Paper/patches/server/0024-Further-improve-server-tick-loop.patch
Nassim Jahnke 06db5d08b0
Updated Upstream (Bukkit/CraftBukkit) (#6589)
Upstream has released updates that appear to apply and compile correctly.
This update has not been tested by PaperMC and as with ANY update, please do your own testing

Bukkit Changes:
44cfe143 SPIGOT-6249: Add Missing Effect Constants

CraftBukkit Changes:
14928261 SPIGOT-6249: Add Missing Effect Constants
332335e1 SPIGOT-6731: "Nag author" message in CraftServer lists one author only
6cd975d0 SPIGOT-5732, SPIGOT-6387: Overhaul Hanging entities
2021-09-11 19:27:48 +02:00

213 lines
12 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Tue, 1 Mar 2016 23:09:29 -0600
Subject: [PATCH] Further improve server tick loop
Improves how the catchup buffer is handled, allowing it to roll both ways
increasing the effeciency of the thread sleep so it only will sleep once.
Also increases the buffer of the catchup to ensure server stays at 20 TPS unless extreme conditions
Previous implementation did not calculate TPS correctly.
Switch to a realistic rolling average and factor in std deviation as an extra reporting variable
diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index c24c5c39103fd2ae37711b745fef74c44ac18565..d9a305f39a4004f28ad5f8c35db1016c1bedea16 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -283,7 +283,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
public org.bukkit.command.ConsoleCommandSender console;
public org.bukkit.command.RemoteConsoleCommandSender remoteConsole;
public ConsoleReader reader;
- public static int currentTick = (int) (System.currentTimeMillis() / 50);
+ public static int currentTick = 0; // Paper - Further improve tick loop
public java.util.Queue<Runnable> processQueue = new java.util.concurrent.ConcurrentLinkedQueue<Runnable>();
public int autosavePeriod;
public Commands vanillaCommandDispatcher;
@@ -292,7 +292,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
// Spigot start
public static final int TPS = 20;
public static final int TICK_TIME = 1000000000 / MinecraftServer.TPS;
- private static final int SAMPLE_INTERVAL = 100;
+ private static final int SAMPLE_INTERVAL = 20; // Paper
public final double[] recentTps = new double[ 3 ];
public final SlackActivityAccountant slackActivityAccountant = new SlackActivityAccountant();
// Spigot end
@@ -1006,6 +1006,57 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
{
return ( avg * exp ) + ( tps * ( 1 - exp ) );
}
+
+ // Paper start - Further improve server tick loop
+ private static final long SEC_IN_NANO = 1000000000;
+ private static final long MAX_CATCHUP_BUFFER = TICK_TIME * TPS * 60L;
+ private long lastTick = 0;
+ private long catchupTime = 0;
+ public final RollingAverage tps1 = new RollingAverage(60);
+ public final RollingAverage tps5 = new RollingAverage(60 * 5);
+ public final RollingAverage tps15 = new RollingAverage(60 * 15);
+
+ public static class RollingAverage {
+ private final int size;
+ private long time;
+ private java.math.BigDecimal total;
+ private int index = 0;
+ private final java.math.BigDecimal[] samples;
+ private final long[] times;
+
+ RollingAverage(int size) {
+ this.size = size;
+ this.time = size * SEC_IN_NANO;
+ this.total = dec(TPS).multiply(dec(SEC_IN_NANO)).multiply(dec(size));
+ this.samples = new java.math.BigDecimal[size];
+ this.times = new long[size];
+ for (int i = 0; i < size; i++) {
+ this.samples[i] = dec(TPS);
+ this.times[i] = SEC_IN_NANO;
+ }
+ }
+
+ private static java.math.BigDecimal dec(long t) {
+ return new java.math.BigDecimal(t);
+ }
+ public void add(java.math.BigDecimal x, long t) {
+ time -= times[index];
+ total = total.subtract(samples[index].multiply(dec(times[index])));
+ samples[index] = x;
+ times[index] = t;
+ time += t;
+ total = total.add(x.multiply(dec(t)));
+ if (++index == size) {
+ index = 0;
+ }
+ }
+
+ public double getAverage() {
+ return total.divide(dec(time), 30, java.math.RoundingMode.HALF_UP).doubleValue();
+ }
+ }
+ private static final java.math.BigDecimal TPS_BASE = new java.math.BigDecimal(1E9).multiply(new java.math.BigDecimal(SAMPLE_INTERVAL));
+ // Paper End
// Spigot End
protected void runServer() {
@@ -1018,26 +1069,33 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
// Spigot start
Arrays.fill( recentTps, 20 );
- long curTime, tickSection = Util.getMillis(), tickCount = 1;
+ long start = System.nanoTime(), curTime, tickSection = start; // Paper - Further improve server tick loop
+ lastTick = start - TICK_TIME; // Paper
while (this.running) {
- long i = (curTime = Util.getMillis()) - this.nextTickTime;
+ long i = ((curTime = System.nanoTime()) / (1000L * 1000L)) - this.nextTickTime; // Paper
if (i > 5000L && this.nextTickTime - this.lastOverloadWarning >= 30000L) { // CraftBukkit
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);
+ 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;
}
++MinecraftServer.currentTickLong; // Paper
- if ( tickCount++ % MinecraftServer.SAMPLE_INTERVAL == 0 )
+ if ( ++MinecraftServer.currentTick % MinecraftServer.SAMPLE_INTERVAL == 0 )
{
- double currentTps = 1E3 / ( curTime - tickSection ) * MinecraftServer.SAMPLE_INTERVAL;
- this.recentTps[0] = MinecraftServer.calcTps( this.recentTps[0], 0.92, currentTps ); // 1/exp(5sec/1min)
- this.recentTps[1] = MinecraftServer.calcTps( this.recentTps[1], 0.9835, currentTps ); // 1/exp(5sec/5min)
- this.recentTps[2] = MinecraftServer.calcTps( this.recentTps[2], 0.9945, currentTps ); // 1/exp(5sec/15min)
+ final long diff = curTime - tickSection;
+ java.math.BigDecimal currentTps = TPS_BASE.divide(new java.math.BigDecimal(diff), 30, java.math.RoundingMode.HALF_UP);
+ tps1.add(currentTps, diff);
+ tps5.add(currentTps, diff);
+ tps15.add(currentTps, diff);
+ // Backwards compat with bad plugins
+ this.recentTps[0] = tps1.getAverage();
+ this.recentTps[1] = tps5.getAverage();
+ this.recentTps[2] = tps15.getAverage();
+ // Paper end
tickSection = curTime;
}
// Spigot end
@@ -1047,7 +1105,8 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
this.debugCommandProfiler = new MinecraftServer.TimeProfiler(Util.getNanos(), this.tickCount);
}
- MinecraftServer.currentTick = (int) (System.currentTimeMillis() / 50); // CraftBukkit
+ //MinecraftServer.currentTick = (int) (System.currentTimeMillis() / 50); // CraftBukkit // Paper - don't overwrite current tick time
+ lastTick = curTime;
this.nextTickTime += 50L;
this.startMetricsRecordingTick();
this.profiler.push("tick");
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
index fca1032a38684191655282fb0815f3988b48da4b..a1735f595930b382b4339f26b5fff34114a1ed98 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -2264,6 +2264,17 @@ public final class CraftServer implements Server {
return CraftMagicNumbers.INSTANCE;
}
+ // Paper - Add getTPS API - Further improve tick loop
+ @Override
+ public double[] getTPS() {
+ return new double[] {
+ net.minecraft.server.MinecraftServer.getServer().tps1.getAverage(),
+ net.minecraft.server.MinecraftServer.getServer().tps5.getAverage(),
+ net.minecraft.server.MinecraftServer.getServer().tps15.getAverage()
+ };
+ }
+ // Paper end
+
// Spigot start
private final org.bukkit.Server.Spigot spigot = new org.bukkit.Server.Spigot()
{
diff --git a/src/main/java/org/spigotmc/TicksPerSecondCommand.java b/src/main/java/org/spigotmc/TicksPerSecondCommand.java
index 4ab81a99f906e3f28e026d0e50b5b943c1bdcfb5..9bede6a26c08ede063c7a38f1149c811df14b258 100644
--- a/src/main/java/org/spigotmc/TicksPerSecondCommand.java
+++ b/src/main/java/org/spigotmc/TicksPerSecondCommand.java
@@ -24,22 +24,30 @@ public class TicksPerSecondCommand extends Command
return true;
}
- StringBuilder sb = new StringBuilder( ChatColor.GOLD + "TPS from last 1m, 5m, 15m: " );
- for ( double tps : MinecraftServer.getServer().recentTps )
- {
- sb.append( this.format( tps ) );
- sb.append( ", " );
+ // Paper start - Further improve tick handling
+ double[] tps = org.bukkit.Bukkit.getTPS();
+ String[] tpsAvg = new String[tps.length];
+
+ for ( int i = 0; i < tps.length; i++) {
+ tpsAvg[i] = TicksPerSecondCommand.format( tps[i] );
+ }
+ sender.sendMessage(ChatColor.GOLD + "TPS from last 1m, 5m, 15m: " + org.apache.commons.lang.StringUtils.join(tpsAvg, ", "));
+ if (args.length > 0 && args[0].equals("mem") && sender.hasPermission("bukkit.command.tpsmemory")) {
+ sender.sendMessage(ChatColor.GOLD + "Current Memory Usage: " + ChatColor.GREEN + ((Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory()) / (1024 * 1024)) + "/" + (Runtime.getRuntime().totalMemory() / (1024 * 1024)) + " mb (Max: " + (Runtime.getRuntime().maxMemory() / (1024 * 1024)) + " mb)");
+ if (!hasShownMemoryWarning) {
+ sender.sendMessage(ChatColor.RED + "Warning: " + ChatColor.GOLD + " Memory usage on modern garbage collectors is not a stable value and it is perfectly normal to see it reach max. Please do not pay it much attention.");
+ hasShownMemoryWarning = true;
+ }
}
- sender.sendMessage( sb.substring( 0, sb.length() - 2 ) );
- sender.sendMessage(ChatColor.GOLD + "Current Memory Usage: " + ChatColor.GREEN + ((Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory()) / (1024 * 1024)) + "/" + (Runtime.getRuntime().totalMemory() / (1024 * 1024)) + " mb (Max: "
- + (Runtime.getRuntime().maxMemory() / (1024 * 1024)) + " mb)");
+ // Paper end
return true;
}
- private String format(double tps)
+ private boolean hasShownMemoryWarning; // Paper
+ private static String format(double tps) // Paper - Made static
{
return ( ( tps > 18.0 ) ? ChatColor.GREEN : ( tps > 16.0 ) ? ChatColor.YELLOW : ChatColor.RED ).toString()
- + ( ( tps > 20.0 ) ? "*" : "" ) + Math.min( Math.round( tps * 100.0 ) / 100.0, 20.0 );
+ + ( ( tps > 21.0 ) ? "*" : "" ) + Math.min( Math.round( tps * 100.0 ) / 100.0, 20.0 ); // Paper - only print * at 21, we commonly peak to 20.02 as the tick sleep is not accurate enough, stop the noise
}
}