeyValue.subscribe(std::forward<Args>(args)...);
    }

    template<typename... Args>
    auto Send(Args&&... args) -> void
    {
        fDDSCustomCmd.send(std::forward<Args>(args)...);
    }

    template<typename... Args>
    auto PutValue(Args&&... args) -> void
    {
        fDDSKeyValue.putValue(std::forward<Args>(args)...);
    }

  private:
    dds::intercom_api::CIntercomService fService;
    dds::intercom_api::CCustomCmd fDDSCustomCmd;
    dds::intercom_api::CKeyValue fDDSKeyValue;
};

struct IofN
{
    IofN(int i, int n)
        : fI(i)
        , fN(n)
    {}

    unsigned int fI;
    unsigned int fN;
    std::vector<std::string> fEntries;
};

class DDS : public Plugin
{
  public:
    DDS(const std::string& name, const Plugin::Version version, const std::string& maintainer, const std::string& homepage, PluginServices* pluginServices);

    ~DDS();

  private:
    auto WaitForExitingAck() -> void;
    auto StartWorkerThread() -> void;

    auto FillChannelContainers() -> void;
    auto EmptyChannelContainers() -> void;

    auto SubscribeForConnectingChannels() -> void;
    auto PublishBoundChannels() -> void;
    auto SubscribeForCustomCommands() -> void;
    auto HandleCmd(const std::string& id, sdk::cmd::Cmd& cmd, const std::string& cond, uint64_t senderId) -> void;

    DDSSubscription fDDS;
    size_t fDDSTaskId;

    std::unordered_map<std::string, std::vector<std::string>> fBindingChans;
    std::unordered_map<std::string, DDSConfig> fConnectingChans;

    std::unordered_map<std::string, int> fI;
    std::unordered_map<std::string, IofN> fIofN;

    std::thread fControllerThread;
    DeviceState fCurrentState, fLastState;

    std::atomic<bool> fDeviceTerminationRequested;

    std::unordered_map<uint64_t, std::pair<std::chrono::steady_clock::time_point, int64_t>> fStateChangeSubscribers;
    uint64_t fLastExternalController;
    bool fExitingAckedByLastExternalController;
    std::condition_variable fExitingAcked;
    std::mutex fStateChangeSubscriberMutex;

    bool fUpdatesAllowed;
    std::mutex fUpdateMutex;
    std::condition_variable fUpdateCondition;

    std::thread fWorkerThread;
    boost::asio::io_context fWorkerQueue;
    boost::asio::executor_work_guard<boost::asio::executor> fWorkGuard;
};

Plugin::ProgOptions DDSProgramOptions()
{
    boost::program_options::options_description options{"DDS Plugin"};
    options.add_options()
        ("dds-i", boost::program_options::value<std::vector<std::string>>()->multitoken()->composing(), "Task index for chosing connection target (single channel n to m). When all values come via same update.")
        ("dds-i-n", boost::program_options::value<std::vector<std::string>>()->multitoken()->composing(), "Task index for chosing connection target (one out of n values to take). When values come as independent updates.")
        ("wait-for-exiting-ack-timeout", boost::program_options::value<unsigned int>()->default_value(1000), "Wait timeout for EXITING state-change acknowledgement by external controller in milliseconds.");

    return options;
}

REGISTER_FAIRMQ_PLUGIN(
    DDS,                                         // Class name
    dds,                                         // Plugin name (string, lower case chars only)
    (Plugin::Version{FAIRMQ_VERSION_MAJOR,
                     FAIRMQ_VERSION_MINOR,
                     FAIRMQ_VERSION_PATCH}),     // Version
    "FairRootGroup <fairroot@gsi.de>",           // Maintainer
    "https://github.com/FairRootGroup/FairMQ",   // Homepage
    DDSProgramOptions                            // custom program options for the plugin
)

} /* namespace plugins */
} /* namespace mq */
} /* namespace fair */

#endif /* FAIR_MQ_PLUGINS_DDS */