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8ed2992da9
Portion of diff was dropped in the mappings update commit. Also remove the option to remove invalid statistics. The server will automatically do this now as of... 1.13?, our option wasn't even doing anything.
68 lines
3.0 KiB
Diff
68 lines
3.0 KiB
Diff
From 11658c58e5db3b36e30ccd8c4dfd2f9d047856bc Mon Sep 17 00:00:00 2001
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From: Aikar <aikar@aikar.co>
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Date: Mon, 23 Jul 2018 23:40:04 -0400
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Subject: [PATCH] Optimize Region File Cache
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CraftBukkit added synchronization to read and write methods. This adds
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much more contention on this object for accessing region files, as
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the entire read and write of NBT data is now a blocking operation.
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This causes issues when something then simply needs to check if a chunk exists
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on the main thread, causing a block...
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However, this synchronization was unnecessary, because there is already
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enough synchronization done to keep things safe
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1) Obtaining a Region File: Those methods are still static synchronized.
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Meaning we can safely obtain a Region File concurrently.
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2) RegionFile data access: Methods reading and manipulating data from
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a region file are also marked synchronized, ensuring that no 2 processes
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are reading or writing data at the same time.
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3) Checking a region file for chunkExists: getOffset is also synchronized
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ensuring that even if a chunk is currently being written, it will be safe.
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By removing these synchronizations, we reduce the locking to only
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when data is being write or read.
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GZIP compression and NBT Buffer creation will no longer be part of the
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synchronized context, reducing lock times.
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Ultimately: This brings us back to Vanilla, which has had no indication of region file loss.
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diff --git a/src/main/java/net/minecraft/server/RegionFileCache.java b/src/main/java/net/minecraft/server/RegionFileCache.java
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index c0ab543b9..15666325e 100644
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--- a/src/main/java/net/minecraft/server/RegionFileCache.java
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+++ b/src/main/java/net/minecraft/server/RegionFileCache.java
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@@ -99,7 +99,7 @@ public class RegionFileCache {
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@Nullable
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// CraftBukkit start - call sites hoisted for synchronization
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- public static synchronized NBTTagCompound read(File file, int i, int j) throws IOException {
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+ public static NBTTagCompound read(File file, int i, int j) throws IOException { // Paper - remove synchronization
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RegionFile regionfile = a(file, i, j);
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DataInputStream datainputstream = regionfile.a(i & 31, j & 31);
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@@ -112,7 +112,7 @@ public class RegionFileCache {
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}
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@Nullable
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- public static synchronized void write(File file, int i, int j, NBTTagCompound nbttagcompound) throws IOException {
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+ public static void write(File file, int i, int j, NBTTagCompound nbttagcompound) throws IOException {
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int attempts = 0; Exception laste = null; while (attempts++ < 5) { try { // Paper
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RegionFile regionfile = a(file, i, j);
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@@ -138,7 +138,7 @@ public class RegionFileCache {
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// Paper end
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}
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- public static synchronized boolean chunkExists(File file, int i, int j) {
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+ public static boolean chunkExists(File file, int i, int j) { // Paper - remove synchronization
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RegionFile regionfile = b(file, i, j);
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return regionfile != null ? regionfile.d(i & 31, j & 31) : false;
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--
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2.20.0
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