DeltaZern/paper-server/src/main/java/org/spigotmc/WatchdogThread.java

package org.spigotmc;

import java.lang.management.ManagementFactory;
import java.lang.management.MonitorInfo;
import java.lang.management.ThreadInfo;
import java.util.logging.Level;
import java.util.logging.Logger;
import net.minecraft.server.MinecraftServer;
import org.bukkit.Bukkit;

public class WatchdogThread extends Thread
{

    private static WatchdogThread instance;
    private long timeoutTime;
    private boolean restart;
    private volatile long lastTick;
    private volatile boolean stopping;

    private WatchdogThread(long timeoutTime, boolean restart)
    {
        super( "Spigot Watchdog Thread" );
        this.timeoutTime = timeoutTime;
        this.restart = restart;
    }

    private static long monotonicMillis()
    {
        return System.nanoTime() / 1000000L;
    }

    public static void doStart(int timeoutTime, boolean restart)
    {
        if ( WatchdogThread.instance == null )
        {
            WatchdogThread.instance = new WatchdogThread( timeoutTime * 1000L, restart );
            WatchdogThread.instance.start();
        } else
        {
            WatchdogThread.instance.timeoutTime = timeoutTime * 1000L;
            WatchdogThread.instance.restart = restart;
        }
    }

    public static void tick()
    {
        WatchdogThread.instance.lastTick = WatchdogThread.monotonicMillis();
    }

    public static void doStop()
    {
        if ( WatchdogThread.instance != null )
        {
            WatchdogThread.instance.stopping = true;
        }
    }

    @Override
    public void run()
    {
        while ( !this.stopping )
        {
            //
            if ( this.lastTick != 0 && this.timeoutTime > 0 && WatchdogThread.monotonicMillis() > this.lastTick + this.timeoutTime )
            {
                Logger log = Bukkit.getServer().getLogger();
                log.log( Level.SEVERE, "------------------------------" );
                log.log( Level.SEVERE, "The server has stopped responding! This is (probably) not a Spigot bug." );
                log.log( Level.SEVERE, "If you see a plugin in the Server thread dump below, then please report it to that author" );
                log.log( Level.SEVERE, "\t *Especially* if it looks like HTTP or MySQL operations are occurring" );
                log.log( Level.SEVERE, "If you see a world save or edit, then it means you did far more than your server can handle at once" );
                log.log( Level.SEVERE, "\t If this is the case, consider increasing timeout-time in spigot.yml but note that this will replace the crash with LARGE lag spikes" );
                log.log( Level.SEVERE, "If you are unsure or still think this is a Spigot bug, please report to https://www.spigotmc.org/" );
                log.log( Level.SEVERE, "Be sure to include ALL relevant console errors and Minecraft crash reports" );
                log.log( Level.SEVERE, "Spigot version: " + Bukkit.getServer().getVersion() );
                //
                if ( net.minecraft.world.level.Level.lastPhysicsProblem != null )
                {
                    log.log( Level.SEVERE, "------------------------------" );
                    log.log( Level.SEVERE, "During the run of the server, a physics stackoverflow was supressed" );
                    log.log( Level.SEVERE, "near " + net.minecraft.world.level.Level.lastPhysicsProblem );
                }
                //
                log.log( Level.SEVERE, "------------------------------" );
                log.log( Level.SEVERE, "Server thread dump (Look for plugins here before reporting to Spigot!):" );
                WatchdogThread.dumpThread( ManagementFactory.getThreadMXBean().getThreadInfo( MinecraftServer.getServer().serverThread.getId(), Integer.MAX_VALUE ), log );
                log.log( Level.SEVERE, "------------------------------" );
                //
                log.log( Level.SEVERE, "Entire Thread Dump:" );
                ThreadInfo[] threads = ManagementFactory.getThreadMXBean().dumpAllThreads( true, true );
                for ( ThreadInfo thread : threads )
                {
                    WatchdogThread.dumpThread( thread, log );
                }
                log.log( Level.SEVERE, "------------------------------" );

                if ( this.restart && !MinecraftServer.getServer().hasStopped() )
                {
                    RestartCommand.restart();
                }
                break;
            }

            try
            {
                sleep( 10000 );
            } catch ( InterruptedException ex )
            {
                this.interrupt();
            }
        }
    }

    private static void dumpThread(ThreadInfo thread, Logger log)
    {
        log.log( Level.SEVERE, "------------------------------" );
        //
        log.log( Level.SEVERE, "Current Thread: " + thread.getThreadName() );
        log.log( Level.SEVERE, "\tPID: " + thread.getThreadId()
                + " | Suspended: " + thread.isSuspended()
                + " | Native: " + thread.isInNative()
                + " | State: " + thread.getThreadState() );
        if ( thread.getLockedMonitors().length != 0 )
        {
            log.log( Level.SEVERE, "\tThread is waiting on monitor(s):" );
            for ( MonitorInfo monitor : thread.getLockedMonitors() )
            {
                log.log( Level.SEVERE, "\t\tLocked on:" + monitor.getLockedStackFrame() );
            }
        }
        log.log( Level.SEVERE, "\tStack:" );
        //
        for ( StackTraceElement stack : thread.getStackTrace() )
        {
            log.log( Level.SEVERE, "\t\t" + stack );
        }
    }
}