Paper/Spigot-Server-Patches/0068-Chunk-save-queue-improvements.patch
Aikar 18c3716c49
Current Chunk for Entity and Block Entities, counts by entity type
This enables us a fast reference to the entities current chunk instead
of having to look it up by hashmap lookups.

We also store counts by type to further enable other performance optimizations in later patches.
2018-07-04 03:58:56 -04:00

167 lines
8.0 KiB
Diff

From c137628da7ca3cdca8ef577cdb3594bff5460657 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Fri, 4 Mar 2016 18:18:37 -0600
Subject: [PATCH] Chunk save queue improvements
For some unknown reason, Minecraft is sleeping 10ms between every single chunk being saved to disk.
Under high chunk load/unload activity (lots of movement / teleporting), this causes the chunk unload queue
to build up in size.
This has multiple impacts:
1) Performance of the unload queue itself - The save thread is pretty ineffecient for how it accesses it
By letting the queue get larger, checking and popping work off the queue can get less performant.
2) Performance of chunk loading - As with #1, chunk loads also have to check this queue when loading
chunk data so that it doesn't load stale data if new data is pending write to disk.
3) Memory Usage - The entire chunk has been serialized to NBT, and now sits in this queue. This leads to
elevated memory usage, and then the objects used in the serialization sit around longer than needed,
resulting in promotion to Old Generation instead of dying young.
To optimize this, we change the entire unload queue to be a proper queue. This improves the behavior of popping
the first queued chunk off, instead of abusing iterators like Mojang was doing.
This also improves reliability of chunk saving, as the previous hack job had a race condition that could
fail to save some chunks.
Then finally, Sleeping will by default be removed, but due to known issues with 1.9, a config option was added.
But if sleeps are to remain enabled, we at least lower the sleep interval so it doesn't have as much negative impact.
diff --git a/src/main/java/com/destroystokyo/paper/PaperConfig.java b/src/main/java/com/destroystokyo/paper/PaperConfig.java
index 36689db74..3898ad8fa 100644
--- a/src/main/java/com/destroystokyo/paper/PaperConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperConfig.java
@@ -204,4 +204,10 @@ public class PaperConfig {
private static void chunkLoadThreads() {
minChunkLoadThreads = Math.min(6, getInt("settings.min-chunk-load-threads", 2)); // Keep people from doing stupid things with max of 6
}
+
+ public static boolean enableFileIOThreadSleep;
+ private static void enableFileIOThreadSleep() {
+ enableFileIOThreadSleep = getBoolean("settings.sleep-between-chunk-saves", false);
+ if (enableFileIOThreadSleep) Bukkit.getLogger().info("Enabled sleeping between chunk saves, beware of memory issues");
+ }
}
diff --git a/src/main/java/net/minecraft/server/ChunkRegionLoader.java b/src/main/java/net/minecraft/server/ChunkRegionLoader.java
index a401dec60..4c3faa201 100644
--- a/src/main/java/net/minecraft/server/ChunkRegionLoader.java
+++ b/src/main/java/net/minecraft/server/ChunkRegionLoader.java
@@ -12,6 +12,7 @@ import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.annotation.Nullable;
+import java.util.concurrent.ConcurrentLinkedQueue; // Paper
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
// Spigot start
@@ -21,6 +22,8 @@ import org.spigotmc.SupplierUtils;
public class ChunkRegionLoader implements IChunkLoader, IAsyncChunkSaver {
+ private ConcurrentLinkedQueue<QueuedChunk> queue = new ConcurrentLinkedQueue<>(); // Paper - Chunk queue improvements
+ private final Object lock = new Object(); // Paper - Chunk queue improvements
private static final Logger a = LogManager.getLogger();
private final Map<ChunkCoordIntPair, Supplier<NBTTagCompound>> b = Maps.newConcurrentMap(); // Spigot
// CraftBukkit
@@ -155,9 +158,10 @@ public class ChunkRegionLoader implements IChunkLoader, IAsyncChunkSaver {
protected void a(ChunkCoordIntPair chunkcoordintpair, Supplier<NBTTagCompound> nbttagcompound) { // Spigot
// CraftBukkit
// if (!this.c.contains(chunkcoordintpair))
- {
+ synchronized (lock) { // Paper - Chunk queue improvements
this.b.put(chunkcoordintpair, nbttagcompound);
}
+ queue.add(new QueuedChunk(chunkcoordintpair, nbttagcompound)); // Paper - Chunk queue improvements
FileIOThread.a().a(this);
}
@@ -168,8 +172,11 @@ public class ChunkRegionLoader implements IChunkLoader, IAsyncChunkSaver {
}
private synchronized boolean processSaveQueueEntry(boolean logCompletion) {
- Iterator<Map.Entry<ChunkCoordIntPair, Supplier<NBTTagCompound>>> iter = this.b.entrySet().iterator(); // Spigot
- if (!iter.hasNext()) {
+ // CraftBukkit start
+ // Paper start - Chunk queue improvements
+ QueuedChunk chunk = queue.poll();
+ if (chunk == null) {
+ // Paper - end
if (logCompletion) {
// CraftBukkit end
ChunkRegionLoader.a.info("ThreadedAnvilChunkStorage ({}): All chunks are saved", this.d.getName());
@@ -177,17 +184,13 @@ public class ChunkRegionLoader implements IChunkLoader, IAsyncChunkSaver {
return false;
} else {
- // CraftBukkit start
- Map.Entry<ChunkCoordIntPair, Supplier<NBTTagCompound>> entry = iter.next(); // Spigot
- ChunkCoordIntPair chunkcoordintpair = entry.getKey();
- Supplier<NBTTagCompound> value = entry.getValue(); // Spigot
- // CraftBukkit end
+ ChunkCoordIntPair chunkcoordintpair = chunk.coords; // Paper - Chunk queue improvements
boolean flag;
try {
// this.c.add(chunkcoordintpair);
- NBTTagCompound nbttagcompound = SupplierUtils.getIfExists(value); // Spigot
+ NBTTagCompound nbttagcompound = SupplierUtils.getIfExists(chunk.compoundSupplier); // Spigot // Paper
// CraftBukkit
if (nbttagcompound != null) {
@@ -197,10 +200,11 @@ public class ChunkRegionLoader implements IChunkLoader, IAsyncChunkSaver {
ChunkRegionLoader.a.error("Failed to save chunk", exception);
}
}
+ synchronized (lock) { if (this.b.get(chunkcoordintpair) == chunk.compoundSupplier) { this.b.remove(chunkcoordintpair); } }// Paper - This will not equal if a newer version is still pending
flag = true;
} finally {
- this.b.remove(chunkcoordintpair, value); // CraftBukkit // Spigot
+ //this.b.remove(chunkcoordintpair, value); // CraftBukkit // Spigot // Paper
}
return flag;
@@ -574,4 +578,16 @@ public class ChunkRegionLoader implements IChunkLoader, IAsyncChunkSaver {
return entity;
}
}
+
+ // Paper start - Chunk queue improvements
+ private static class QueuedChunk {
+ public ChunkCoordIntPair coords;
+ public Supplier<NBTTagCompound> compoundSupplier;
+
+ public QueuedChunk(ChunkCoordIntPair coords, Supplier<NBTTagCompound> compoundSupplier) {
+ this.coords = coords;
+ this.compoundSupplier = compoundSupplier;
+ }
+ }
+ // Paper end
}
diff --git a/src/main/java/net/minecraft/server/FileIOThread.java b/src/main/java/net/minecraft/server/FileIOThread.java
index 1d6b1874c..9ee4115be 100644
--- a/src/main/java/net/minecraft/server/FileIOThread.java
+++ b/src/main/java/net/minecraft/server/FileIOThread.java
@@ -39,11 +39,15 @@ public class FileIOThread implements Runnable {
++this.d;
}
- try {
- Thread.sleep(this.e ? 0L : 10L);
- } catch (InterruptedException interruptedexception) {
- interruptedexception.printStackTrace();
+ // Paper start - Add toggle
+ if (com.destroystokyo.paper.PaperConfig.enableFileIOThreadSleep) {
+ try {
+ Thread.sleep(this.e ? 0L : 2L);
+ } catch (InterruptedException interruptedexception) {
+ interruptedexception.printStackTrace();
+ }
}
+ // Paper end
}
if (this.b.isEmpty()) {
--
2.18.0