bmc_state_manager.hpp

#pragma once

#include <functional>
#include <sdbusplus/bus.hpp>
#include "xyz/openbmc_project/State/BMC/server.hpp"

namespace phosphor
{
namespace state
{
namespace manager
{

using BMCInherit = sdbusplus::server::object::object<
        sdbusplus::xyz::openbmc_project::State::server::BMC>;
namespace sdbusRule = sdbusplus::bus::match::rules;


/** @class BMC
 *  @brief OpenBMC BMC state management implementation.
 *  @details A concrete implementation for xyz.openbmc_project.State.BMC
 *  DBus API.
 */
class BMC : public BMCInherit
{
    public:
        /** @brief Constructs BMC State Manager
         *
         * @param[in] bus       - The Dbus bus object
         * @param[in] busName   - The Dbus name to own
         * @param[in] objPath   - The Dbus object path
         */
        BMC(sdbusplus::bus::bus& bus,
            const char* objPath) :
                BMCInherit(bus, objPath, true),
                bus(bus),
                stateSignal(
                        std::make_unique<decltype(stateSignal)::element_type>(
                                bus,
                                sdbusRule::type::signal() +
                                sdbusRule::member("JobRemoved") +
                                sdbusRule::path("/org/freedesktop/systemd1") +
                                sdbusRule::interface(
                                        "org.freedesktop.systemd1.Manager"),
                                std::bind(std::mem_fn(&BMC::bmcStateChange),
                                          this, std::placeholders::_1)))
        {
            subscribeToSystemdSignals();
            discoverInitialState();
            this->emit_object_added();
        };

        /** @brief Set value of BMCTransition **/
        Transition requestedBMCTransition(Transition value) override;

        /** @brief Set value of CurrentBMCState **/
        BMCState currentBMCState(BMCState value) override;

    private:
        /**
         * @brief discover the state of the bmc
         **/
        void discoverInitialState();

        /**
         * @brief subscribe to the systemd signals
         **/
        void subscribeToSystemdSignals();

        /** @brief Execute the transition request
         *
         *  @param[in] tranReq   - Transition requested
         */
        void executeTransition(Transition tranReq);

        /** @brief Callback function on bmc state change
         *
         * Check if the state is relevant to the BMC and if so, update
         * corresponding BMC object's state
         *
         * @param[in]  msg       - Data associated with subscribed signal
         *
         */
        int bmcStateChange(sdbusplus::message::message& msg);

        /** @brief Persistent sdbusplus DBus bus connection. **/
        sdbusplus::bus::bus& bus;

        /** @brief Used to subscribe to dbus system state changes **/
        std::unique_ptr<sdbusplus::bus::match_t> stateSignal;
};

} // namespace manager
} // namespace state
} // namespace phosphor