From 478f246490de6a546da2442df68aa08f39d774f8 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Mon, 16 May 2016 21:14:28 -0400
Subject: [PATCH] Optimize UserCache / Thread Safe

Because Techable keeps complaining about how this isn't thread safe,
easier to do this than replace the entire thing.

Additionally, move Saving of the User cache to be done async, incase
the user never changed the default setting for Spigot's save on stop only.
---
 .../Optimize-UserCache-Thread-Safe.patch      | 98 +++++++++++++++++++
 1 file changed, 98 insertions(+)
 create mode 100644 Spigot-Server-Patches/Optimize-UserCache-Thread-Safe.patch

diff --git a/Spigot-Server-Patches/Optimize-UserCache-Thread-Safe.patch b/Spigot-Server-Patches/Optimize-UserCache-Thread-Safe.patch
new file mode 100644
index 0000000000..f7b0f3821e
--- /dev/null
+++ b/Spigot-Server-Patches/Optimize-UserCache-Thread-Safe.patch
@@ -0,0 +1,98 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Aikar <aikar@aikar.co>
+Date: Mon, 16 May 2016 20:47:41 -0400
+Subject: [PATCH] Optimize UserCache / Thread Safe
+
+Because Techable keeps complaining about how this isn't thread safe,
+easier to do this than replace the entire thing.
+
+Additionally, move Saving of the User cache to be done async, incase
+the user never changed the default setting for Spigot's save on stop only.
+
+diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/server/MinecraftServer.java
++++ b/src/main/java/net/minecraft/server/MinecraftServer.java
+@@ -0,0 +0,0 @@ public abstract class MinecraftServer implements Runnable, ICommandListener, IAs
+         // Spigot start
+         if (org.spigotmc.SpigotConfig.saveUserCacheOnStopOnly) {
+             LOGGER.info("Saving usercache.json");
+-            this.X.c();
++            this.X.c(false); // Paper
+         }
+         // Spigot end
+     }
+diff --git a/src/main/java/net/minecraft/server/UserCache.java b/src/main/java/net/minecraft/server/UserCache.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/server/UserCache.java
++++ b/src/main/java/net/minecraft/server/UserCache.java
+@@ -0,0 +0,0 @@ public class UserCache {
+         this.a(gameprofile, (Date) null);
+     }
+ 
+-    private void a(GameProfile gameprofile, Date date) {
++    private synchronized void a(GameProfile gameprofile, Date date) { // Paper - synchronize
+         UUID uuid = gameprofile.getId();
+ 
+         if (date == null) {
+@@ -0,0 +0,0 @@ public class UserCache {
+         String s = gameprofile.getName().toLowerCase(Locale.ROOT);
+         UserCache.UserCacheEntry usercache_usercacheentry = new UserCache.UserCacheEntry(gameprofile, date, null);
+ 
+-        if (this.e.containsKey(uuid)) {
++        //if (this.e.containsKey(uuid)) { // Paper
+             UserCache.UserCacheEntry usercache_usercacheentry1 = (UserCache.UserCacheEntry) this.e.get(uuid);
++        if (usercache_usercacheentry1 != null) { // Paper
+ 
+             this.d.remove(usercache_usercacheentry1.a().getName().toLowerCase(Locale.ROOT));
+             this.f.remove(gameprofile);
+@@ -0,0 +0,0 @@ public class UserCache {
+     }
+ 
+     @Nullable
+-    public GameProfile getProfile(String s) {
++    public synchronized GameProfile getProfile(String s) { // Paper - synchronize
+         String s1 = s.toLowerCase(Locale.ROOT);
+         UserCache.UserCacheEntry usercache_usercacheentry = (UserCache.UserCacheEntry) this.d.get(s1);
+ 
+@@ -0,0 +0,0 @@ public class UserCache {
+         return usercache_usercacheentry == null ? null : usercache_usercacheentry.a();
+     }
+ 
+-    public String[] a() {
++    public synchronized String[] a() { // Paper - synchronize
+         ArrayList arraylist = Lists.newArrayList(this.d.keySet());
+ 
+         return (String[]) arraylist.toArray(new String[arraylist.size()]);
+@@ -0,0 +0,0 @@ public class UserCache {
+ 
+     }
+ 
++    // Paper start
+     public void c() {
++        c(true);
++    }
++    public void c(boolean asyncSave) {
++        // Paper end
+         String s = this.b.toJson(this.a(org.spigotmc.SpigotConfig.userCacheCap));
++        Runnable save = () -> { synchronized (this.h) { // Paper - ensure only 1 file is writing at same time by syncing to the FD
++
+         BufferedWriter bufferedwriter = null;
+ 
+         try {
+@@ -0,0 +0,0 @@ public class UserCache {
+         } finally {
+             IOUtils.closeQuietly(bufferedwriter);
+         }
++        // Paper start
++        }};
++        if (asyncSave) {
++            MCUtil.scheduleAsyncTask(save);
++        } else {
++            save.run();
++        }
++        // Paper end
+ 
+     }
+ 
+--
\ No newline at end of file