LoadManager.h

#pragma once
 
#include <xrpl/beast/utility/Journal.h>
 
#include <chrono>
#include <condition_variable>
#include <memory>
#include <mutex>
#include <thread>
 
namespace xrpl {
 
class Application;

class LoadManager
{
    LoadManager(Application& app, beast::Journal journal);
 
public:
    LoadManager() = delete;
    LoadManager(LoadManager const&) = delete;
    LoadManager&
    operator=(LoadManager const&) = delete;

    ~LoadManager();

    // VFALCO NOTE it seems that the stall detector has an "armed" state
    //             to prevent it from going off during program startup if
    //             there's a lengthy initialization operation taking place?
    //
    void
    activateStallDetector();

    void
    heartbeat();
 
    //--------------------------------------------------------------------------
 
    void
    start();
 
    void
    stop();
 
private:
    void
    run();
 
private:
    Application& app_;
    beast::Journal const journal_;
 
    std::thread thread_;
    std::mutex mutex_;  // Guards lastHeartbeat_, armed_, cv_
    std::condition_variable cv_;
    bool stop_ = false;
 
    // Detect server stalls
    std::chrono::steady_clock::time_point lastHeartbeat_;
    bool armed_;
 
    friend std::unique_ptr<LoadManager>
    makeLoadManager(Application& app, beast::Journal journal);
};
 
std::unique_ptr<LoadManager>
makeLoadManager(Application& app, beast::Journal journal);
 
}  // namespace xrpl