Paper/Spigot-Server-Patches/0123-Delay-Chunk-Unloads-based-on-Player-Movement.patch
Aikar 9dc4d6448b
Numerous fixes to entity related changes
While it wasn't really "broken" before, if plugins use NMS
(which they really should't be) and mess with entity management
themselves, and get it wrong, they could ultimately corrupt our
state expectations.

I've been unable to reproduce any issues locally, but these changes
are the result of me analyzing the code pretty deeply and seeing
about how to make it more durable to abnormal usage.

Any servers seeing oddities, please run with -Ddebug.entities=true
and send me any logs triggered.
2019-04-05 23:08:45 -04:00

225 lines
10 KiB
Diff

From 2fbf2c556d7840198741959940696a14c7e3c26a Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Sat, 18 Jun 2016 23:22:12 -0400
Subject: [PATCH] Delay Chunk Unloads based on Player Movement
When players are moving in the world, doing things such as building or exploring,
they will commonly go back and forth in a small area. This causes a ton of chunk load
and unload activity on the edge chunks of their view distance.
A simple back and forth movement in 6 blocks could spam a chunk to thrash a
loading and unload cycle over and over again.
This is very wasteful. This system introduces a delay of inactivity on a chunk
before it actually unloads, which is maintained separately from ChunkGC.
This allows servers with smaller worlds who do less long distance exploring to stop
wasting cpu cycles on saving/unloading/reloading chunks repeatedly.
This also makes the Chunk GC System useless, by auto scheduling unload as soon as
a spare chunk is added to the server thats outside of view distance.
diff --git a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
index bcc2ecaa3a..c70771614d 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -310,4 +310,18 @@ public class PaperWorldConfig {
preventTntFromMovingInWater = getBoolean("prevent-tnt-from-moving-in-water", false);
log("Prevent TNT from moving in water: " + preventTntFromMovingInWater);
}
+
+ public long delayChunkUnloadsBy;
+ private void delayChunkUnloadsBy() {
+ delayChunkUnloadsBy = PaperConfig.getSeconds(getString("delay-chunk-unloads-by", "10s"));
+ if (delayChunkUnloadsBy > 0) {
+ log("Delaying chunk unloads by " + delayChunkUnloadsBy + " seconds");
+ delayChunkUnloadsBy *= 1000;
+ }
+ }
+
+ public boolean skipEntityTickingInChunksScheduledForUnload = true;
+ private void skipEntityTickingInChunksScheduledForUnload() {
+ skipEntityTickingInChunksScheduledForUnload = getBoolean("skip-entity-ticking-in-chunks-scheduled-for-unload", skipEntityTickingInChunksScheduledForUnload);
+ }
}
diff --git a/src/main/java/net/minecraft/server/Chunk.java b/src/main/java/net/minecraft/server/Chunk.java
index c74176daa5..bdf922db50 100644
--- a/src/main/java/net/minecraft/server/Chunk.java
+++ b/src/main/java/net/minecraft/server/Chunk.java
@@ -40,6 +40,7 @@ public class Chunk implements IChunkAccess {
private boolean i;public boolean isLoaded() { return i; } // Paper - OBFHELPER
public final World world;
public final Map<HeightMap.Type, HeightMap> heightMap;
+ public Long scheduledForUnload; // Paper - delay chunk unloads
public final int locX;
public final int locZ;
private boolean l;
diff --git a/src/main/java/net/minecraft/server/ChunkMap.java b/src/main/java/net/minecraft/server/ChunkMap.java
index 8b3738c8f7..2021c0d02e 100644
--- a/src/main/java/net/minecraft/server/ChunkMap.java
+++ b/src/main/java/net/minecraft/server/ChunkMap.java
@@ -48,6 +48,15 @@ public class ChunkMap extends Long2ObjectOpenHashMap<Chunk> {
}
}
}
+ // Paper start - if this is a spare chunk (not part of any players view distance), go ahead and queue it for unload.
+ if (!((WorldServer)chunk.world).getPlayerChunkMap().isChunkInUse(chunk.locX, chunk.locZ)) {
+ if (chunk.world.paperConfig.delayChunkUnloadsBy > 0) {
+ chunk.scheduledForUnload = System.currentTimeMillis();
+ } else {
+ ((WorldServer) chunk.world).getChunkProvider().unload(chunk);
+ }
+ }
+ // Paper end
chunk.world.timings.syncChunkLoadPostTimer.stopTiming(); // Paper
// CraftBukkit end
diff --git a/src/main/java/net/minecraft/server/ChunkProviderServer.java b/src/main/java/net/minecraft/server/ChunkProviderServer.java
index c54df45837..d0bf0f72da 100644
--- a/src/main/java/net/minecraft/server/ChunkProviderServer.java
+++ b/src/main/java/net/minecraft/server/ChunkProviderServer.java
@@ -307,6 +307,19 @@ public class ChunkProviderServer implements IChunkProvider {
}
activityAccountant.endActivity(); // Spigot
}
+ // Paper start - delayed chunk unloads
+ long now = System.currentTimeMillis();
+ long unloadAfter = world.paperConfig.delayChunkUnloadsBy;
+ if (unloadAfter > 0) {
+ //noinspection Convert2streamapi
+ for (Chunk chunk : chunks.values()) {
+ if (chunk.scheduledForUnload != null && now - chunk.scheduledForUnload > unloadAfter) {
+ chunk.scheduledForUnload = null;
+ unload(chunk);
+ }
+ }
+ }
+ // Paper end
this.chunkScheduler.a(booleansupplier);
}
diff --git a/src/main/java/net/minecraft/server/PlayerChunk.java b/src/main/java/net/minecraft/server/PlayerChunk.java
index e47aae2f8b..b9d90c4fb8 100644
--- a/src/main/java/net/minecraft/server/PlayerChunk.java
+++ b/src/main/java/net/minecraft/server/PlayerChunk.java
@@ -29,8 +29,23 @@ public class PlayerChunk {
chunkproviderserver.a(i, j);
this.chunk = chunkproviderserver.getChunkAt(i, j, true, false);
+ markChunkUsed(); // Paper - delay chunk unloads
}
+ // Paper start
+ private void markChunkUsed() {
+ if (chunk == null) {
+ return;
+ }
+ if (chunkHasPlayers) {
+ chunk.scheduledForUnload = null;
+ } else if (chunk.scheduledForUnload == null) {
+ chunk.scheduledForUnload = System.currentTimeMillis();
+ }
+ }
+ private boolean chunkHasPlayers = false;
+ // Paper end
+
public ChunkCoordIntPair a() {
return this.location;
}
@@ -41,6 +56,8 @@ public class PlayerChunk {
} else {
if (this.players.isEmpty()) {
this.i = this.playerChunkMap.getWorld().getTime();
+ chunkHasPlayers = true; // Paper - delay chunk unloads
+ markChunkUsed(); // Paper - delay chunk unloads
}
this.players.add(entityplayer);
@@ -59,6 +76,8 @@ public class PlayerChunk {
this.players.remove(entityplayer);
if (this.players.isEmpty()) {
+ chunkHasPlayers = false; // Paper - delay chunk unloads
+ markChunkUsed(); // Paper - delay chunk unloads
this.playerChunkMap.b(this);
}
@@ -70,6 +89,7 @@ public class PlayerChunk {
return true;
} else {
this.chunk = this.playerChunkMap.getWorld().getChunkProvider().getChunkAt(this.location.x, this.location.z, true, flag);
+ markChunkUsed(); // Paper - delay chunk unloads
return this.chunk != null;
}
}
diff --git a/src/main/java/net/minecraft/server/PlayerChunkMap.java b/src/main/java/net/minecraft/server/PlayerChunkMap.java
index 2064576501..ab4f3b7223 100644
--- a/src/main/java/net/minecraft/server/PlayerChunkMap.java
+++ b/src/main/java/net/minecraft/server/PlayerChunkMap.java
@@ -452,7 +452,13 @@ public class PlayerChunkMap {
Chunk chunk = playerchunk.f();
if (chunk != null) {
- this.getWorld().getChunkProvider().unload(chunk);
+ // Paper start - delay chunk unloads
+ if (world.paperConfig.delayChunkUnloadsBy <= 0) {
+ this.getWorld().getChunkProvider().unload(chunk);
+ } else {
+ chunk.scheduledForUnload = System.currentTimeMillis();
+ }
+ // Paper end
}
}
diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
index 32ee298648..dcff6c8d8a 100644
--- a/src/main/java/net/minecraft/server/World.java
+++ b/src/main/java/net/minecraft/server/World.java
@@ -1293,7 +1293,13 @@ public abstract class World implements IEntityAccess, GeneratorAccess, IIBlockAc
if (!tileentity.x() && tileentity.hasWorld()) {
BlockPosition blockposition = tileentity.getPosition();
- if (this.isLoaded(blockposition) && this.K.a(blockposition)) {
+ // Paper start - Skip ticking in chunks scheduled for unload
+ net.minecraft.server.Chunk chunk = this.getChunkIfLoaded(blockposition);
+ boolean shouldTick = chunk != null;
+ if(this.paperConfig.skipEntityTickingInChunksScheduledForUnload)
+ shouldTick = shouldTick && chunk.scheduledForUnload == null;
+ if (shouldTick && this.K.a(blockposition)) {
+ // Paper end
try {
this.methodProfiler.a(() -> {
return String.valueOf(TileEntityTypes.a(tileentity.C()));
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
index a8c7e7931e..f7883e7085 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
@@ -1772,7 +1772,7 @@ public class CraftWorld implements World {
ChunkProviderServer cps = world.getChunkProvider();
for (net.minecraft.server.Chunk chunk : cps.chunks.values()) {
// If in use, skip it
- if (isChunkInUse(chunk.locX, chunk.locZ)) {
+ if (isChunkInUse(chunk.locX, chunk.locZ) || chunk.scheduledForUnload != null) { // Paper - delayed chunk unloads
continue;
}
diff --git a/src/main/java/org/spigotmc/ActivationRange.java b/src/main/java/org/spigotmc/ActivationRange.java
index d08ef3fe10..081789a8fe 100644
--- a/src/main/java/org/spigotmc/ActivationRange.java
+++ b/src/main/java/org/spigotmc/ActivationRange.java
@@ -323,6 +323,11 @@ public class ActivationRange
{
isActive = false;
}
+ // Paper start - Skip ticking in chunks scheduled for unload
+ else if (entity.world.paperConfig.skipEntityTickingInChunksScheduledForUnload && (chunk == null || chunk.scheduledForUnload != null)) {
+ isActive = false;
+ }
+ // Paper end
return isActive;
}
}
--
2.21.0