Reactor.cc

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#include "Reactor.hh"
#include "CommandLineParser.hh"
#include "RTScheduler.hh"
#include "EventDistributor.hh"
#include "GlobalCommandController.hh"
#include "InputEventGenerator.hh"
#include "InputEvents.hh"
#include "DiskFactory.hh"
#include "DiskManipulator.hh"
#include "DiskChanger.hh"
#include "FilePool.hh"
#include "UserSettings.hh"
#include "RomDatabase.hh"
#include "TclCallbackMessages.hh"
#include "MSXMotherBoard.hh"
#include "StateChangeDistributor.hh"
#include "Command.hh"
#include "AfterCommand.hh"
#include "MessageCommand.hh"
#include "CommandException.hh"
#include "GlobalCliComm.hh"
#include "InfoTopic.hh"
#include "Display.hh"
#include "Mixer.hh"
#include "AviRecorder.hh"
#include "GlobalSettings.hh"
#include "BooleanSetting.hh"
#include "EnumSetting.hh"
#include "TclObject.hh"
#include "HardwareConfig.hh"
#include "XMLElement.hh"
#include "XMLException.hh"
#include "FileContext.hh"
#include "FileException.hh"
#include "FileOperations.hh"
#include "ReadDir.hh"
#include "Thread.hh"
#include "Timer.hh"
#include "serialize.hh"
#include "openmsx.hh"
#include "checked_cast.hh"
#include "statp.hh"
#include "stl.hh"
#include "unreachable.hh"
#include "memory.hh"
#include "build-info.hh"
#include <cassert>

using std::string;
using std::vector;
using std::make_shared;

namespace openmsx {

class QuitCommand final : public Command
{
public:
        QuitCommand(CommandController& commandController, EventDistributor& distributor);
        void execute(array_ref<TclObject> tokens, TclObject& result) override;
        string help(const vector<string>& tokens) const override;
private:
        EventDistributor& distributor;
};

class MachineCommand final : public Command
{
public:
        MachineCommand(CommandController& commandController, Reactor& reactor);
        void execute(array_ref<TclObject> tokens, TclObject& result) override;
        string help(const vector<string>& tokens) const override;
        void tabCompletion(vector<string>& tokens) const override;
private:
        Reactor& reactor;
};

class TestMachineCommand final : public Command
{
public:
        TestMachineCommand(CommandController& commandController, Reactor& reactor);
        void execute(array_ref<TclObject> tokens, TclObject& result) override;
        string help(const vector<string>& tokens) const override;
        void tabCompletion(vector<string>& tokens) const override;
private:
        Reactor& reactor;
};

class CreateMachineCommand final : public Command
{
public:
        CreateMachineCommand(CommandController& commandController, Reactor& reactor);
        void execute(array_ref<TclObject> tokens, TclObject& result) override;
        string help(const vector<string>& tokens) const override;
private:
        Reactor& reactor;
};

class DeleteMachineCommand final : public Command
{
public:
        DeleteMachineCommand(CommandController& commandController, Reactor& reactor);
        void execute(array_ref<TclObject> tokens, TclObject& result) override;
        string help(const vector<string>& tokens) const override;
        void tabCompletion(vector<string>& tokens) const override;
private:
        Reactor& reactor;
};

class ListMachinesCommand final : public Command
{
public:
        ListMachinesCommand(CommandController& commandController, Reactor& reactor);
        void execute(array_ref<TclObject> tokens, TclObject& result) override;
        string help(const vector<string>& tokens) const override;
private:
        Reactor& reactor;
};

class ActivateMachineCommand final : public Command
{
public:
        ActivateMachineCommand(CommandController& commandController, Reactor& reactor);
        void execute(array_ref<TclObject> tokens, TclObject& result) override;
        string help(const vector<string>& tokens) const override;
        void tabCompletion(vector<string>& tokens) const override;
private:
        Reactor& reactor;
};

class StoreMachineCommand final : public Command
{
public:
        StoreMachineCommand(CommandController& commandController, Reactor& reactor);
        void execute(array_ref<TclObject> tokens, TclObject& result) override;
        string help(const vector<string>& tokens) const override;
        void tabCompletion(vector<string>& tokens) const override;
private:
        Reactor& reactor;
};

class RestoreMachineCommand final : public Command
{
public:
        RestoreMachineCommand(CommandController& commandController, Reactor& reactor);
        void execute(array_ref<TclObject> tokens, TclObject& result) override;
        string help(const vector<string>& tokens) const override;
        void tabCompletion(vector<string>& tokens) const override;
private:
        Reactor& reactor;
};

class ConfigInfo final : public InfoTopic
{
public:
        ConfigInfo(InfoCommand& openMSXInfoCommand, const string& configName);
        void execute(array_ref<TclObject> tokens,
                     TclObject& result) const override;
        string help(const vector<string>& tokens) const override;
        void tabCompletion(vector<string>& tokens) const override;
private:
        const string configName;
};

class RealTimeInfo final : public InfoTopic
{
public:
        explicit RealTimeInfo(InfoCommand& openMSXInfoCommand);
        void execute(array_ref<TclObject> tokens,
                     TclObject& result) const override;
        string help(const vector<string>& tokens) const override;
private:
        const uint64_t reference;
};


Reactor::Reactor()
        : activeBoard(nullptr)
        , blockedCounter(0)
        , paused(false)
        , running(true)
        , isInit(false)
{
#if UNIQUE_PTR_BUG
        display = nullptr;
#endif
}

void Reactor::init()
{
        rtScheduler = make_unique<RTScheduler>();
        eventDistributor = make_unique<EventDistributor>(*this);
        globalCliComm = make_unique<GlobalCliComm>();
        globalCommandController = make_unique<GlobalCommandController>(
                *eventDistributor, *globalCliComm, *this);
        globalSettings = make_unique<GlobalSettings>(
                *globalCommandController);
        inputEventGenerator = make_unique<InputEventGenerator>(
                *globalCommandController, *eventDistributor, *globalSettings);
        mixer = make_unique<Mixer>(
                *this, *globalCommandController);
        diskFactory = make_unique<DiskFactory>(
                *this);
        diskManipulator = make_unique<DiskManipulator>(
                *globalCommandController, *this);
        virtualDrive = make_unique<DiskChanger>(
                *this, "virtual_drive");
        filePool = make_unique<FilePool>(*globalCommandController, *this);
        userSettings = make_unique<UserSettings>(
                *globalCommandController);
        afterCommand = make_unique<AfterCommand>(
                *this, *eventDistributor, *globalCommandController);
        quitCommand = make_unique<QuitCommand>(
                *globalCommandController, *eventDistributor);
        messageCommand = make_unique<MessageCommand>(
                *globalCommandController);
        machineCommand = make_unique<MachineCommand>(
                *globalCommandController, *this);
        testMachineCommand = make_unique<TestMachineCommand>(
                *globalCommandController, *this);
        createMachineCommand = make_unique<CreateMachineCommand>(
                *globalCommandController, *this);
        deleteMachineCommand = make_unique<DeleteMachineCommand>(
                *globalCommandController, *this);
        listMachinesCommand = make_unique<ListMachinesCommand>(
                *globalCommandController, *this);
        activateMachineCommand = make_unique<ActivateMachineCommand>(
                *globalCommandController, *this);
        storeMachineCommand = make_unique<StoreMachineCommand>(
                *globalCommandController, *this);
        restoreMachineCommand = make_unique<RestoreMachineCommand>(
                *globalCommandController, *this);
        aviRecordCommand = make_unique<AviRecorder>(*this);
        extensionInfo = make_unique<ConfigInfo>(
                getOpenMSXInfoCommand(), "extensions");
        machineInfo   = make_unique<ConfigInfo>(
                getOpenMSXInfoCommand(), "machines");
        realTimeInfo = make_unique<RealTimeInfo>(
                getOpenMSXInfoCommand());
        tclCallbackMessages = make_unique<TclCallbackMessages>(
                *globalCliComm, *globalCommandController);

        createMachineSetting();

        getGlobalSettings().getPauseSetting().attach(*this);

        eventDistributor->registerEventListener(OPENMSX_QUIT_EVENT, *this);
        eventDistributor->registerEventListener(OPENMSX_FOCUS_EVENT, *this);
        eventDistributor->registerEventListener(OPENMSX_DELETE_BOARDS, *this);
        isInit = true;
}

Reactor::~Reactor()
{
        if (!isInit) return;
        deleteBoard(activeBoard);

        eventDistributor->unregisterEventListener(OPENMSX_QUIT_EVENT, *this);
        eventDistributor->unregisterEventListener(OPENMSX_FOCUS_EVENT, *this);
        eventDistributor->unregisterEventListener(OPENMSX_DELETE_BOARDS, *this);

        getGlobalSettings().getPauseSetting().detach(*this);
}

RomDatabase& Reactor::getSoftwareDatabase()
{
        if (!softwareDatabase) {
                softwareDatabase = make_unique<RomDatabase>(
                        *globalCommandController, *globalCliComm);
        }
        return *softwareDatabase;
}

CliComm& Reactor::getCliComm()
{
        return *globalCliComm;
}

Interpreter& Reactor::getInterpreter()
{
        return getGlobalCommandController().getInterpreter();
}

CommandController& Reactor::getCommandController()
{
        return *globalCommandController;
}

InfoCommand& Reactor::getOpenMSXInfoCommand()
{
        return globalCommandController->getOpenMSXInfoCommand();
}

vector<string> Reactor::getHwConfigs(string_view type)
{
        vector<string> result;
        for (auto& p : systemFileContext().getPaths()) {
                const auto& path = FileOperations::join(p, type);
                ReadDir configsDir(path);
                while (auto* entry = configsDir.getEntry()) {
                        string_view name = entry->d_name;
                        const auto& fullname = FileOperations::join(path, name);
                        if (name.ends_with(".xml") &&
                            FileOperations::isRegularFile(fullname)) {
                                name.remove_suffix(4);
                                result.push_back(name.str());
                        } else if (FileOperations::isDirectory(fullname)) {
                                const auto& config = FileOperations::join(
                                        fullname, "hardwareconfig.xml");
                                if (FileOperations::isRegularFile(config)) {
                                        result.push_back(name.str());
                                }
                        }
                }
        }
        // remove duplicates
        sort(begin(result), end(result));
        result.erase(unique(begin(result), end(result)), end(result));
        return result;
}

void Reactor::createMachineSetting()
{
        EnumSetting<int>::Map machines; // int's are unique dummy values
        int count = 1;
        for (auto& name : getHwConfigs("machines")) {
                machines.emplace_back(name, count++);
        }
        machines.emplace_back("C-BIOS_MSX2+", 0); // default machine

        machineSetting = make_unique<EnumSetting<int>>(
                *globalCommandController, "default_machine",
                "default machine (takes effect next time openMSX is started)",
                0, std::move(machines));
}

MSXMotherBoard* Reactor::getMotherBoard() const
{
        assert(Thread::isMainThread());
        return activeBoard;
}

string Reactor::getMachineID() const
{
        return activeBoard ? activeBoard->getMachineID() : string{};
}

vector<string_view> Reactor::getMachineIDs() const
{
        vector<string_view> result;
        for (auto& b : boards) {
                result.emplace_back(b->getMachineID());
        }
        return result;
}

MSXMotherBoard& Reactor::getMachine(string_view machineID) const
{
        for (auto& b : boards) {
                if (b->getMachineID() == machineID) {
                        return *b;
                }
        }
        throw CommandException("No machine with ID: ", machineID);
}

Reactor::Board Reactor::createEmptyMotherBoard()
{
        return make_unique<MSXMotherBoard>(*this);
}

void Reactor::replaceBoard(MSXMotherBoard& oldBoard_, Board newBoard_)
{
        assert(Thread::isMainThread());

        // Add new board.
        auto* newBoard = newBoard_.get();
        boards.push_back(move(newBoard_));

        // Lookup old board (it must be present).
        auto it = find_if_unguarded(boards,
                [&](Boards::value_type& b) { return b.get() == &oldBoard_; });

        // If the old board was the active board, then activate the new board
        if (it->get() == activeBoard) {
                switchBoard(newBoard);
        }

        // Remove (=delete) the old board.
        // Note that we don't use the 'garbageBoards' mechanism as used in
        // deleteBoard(). This means oldBoard cannot be used  anymore right
        // after this method returns.
        move_pop_back(boards, it);
}

void Reactor::switchMachine(const string& machine)
{
        if (!display) {
#if UNIQUE_PTR_BUG
                display2 = make_unique<Display>(*this);
                display = display2.get();
#else
                display = make_unique<Display>(*this);
#endif
                // TODO: Currently it is not possible to move this call into the
                //       constructor of Display because the call to createVideoSystem()
                //       indirectly calls Reactor.getDisplay().
                display->createVideoSystem();
        }

        // create+load new machine
        // switch to new machine
        // delete old active machine

        assert(Thread::isMainThread());
        // Note: loadMachine can throw an exception and in that case the
        //       motherboard must be considered as not created at all.
        auto newBoard_ = createEmptyMotherBoard();
        auto* newBoard = newBoard_.get();
        newBoard->loadMachine(machine);
        boards.push_back(move(newBoard_));

        auto* oldBoard = activeBoard;
        switchBoard(newBoard);
        deleteBoard(oldBoard);
}

void Reactor::switchBoard(MSXMotherBoard* newBoard)
{
        assert(Thread::isMainThread());
        assert(!newBoard ||
               (any_of(begin(boards), end(boards),
                       [&](Boards::value_type& b) { return b.get() == newBoard; })));
        assert(!activeBoard ||
               (any_of(begin(boards), end(boards),
                       [&](Boards::value_type& b) { return b.get() == activeBoard; })));
        if (activeBoard) {
                activeBoard->activate(false);
        }
        {
                // Don't hold the lock for longer than the actual switch.
                // In the past we had a potential for deadlocks here, because
                // (indirectly) the code below still acquires other locks.
                std::lock_guard<std::mutex> lock(mbMutex);
                activeBoard = newBoard;
        }
        eventDistributor->distributeEvent(
                make_shared<SimpleEvent>(OPENMSX_MACHINE_LOADED_EVENT));
        globalCliComm->update(CliComm::HARDWARE, getMachineID(), "select");
        if (activeBoard) {
                activeBoard->activate(true);
        }
}

void Reactor::deleteBoard(MSXMotherBoard* board)
{
        // Note: pass 'board' by-value to keep the parameter from changing
        // after the call to switchBoard(). switchBoard() changes the
        // 'activeBoard' member variable, so the 'board' parameter would change
        // if it were passed by reference to this method (AFAICS this only
        // happens in ~Reactor()).
        assert(Thread::isMainThread());
        if (!board) return;

        if (board == activeBoard) {
                // delete active board -> there is no active board anymore
                switchBoard(nullptr);
        }
        auto it = rfind_if_unguarded(boards,
                [&](Boards::value_type& b) { return b.get() == board; });
        auto board_ = move(*it);
        move_pop_back(boards, it);
        // Don't immediately delete old boards because it's possible this
        // routine is called via a code path that goes through the old
        // board. Instead remember this board and delete it at a safe moment
        // in time.
        garbageBoards.push_back(move(board_));
        eventDistributor->distributeEvent(
                make_shared<SimpleEvent>(OPENMSX_DELETE_BOARDS));
}

void Reactor::enterMainLoop()
{
        // Note: this method can get called from different threads
        if (Thread::isMainThread()) {
                // Don't take lock in main thread to avoid recursive locking.
                if (activeBoard) {
                        activeBoard->exitCPULoopSync();
                }
        } else {
                std::lock_guard<std::mutex> lock(mbMutex);
                if (activeBoard) {
                        activeBoard->exitCPULoopAsync();
                }
        }
}

void Reactor::run(CommandLineParser& parser)
{
        auto& commandController = *globalCommandController;

        // execute init.tcl
        try {
                commandController.source(
                        preferSystemFileContext().resolve("init.tcl"));
        } catch (FileException&) {
                // no init.tcl, ignore
        }

        // execute startup scripts
        for (auto& s : parser.getStartupScripts()) {
                try {
                        commandController.source(userFileContext().resolve(s));
                } catch (FileException& e) {
                        throw FatalError("Couldn't execute script: ",
                                         e.getMessage());
                }
        }

        // At this point openmsx is fully started, it's OK now to start
        // accepting external commands
        getGlobalCliComm().setAllowExternalCommands();

        // Run
        if (parser.getParseStatus() == CommandLineParser::RUN) {
                // don't use Tcl to power up the machine, we cannot pass
                // exceptions through Tcl and ADVRAM might throw in its
                // powerUp() method. Solution is to implement dependencies
                // between devices so ADVRAM can check the error condition
                // in its constructor
                //commandController.executeCommand("set power on");
                if (activeBoard) {
                        activeBoard->powerUp();
                }
        }

        while (running) {
                eventDistributor->deliverEvents();
                assert(garbageBoards.empty());
                bool blocked = (blockedCounter > 0) || !activeBoard;
                if (!blocked) blocked = !activeBoard->execute();
                if (blocked) {
                        // At first sight a better alternative is to use the
                        // SDL_WaitEvent() function. Though when inspecting
                        // the implementation of that function, it turns out
                        // to also use a sleep/poll loop, with even shorter
                        // sleep periods as we use here. Maybe in future
                        // SDL implementations this will be improved.
                        eventDistributor->sleep(20 * 1000);
                }
        }
}

void Reactor::unpause()
{
        if (paused) {
                paused = false;
                globalCliComm->update(CliComm::STATUS, "paused", "false");
                unblock();
        }
}

void Reactor::pause()
{
        if (!paused) {
                paused = true;
                globalCliComm->update(CliComm::STATUS, "paused", "true");
                block();
        }
}

void Reactor::block()
{
        ++blockedCounter;
        enterMainLoop();
        mixer->mute();
}

void Reactor::unblock()
{
        --blockedCounter;
        assert(blockedCounter >= 0);
        mixer->unmute();
}


// Observer<Setting>
void Reactor::update(const Setting& setting)
{
        auto& pauseSetting = getGlobalSettings().getPauseSetting();
        if (&setting == &pauseSetting) {
                if (pauseSetting.getBoolean()) {
                        pause();
                } else {
                        unpause();
                }
        }
}

// EventListener
int Reactor::signalEvent(const std::shared_ptr<const Event>& event)
{
        auto type = event->getType();
        if (type == OPENMSX_QUIT_EVENT) {
                enterMainLoop();
                running = false;
        } else if (type == OPENMSX_FOCUS_EVENT) {
#if PLATFORM_ANDROID
                // Android SDL port sends a (un)focus event when an app is put in background
                // by the OS for whatever reason (like an incoming phone call) and all screen
                // resources are taken away from the app.
                // In such case the app is supposed to behave as a good citizen
                // and minize its resource usage and related battery drain.
                // The SDL Android port already takes care of halting the Java
                // part of the sound processing. The Display class makes sure that it wont try
                // to render anything to the (temporary missing) graphics resources but the
                // main emulation should also be temporary stopped, in order to minimize CPU usage
                auto& focusEvent = checked_cast<const FocusEvent&>(*event);
                if (focusEvent.getGain()) {
                        unblock();
                } else {
                        block();
                }
#else
                // On other platforms, the user may specify if openMSX should be
                // halted on loss of focus.
                if (!getGlobalSettings().getPauseOnLostFocusSetting().getBoolean()) {
                        return 0;
                }
                auto& focusEvent = checked_cast<const FocusEvent&>(*event);
                if (focusEvent.getGain()) {
                        // gained focus
                        if (!getGlobalSettings().getPauseSetting().getBoolean()) {
                                unpause();
                        }
                } else {
                        // lost focus
                        pause();
                }
#endif
        } else if (type == OPENMSX_DELETE_BOARDS) {
                // Doesn't really matter which one we delete, just that we do
                // one per event.
                assert(!garbageBoards.empty());
                garbageBoards.pop_back();
        } else {
                UNREACHABLE; // we didn't subscribe to this event...
        }
        return 0;
}


// class QuitCommand

QuitCommand::QuitCommand(CommandController& commandController_,
                         EventDistributor& distributor_)
        : Command(commandController_, "exit")
        , distributor(distributor_)
{
}

void QuitCommand::execute(array_ref<TclObject> /*tokens*/, TclObject& /*result*/)
{
        distributor.distributeEvent(make_shared<QuitEvent>());
}

string QuitCommand::help(const vector<string>& /*tokens*/) const
{
        return "Use this command to stop the emulator\n";
}


// class MachineCommand

MachineCommand::MachineCommand(CommandController& commandController_,
                               Reactor& reactor_)
        : Command(commandController_, "machine")
        , reactor(reactor_)
{
}

void MachineCommand::execute(array_ref<TclObject> tokens, TclObject& result)
{
        switch (tokens.size()) {
        case 1: // get current machine
                // nothing
                break;
        case 2:
                try {
                        reactor.switchMachine(tokens[1].getString().str());
                } catch (MSXException& e) {
                        throw CommandException("Machine switching failed: ",
                                               e.getMessage());
                }
                break;
        default:
                throw SyntaxError();
        }
        // Always return machineID (of current or of new machine).
        result.setString(reactor.getMachineID());
}

string MachineCommand::help(const vector<string>& /*tokens*/) const
{
        return "Switch to a different MSX machine.";
}

void MachineCommand::tabCompletion(vector<string>& tokens) const
{
        completeString(tokens, Reactor::getHwConfigs("machines"));
}


// class TestMachineCommand

TestMachineCommand::TestMachineCommand(CommandController& commandController_,
                                       Reactor& reactor_)
        : Command(commandController_, "test_machine")
        , reactor(reactor_)
{
}

void TestMachineCommand::execute(array_ref<TclObject> tokens,
                                 TclObject& result)
{
        if (tokens.size() != 2) {
                throw SyntaxError();
        }
        try {
                MSXMotherBoard mb(reactor);
                mb.loadMachine(tokens[1].getString().str());
        } catch (MSXException& e) {
                result.setString(e.getMessage()); // error
        }
}

string TestMachineCommand::help(const vector<string>& /*tokens*/) const
{
        return "Test the configuration for the given machine. "
               "Returns an error message explaining why the configuration is "
               "invalid or an empty string in case of success.";
}

void TestMachineCommand::tabCompletion(vector<string>& tokens) const
{
        completeString(tokens, Reactor::getHwConfigs("machines"));
}


// class CreateMachineCommand

CreateMachineCommand::CreateMachineCommand(
        CommandController& commandController_, Reactor& reactor_)
        : Command(commandController_, "create_machine")
        , reactor(reactor_)
{
}

void CreateMachineCommand::execute(array_ref<TclObject> tokens, TclObject& result)
{
        if (tokens.size() != 1) {
                throw SyntaxError();
        }
        auto newBoard = reactor.createEmptyMotherBoard();
        result.setString(newBoard->getMachineID());
        reactor.boards.push_back(move(newBoard));
}

string CreateMachineCommand::help(const vector<string>& /*tokens*/) const
{
        return "Creates a new (empty) MSX machine. Returns the ID for the new "
               "machine.\n"
               "Use 'load_machine' to actually load a machine configuration "
               "into this new machine.\n"
               "The main reason create_machine and load_machine are two "
               "separate commands is that sometimes you already want to know "
               "the ID of the machine before load_machine starts emitting "
               "events for this machine.";
}


// class DeleteMachineCommand

DeleteMachineCommand::DeleteMachineCommand(
        CommandController& commandController_, Reactor& reactor_)
        : Command(commandController_, "delete_machine")
        , reactor(reactor_)
{
}

void DeleteMachineCommand::execute(array_ref<TclObject> tokens,
                                   TclObject& /*result*/)
{
        if (tokens.size() != 2) {
                throw SyntaxError();
        }
        reactor.deleteBoard(&reactor.getMachine(tokens[1].getString()));
}

string DeleteMachineCommand::help(const vector<string>& /*tokens*/) const
{
        return "Deletes the given MSX machine.";
}

void DeleteMachineCommand::tabCompletion(vector<string>& tokens) const
{
        completeString(tokens, reactor.getMachineIDs());
}


// class ListMachinesCommand

ListMachinesCommand::ListMachinesCommand(
        CommandController& commandController_, Reactor& reactor_)
        : Command(commandController_, "list_machines")
        , reactor(reactor_)
{
}

void ListMachinesCommand::execute(array_ref<TclObject> /*tokens*/,
                                  TclObject& result)
{
        result.addListElements(reactor.getMachineIDs());
}

string ListMachinesCommand::help(const vector<string>& /*tokens*/) const
{
        return "Returns a list of all machine IDs.";
}


// class ActivateMachineCommand

ActivateMachineCommand::ActivateMachineCommand(
        CommandController& commandController_, Reactor& reactor_)
        : Command(commandController_, "activate_machine")
        , reactor(reactor_)
{
}

void ActivateMachineCommand::execute(array_ref<TclObject> tokens,
                                     TclObject& result)
{
        switch (tokens.size()) {
        case 1:
                break;
        case 2: {
                reactor.switchBoard(&reactor.getMachine(tokens[1].getString()));
                break;
        }
        default:
                throw SyntaxError();
        }
        result.setString(reactor.getMachineID());
}

string ActivateMachineCommand::help(const vector<string>& /*tokens*/) const
{
        return "Make another machine the active msx machine.\n"
               "Or when invoked without arguments, query the ID of the "
               "active msx machine.";
}

void ActivateMachineCommand::tabCompletion(vector<string>& tokens) const
{
        completeString(tokens, reactor.getMachineIDs());
}


// class StoreMachineCommand

StoreMachineCommand::StoreMachineCommand(
        CommandController& commandController_, Reactor& reactor_)
        : Command(commandController_, "store_machine")
        , reactor(reactor_)
{
}

void StoreMachineCommand::execute(array_ref<TclObject> tokens, TclObject& result)
{
        string filename;
        string_view machineID;
        switch (tokens.size()) {
        case 1:
                machineID = reactor.getMachineID();
                filename = FileOperations::getNextNumberedFileName("savestates", "openmsxstate", ".xml.gz");
                break;
        case 2:
                machineID = tokens[1].getString();
                filename = FileOperations::getNextNumberedFileName("savestates", "openmsxstate", ".xml.gz");
                break;
        case 3:
                machineID = tokens[1].getString();
                filename = tokens[2].getString().str();
                break;
        default:
                throw SyntaxError();
        }

        auto& board = reactor.getMachine(machineID);

        XmlOutputArchive out(filename);
        out.serialize("machine", board);
        result.setString(filename);
}

string StoreMachineCommand::help(const vector<string>& /*tokens*/) const
{
        return
                "store_machine                       Save state of current machine to file \"openmsxNNNN.xml.gz\"\n"
                "store_machine machineID             Save state of machine \"machineID\" to file \"openmsxNNNN.xml.gz\"\n"
                "store_machine machineID <filename>  Save state of machine \"machineID\" to indicated file\n"
                "\n"
                "This is a low-level command, the 'savestate' script is easier to use.";
}

void StoreMachineCommand::tabCompletion(vector<string>& tokens) const
{
        completeString(tokens, reactor.getMachineIDs());
}


// class RestoreMachineCommand

RestoreMachineCommand::RestoreMachineCommand(
        CommandController& commandController_, Reactor& reactor_)
        : Command(commandController_, "restore_machine")
        , reactor(reactor_)
{
}

void RestoreMachineCommand::execute(array_ref<TclObject> tokens,
                                    TclObject& result)
{
        auto newBoard = reactor.createEmptyMotherBoard();

        string filename;
        switch (tokens.size()) {
        case 1: {
                // load last saved entry
                struct stat st;
                string dirName = FileOperations::getUserOpenMSXDir() + "/savestates/";
                string lastEntry;
                time_t lastTime = 0;
                ReadDir dir(dirName);
                while (dirent* d = dir.getEntry()) {
                        int res = stat(strCat(dirName, d->d_name).c_str(), &st);
                        if ((res == 0) && S_ISREG(st.st_mode)) {
                                time_t modTime = st.st_mtime;
                                if (modTime > lastTime) {
                                        lastEntry = string(d->d_name);
                                        lastTime = modTime;
                                }
                        }
                }
                if (lastEntry.empty()) {
                        throw CommandException("Can't find last saved state.");
                }
                filename = dirName + lastEntry;
                break;
        }
        case 2:
                filename = tokens[1].getString().str();
                break;
        default:
                throw SyntaxError();
        }

        //std::cerr << "Loading " << filename << std::endl;
        try {
                XmlInputArchive in(filename);
                in.serialize("machine", *newBoard);
        } catch (XMLException& e) {
                throw CommandException("Cannot load state, bad file format: ",
                                       e.getMessage());
        } catch (MSXException& e) {
                throw CommandException("Cannot load state: ", e.getMessage());
        }

        // Savestate also contains stuff like the keyboard state at the moment
        // the snapshot was created (this is required for reverse/replay). But
        // now we want the MSX to see the actual host keyboard state.
        newBoard->getStateChangeDistributor().stopReplay(newBoard->getCurrentTime());

        result.setString(newBoard->getMachineID());
        reactor.boards.push_back(move(newBoard));
}

string RestoreMachineCommand::help(const vector<string>& /*tokens*/) const
{
        return "restore_machine                       Load state from last saved state in default directory\n"
               "restore_machine <filename>            Load state from indicated file\n"
               "\n"
               "This is a low-level command, the 'loadstate' script is easier to use.";
}

void RestoreMachineCommand::tabCompletion(vector<string>& tokens) const
{
        // TODO: add the default files (state files in user's savestates dir)
        completeFileName(tokens, userFileContext());
}


// class ConfigInfo

ConfigInfo::ConfigInfo(InfoCommand& openMSXInfoCommand,
                       const string& configName_)
        : InfoTopic(openMSXInfoCommand, configName_)
        , configName(configName_)
{
}

void ConfigInfo::execute(array_ref<TclObject> tokens, TclObject& result) const
{
        // TODO make meta info available through this info topic
        switch (tokens.size()) {
        case 2: {
                result.addListElements(Reactor::getHwConfigs(configName));
                break;
        }
        case 3: {
                try {
                        auto config = HardwareConfig::loadConfig(
                                configName, tokens[2].getString());
                        if (auto* info = config.findChild("info")) {
                                for (auto& i : info->getChildren()) {
                                        result.addListElement(i.getName());
                                        result.addListElement(i.getData());
                                }
                        }
                } catch (MSXException& e) {
                        throw CommandException(
                                "Couldn't get config info: ", e.getMessage());
                }
                break;
        }
        default:
                throw CommandException("Too many parameters");
        }
}

string ConfigInfo::help(const vector<string>& /*tokens*/) const
{
        return strCat("Shows a list of available ", configName, ", "
                      "or get meta information about the selected item.\n");
}

void ConfigInfo::tabCompletion(vector<string>& tokens) const
{
        completeString(tokens, Reactor::getHwConfigs(configName));
}


// class RealTimeInfo

RealTimeInfo::RealTimeInfo(InfoCommand& openMSXInfoCommand)
        : InfoTopic(openMSXInfoCommand, "realtime")
        , reference(Timer::getTime())
{
}

void RealTimeInfo::execute(array_ref<TclObject> /*tokens*/,
                           TclObject& result) const
{
        auto delta = Timer::getTime() - reference;
        result.setDouble(delta / 1000000.0);
}

string RealTimeInfo::help(const vector<string>& /*tokens*/) const
{
        return "Returns the time in seconds since openMSX was started.";
}

} // namespace openmsx