ea855e2b46
Upstream has released updates that appears to apply and compile correctly. This update has not been tested by PaperMC and as with ANY update, please do your own testing Developers!: You will need to clean up your work/Minecraft/1.13.2 folder for this Also, restore a patch that was dropped in the last upstream Bukkit Changes: 279eeab3 Fix command description not being set 96e2bb18 Remove debug print from SyntheticEventTest CraftBukkit Changes: d3ed1516 Fix dangerously threaded beacons 217a293d Don't relocate joptsimple to allow --help to work. 1be05a21 Prepare for imminent Java 12 release a49270b2 Mappings Update 5259d80c SPIGOT-4669: Fix PlayerTeleportEvent coordinates for relative teleports Spigot Changes: e6eb36f2 Rebuild patches
67 lines
3 KiB
Diff
67 lines
3 KiB
Diff
From ef3479c926dcb3b18351f3d163558c9b1d86aa58 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 964996976..d07222239 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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2.21.0
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