835bc39b03
Updated Upstream (Bukkit/CraftBukkit/Spigot) Bukkit Changes: 2dcc44dc SPIGOT-4307: Fix hacky API for banners on shields e0fc6572 SPIGOT-4309: Add "forced" display of particles efeeab2f Add index to README.md for easier navigation f502bc6f Update to Minecraft 1.13.1 CraftBukkit Changes: d0bb0a1d Fix some tests randomly failing 997d378d Fix client stall in specific teleportation scenarios b3dc2366 SPIGOT-4307: Fix hacky API for banners on shields 2a271162 SPIGOT-4301: Fix more invalid enchants 5d0d83bb SPIGOT-4309: Add "forced" display of particles a6772578 Add additional tests for CraftBlockData ce1af0c3 Update to Minecraft 1.13.1 Spigot Changes: 2440e189 Rebuild patches 4ecffced Update to Minecraft 1.13.1
67 lines
3 KiB
Diff
67 lines
3 KiB
Diff
From c033b7ac3b55f3523700a96a450368327b68c2d9 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 c0ab543b91..15666325ea 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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2.18.0
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