Fix and cleanup modern tick loop (#253)

patches/server/0004-Backport-modern-tick-loop.patch

@@ -231,7 +231,7 @@ index 088beb22b53ddf77dc182dd5ac39e1086d5279aa..6434b8613971a228fb0074390d8223bf
          Thread thread = new Thread("Server Infinisleeper") {
              {
 diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
-index 7d19ec833d61c2f75b5eb75d7eb291c7366a1a9a..eae936650fddd5ef418ee2ddd680d36e82045365 100644
+index 7d19ec833d61c2f75b5eb75d7eb291c7366a1a9a..f411b611fc8b35fc60882d0123f01de49380b4b0 100644
 --- a/src/main/java/net/minecraft/server/MinecraftServer.java
 +++ b/src/main/java/net/minecraft/server/MinecraftServer.java
 @@ -48,7 +48,7 @@ import org.bukkit.craftbukkit.Main;
@@ -243,13 +243,21 @@ index 7d19ec833d61c2f75b5eb75d7eb291c7366a1a9a..eae936650fddd5ef418ee2ddd680d36e
 
      public static final Logger LOGGER = LogManager.getLogger();
      public static final File a = new File("usercache.json");
-@@ -117,7 +117,36 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
+@@ -102,7 +102,7 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
+     private final UserCache Z;
+     protected final Queue<FutureTask<?>> j = new java.util.concurrent.ConcurrentLinkedQueue<FutureTask<?>>(); // Spigot, PAIL: Rename
+     private Thread serverThread;
+-    private long ab = az();
++    private long ab; // PandaSpigot - The az() initializer is redundant
+
+     // CraftBukkit start
+     public List<WorldServer> worlds = new ArrayList<WorldServer>();
+@@ -117,7 +117,35 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
      public int autosavePeriod;
      // CraftBukkit end
 
 -    public MinecraftServer(OptionSet options, Proxy proxy, File file1) {
 +    // PandaSpigot start - Modern tick loop
-+    private long nextTickTime;
 +    private long delayedTasksMaxNextTickTime;
 +    private boolean mayHaveDelayedTasks;
 +    private boolean forceTicks;
@@ -274,14 +282,14 @@ index 7d19ec833d61c2f75b5eb75d7eb291c7366a1a9a..eae936650fddd5ef418ee2ddd680d36e
 +
 +    public MinecraftServer(OptionSet options, Proxy proxy, File file1, Thread thread) {
 +        super("Server");
-+        this.nextTickTime = getMillis();
++        this.ab = az();
 +        this.primaryThread = thread;
 +        this.serverThread = thread;
 +    // PandaSpigot end
          io.netty.util.ResourceLeakDetector.setEnabled( false ); // Spigot - disable
          this.e = proxy;
          MinecraftServer.l = this;
-@@ -154,7 +183,7 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
+@@ -154,7 +182,7 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
          }
          Runtime.getRuntime().addShutdownHook(new org.bukkit.craftbukkit.util.ServerShutdownThread(this));
 
@@ -290,22 +298,14 @@ index 7d19ec833d61c2f75b5eb75d7eb291c7366a1a9a..eae936650fddd5ef418ee2ddd680d36e
      }
 
      public abstract PropertyManager getPropertyManager();
-@@ -557,12 +586,21 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
-         }
+@@ -558,11 +586,14 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
      }
      // PaperSpigot End
-- 
-+
+
 +    // PandaSpigot start - Modern tick loop
-+    public static long getMillis() {
-+        return getNanos() / 1000000L;
-+    }
-+    public static long getNanos() {
-+        return System.nanoTime();
-+    }
      public void run() {
          try {
-+            this.serverStartTime = getNanos();
++            this.serverStartTime = az();
 +    // PandaSpigot end
              if (this.init()) {
                  this.ab = az();
@@ -314,7 +314,7 @@ index 7d19ec833d61c2f75b5eb75d7eb291c7366a1a9a..eae936650fddd5ef418ee2ddd680d36e
 
                  this.r.setMOTD(new ChatComponentText(this.motd));
                  this.r.setServerInfo(new ServerPing.ServerData("1.8.8", 47));
-@@ -572,31 +610,21 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
+@@ -572,31 +603,21 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
                  // PaperSpigot start - Further improve tick loop
                  Arrays.fill( recentTps, 20 );
                  //long lastTick = System.nanoTime(), catchupTime = 0, curTime, wait, tickSection = lastTick;
@@ -339,61 +339,61 @@ index 7d19ec833d61c2f75b5eb75d7eb291c7366a1a9a..eae936650fddd5ef418ee2ddd680d36e
 -                            wait -= catchupTime;
 -                            catchupTime -= catchupTime;
 -                        }
--                    }
--                    if (wait > 0) {
--                        Thread.sleep(wait / 1000000);
--                        wait = TICK_TIME - (curTime - lastTick);
 +                    // PandaSpigot start - Modern tick loop
-+                    long i = ((curTime = System.nanoTime()) / (1000L * 1000L)) - this.nextTickTime; // Paper
-+                    if (i > 5000L && this.nextTickTime - this.lastOverloadWarning >= 30000L && ticks > 500) { // CraftBukkit
++                    long i = ((curTime = System.nanoTime()) / (1000L * 1000L)) - ab;
++                    if (i > 5000L && this.ab - this.lastOverloadWarning >= 30000L && ticks > 500) {
 +                        long j = i / 50L;
 +                        if (this.server.getWarnOnOverload()) // CraftBukkit
 +                            MinecraftServer.LOGGER.warn("Can't keep up! Is the server overloaded? Running {}ms or {} ticks behind", i, j);
-+                        this.nextTickTime += j * 50L;
-+                        this.lastOverloadWarning = this.nextTickTime;
++                        this.ab += j * 50L;
++                        this.lastOverloadWarning = this.ab;
                      }
+-                    if (wait > 0) {
+-                        Thread.sleep(wait / 1000000);
+-                        wait = TICK_TIME - (curTime - lastTick);
+-                    }
 -
 -                    catchupTime = Math.min(MAX_CATCHUP_BUFFER, catchupTime - wait);
 -
                      if ( ++MinecraftServer.currentTick % SAMPLE_INTERVAL == 0 )
                      {
                          final long diff = curTime - tickSection;
-@@ -613,8 +641,16 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
+@@ -613,8 +634,16 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
                      }
                      lastTick = curTime;
 
 -                    this.A();
 -                    this.Q = true;
-+                    this.nextTickTime += 50L;
++                    this.ab += 50L;
 +                    this.methodProfiler.a("tick");
 +                    this.A(this::haveTime);
 +                    this.methodProfiler.c("nextTickWait");
 +                    this.mayHaveDelayedTasks = true;
-+                    this.delayedTasksMaxNextTickTime = Math.max(getMillis() + 50L, this.nextTickTime);
++                    this.delayedTasksMaxNextTickTime = Math.max(az() + 50L, this.ab);
 +                    this.waitUntilNextTick();
 +                    this.methodProfiler.b();
 +                    this.isReady = true;
 +                    // PandaSpigot end
                  }
                  // Spigot end
              } else {
-@@ -665,6 +701,62 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
+@@ -665,6 +694,62 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
          }
 
      }
 +    // PandaSpigot start - Modern tick loop
 +    private boolean haveTime() {
 +        if (isOversleep) return canOversleep();
-+        return this.forceTicks || this.runningTask() || getMillis() < (this.mayHaveDelayedTasks ? this.delayedTasksMaxNextTickTime : this.nextTickTime);
++        return this.forceTicks || this.runningTask() || az() < (this.mayHaveDelayedTasks ? this.delayedTasksMaxNextTickTime : this.ab);
 +    }
 +
 +    boolean isOversleep = false;
 +    private boolean canOversleep() {
-+        return this.mayHaveDelayedTasks && getMillis() < this.delayedTasksMaxNextTickTime;
++        return this.mayHaveDelayedTasks && az() < this.delayedTasksMaxNextTickTime;
 +    }
 +
 +    private boolean canSleepForTickNoOversleep() {
-+        return this.forceTicks || this.runningTask() || getMillis() < this.nextTickTime;
++        return this.forceTicks || this.runningTask() || az() < this.ab;
 +    }
 +
 +    private void executeModerately() {
@@ -440,7 +440,7 @@ index 7d19ec833d61c2f75b5eb75d7eb291c7366a1a9a..eae936650fddd5ef418ee2ddd680d36e
 
      private void a(ServerPing serverping) {
          File file = this.d("server-icon.png");
-@@ -698,9 +790,15 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
+@@ -698,9 +783,15 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
 
      protected void z() {}
 
@@ -457,7 +457,7 @@ index 7d19ec833d61c2f75b5eb75d7eb291c7366a1a9a..eae936650fddd5ef418ee2ddd680d36e
 
          ++this.ticks;
          if (this.T) {
-@@ -744,6 +842,11 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
+@@ -744,6 +835,11 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
              SpigotTimings.worldSaveTimer.stopTiming(); // Spigot
          }
 
@@ -469,31 +469,52 @@ index 7d19ec833d61c2f75b5eb75d7eb291c7366a1a9a..eae936650fddd5ef418ee2ddd680d36e
          this.methodProfiler.a("tallying");
          this.h[this.ticks % 100] = System.nanoTime() - i;
          this.methodProfiler.b();
-@@ -981,6 +1084,7 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
+@@ -981,6 +1077,7 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
              });
              */
 
 +            /* // PandaSpigot start - comment out
              DedicatedServer dedicatedserver = new DedicatedServer(options);
 
              if (options.has("port")) {
-@@ -1000,6 +1104,7 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
+@@ -1000,6 +1097,7 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
 
              dedicatedserver.primaryThread.start();
              // CraftBukkit end
 +            */ // PandaSpigot end
          } catch (Exception exception) {
              MinecraftServer.LOGGER.fatal("Failed to start the minecraft server", exception);
          }
-@@ -1483,7 +1588,7 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
+@@ -1483,7 +1581,7 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
      }
 
      public static long az() {
 -        return System.currentTimeMillis();
-+        return getMillis(); // PandaSpigot - Modern tick loop
++        return SystemUtils.getMonotonicMillis(); // PandaSpigot - Modern tick loop
      }
 
      public int getIdleTimeout() {
+diff --git a/src/main/java/net/minecraft/server/SystemUtils.java b/src/main/java/net/minecraft/server/SystemUtils.java
+index e65ffc1566784f8a35a4a620514375b9077ce247..0c23e540a300590f967a681a3a8cf65bfc4f1377 100644
+--- a/src/main/java/net/minecraft/server/SystemUtils.java
++++ b/src/main/java/net/minecraft/server/SystemUtils.java
+@@ -6,6 +6,16 @@ import org.apache.logging.log4j.Logger;
+
+ public class SystemUtils {
+
++    // PandaSpigot start - Modern Tick Loop
++    public static long getMonotonicMillis() {
++        return getMonotonicNanos() / 1000000L;
++    }
++
++    public static long getMonotonicNanos() {
++        return System.nanoTime();
++    }
++    // PandaSpigot end
++
+     public static <V> V a(FutureTask<V> futuretask, Logger logger) {
+         try {
+             futuretask.run();
 diff --git a/src/main/java/org/bukkit/craftbukkit/Main.java b/src/main/java/org/bukkit/craftbukkit/Main.java
 index c936219196ea403a9d247ad6c8c0ffee79411da2..5c980fe2907d2ff01be793ab0654ab198f46e519 100644
 --- a/src/main/java/org/bukkit/craftbukkit/Main.java

patches/server/0013-Consolidate-flush-calls-for-entity-tracker-packets.patch

@@ -6,10 +6,10 @@ Subject: [PATCH] Consolidate flush calls for entity tracker packets
 Most server packets seem to be sent from here, so try to avoid expensive flush calls from them.
 
 diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
-index eae936650fddd5ef418ee2ddd680d36e82045365..06e023994050a07d2efed174b1fbd8f1eddcd231 100644
+index 15202423fba6a0661222a00be2c0aa1b5d64e906..7e6bad78c9b7a05d1def63a77610fd6c332b8c85 100644
 --- a/src/main/java/net/minecraft/server/MinecraftServer.java
 +++ b/src/main/java/net/minecraft/server/MinecraftServer.java
-@@ -963,7 +963,26 @@ public abstract class MinecraftServer extends com.hpfxd.pandaspigot.tickloop.Ree
+@@ -956,7 +956,26 @@ public abstract class MinecraftServer extends com.hpfxd.pandaspigot.tickloop.Ree
                  this.methodProfiler.b();
                  this.methodProfiler.a("tracker");
                  worldserver.timings.tracker.startTiming(); // Spigot

patches/server/0017-Optimize-World-Time-Updates.patch

@@ -8,10 +8,10 @@ the updates per world, so that we can re-use the same packet
 object for every player unless they have per-player time enabled.
 
 diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
-index 06e023994050a07d2efed174b1fbd8f1eddcd231..8f394d5fe6f0f0640a942f15ae69582bfd70b4c8 100644
+index 7e6bad78c9b7a05d1def63a77610fd6c332b8c85..f213f9db49acb9efff02178556d6eec969f4d9c1 100644
 --- a/src/main/java/net/minecraft/server/MinecraftServer.java
 +++ b/src/main/java/net/minecraft/server/MinecraftServer.java
-@@ -899,12 +899,24 @@ public abstract class MinecraftServer extends com.hpfxd.pandaspigot.tickloop.Ree
+@@ -892,12 +892,24 @@ public abstract class MinecraftServer extends com.hpfxd.pandaspigot.tickloop.Ree
 
          SpigotTimings.timeUpdateTimer.startTiming(); // Spigot
          // Send time updates to everyone, it will get the right time from the world the player is in.

patches/server/0018-Configurable-time-update-frequency.patch

@@ -23,10 +23,10 @@ index 3dd3d0702c17541083d0d365ca46e93602105bce..b5f16e8cab9e43ad7597b2ea5bc92139
      public KnockbackConfig knockback;
 
 diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
-index 8f394d5fe6f0f0640a942f15ae69582bfd70b4c8..b7decb879f530345b82722aeb1294864feecd2c2 100644
+index f213f9db49acb9efff02178556d6eec969f4d9c1..eafa8ca822b79c8f31e43b484ce27b500a979bf5 100644
 --- a/src/main/java/net/minecraft/server/MinecraftServer.java
 +++ b/src/main/java/net/minecraft/server/MinecraftServer.java
-@@ -906,7 +906,7 @@ public abstract class MinecraftServer extends com.hpfxd.pandaspigot.tickloop.Ree
+@@ -899,7 +899,7 @@ public abstract class MinecraftServer extends com.hpfxd.pandaspigot.tickloop.Ree
              long worldTime = world.getTime();
              final PacketPlayOutUpdateTime worldPacket = new PacketPlayOutUpdateTime(worldTime, dayTime, doDaylight);
              for (EntityHuman entityhuman : world.players) {

patches/server/0023-EntityMoveEvent.patch

@@ -31,10 +31,10 @@ index 72c7e6fc8bb0a71877d6759af44d39030bcf51f5..1353a791235ae3b820072fa80ef60c3c
 
      protected void doTick() {}
 diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
-index b7decb879f530345b82722aeb1294864feecd2c2..66d4c410c2bcc345bf09e07a63de7534064524d2 100644
+index eafa8ca822b79c8f31e43b484ce27b500a979bf5..5a0cf1ba4d7f7fbc9b62a60201682244e5dd56ff 100644
 --- a/src/main/java/net/minecraft/server/MinecraftServer.java
 +++ b/src/main/java/net/minecraft/server/MinecraftServer.java
-@@ -926,6 +926,7 @@ public abstract class MinecraftServer extends com.hpfxd.pandaspigot.tickloop.Ree
+@@ -919,6 +919,7 @@ public abstract class MinecraftServer extends com.hpfxd.pandaspigot.tickloop.Ree
 
              // if (i == 0 || this.getAllowNether()) {
                  WorldServer worldserver = this.worlds.get(i);

patches/server/0030-Cleanup-allocated-favicon-ByteBuf.patch

@@ -7,18 +7,18 @@ Cleanups a bytebuffer which was allocated during the encoding of the
 favicon to be sent to the client.
 
 diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
-index f6d1510fc16fc48be221cc7bb5968a132a2b9752..faf566f647d161160c6c01ae4fa500f38dc61b8c 100644
+index 5a0cf1ba4d7f7fbc9b62a60201682244e5dd56ff..348c63892aef13e70f38cbc7989c0b4d994873b9 100644
 --- a/src/main/java/net/minecraft/server/MinecraftServer.java
 +++ b/src/main/java/net/minecraft/server/MinecraftServer.java
-@@ -763,6 +763,7 @@ public abstract class MinecraftServer extends com.hpfxd.pandaspigot.tickloop.Ree
+@@ -756,6 +756,7 @@ public abstract class MinecraftServer extends com.hpfxd.pandaspigot.tickloop.Ree
 
          if (file.isFile()) {
              ByteBuf bytebuf = Unpooled.buffer();
 +            ByteBuf bytebuf1 = null; // PandaSpigot - cleanup favicon bytebuf
 
              try {
                  BufferedImage bufferedimage = ImageIO.read(file);
-@@ -770,13 +771,14 @@ public abstract class MinecraftServer extends com.hpfxd.pandaspigot.tickloop.Ree
+@@ -763,13 +764,14 @@ public abstract class MinecraftServer extends com.hpfxd.pandaspigot.tickloop.Ree
                  Validate.validState(bufferedimage.getWidth() == 64, "Must be 64 pixels wide", new Object[0]);
                  Validate.validState(bufferedimage.getHeight() == 64, "Must be 64 pixels high", new Object[0]);
                  ImageIO.write(bufferedimage, "PNG", new ByteBufOutputStream(bytebuf));

patches/server/0035-Optimize-Network-Queue.patch

@@ -45,7 +45,7 @@ index 0000000000000000000000000000000000000000..c8540d16defdc633113b504616794f44
 +    }
 +}
 diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
-index b784f8174b94c6fab41ed3262009383a2ffba3cc..26f1e07cefd54afe3df1b8ce8e4d58b26619c8d3 100644
+index e6466f470adddbaf438b98c559a27d5d13bccacd..6392695bf426536709967f744d511ed9de823a96 100644
 --- a/src/main/java/net/minecraft/server/MinecraftServer.java
 +++ b/src/main/java/net/minecraft/server/MinecraftServer.java
 @@ -100,7 +100,7 @@ public abstract class MinecraftServer extends com.hpfxd.pandaspigot.tickloop.Ree
@@ -55,5 +55,5 @@ index b784f8174b94c6fab41ed3262009383a2ffba3cc..26f1e07cefd54afe3df1b8ce8e4d58b2
 -    protected final Queue<FutureTask<?>> j = new java.util.concurrent.ConcurrentLinkedQueue<FutureTask<?>>(); // Spigot, PAIL: Rename
 +    protected final Queue<FutureTask<?>> j = new com.destroystokyo.paper.utils.CachedSizeConcurrentLinkedQueue<>(); // Spigot, PAIL: Rename // PandaSpigot - Make size() constant-time
      private Thread serverThread;
-     private long ab = az();
+     private long ab; // PandaSpigot - The az() initializer is redundant
 

patches/server/0036-Backport-PlayerProfile-API.patch

@@ -320,10 +320,10 @@ index 9034e1ad7a013c7288e68322a65798e40d8b851d..86ab9994079c6e18e3aed885db4171d0
      public EntityFishingHook hookedFish;
      public boolean affectsSpawning = true; // PaperSpigot
 diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
-index 0f893196390e04f8c512f401612c5d455e25bec1..75716099df3c3afc9e5857258ed6d1b271c4b957 100644
+index 8cfc553b059db22a2deb4c86210edb705d41e2ac..ad16adf4dc9775bc7c2553d6a67b4ff08f52cc1d 100644
 --- a/src/main/java/net/minecraft/server/MinecraftServer.java
 +++ b/src/main/java/net/minecraft/server/MinecraftServer.java
-@@ -1641,6 +1641,7 @@ public abstract class MinecraftServer extends com.hpfxd.pandaspigot.tickloop.Ree
+@@ -1634,6 +1634,7 @@ public abstract class MinecraftServer extends com.hpfxd.pandaspigot.tickloop.Ree
          return true;
      }