From cf62349837574d353cb80cdff498d152fb337fd7 Mon Sep 17 00:00:00 2001
From: Sotr <i@omc.hk>
Date: Sat, 16 Jun 2018 20:36:18 +0800
Subject: [PATCH] Better world lock

---
 .../akarin/api/internal/mixin/IMixinLockProvider.java  |  5 +++++
 .../akarin/server/mixin/core/MixinMinecraftServer.java |  6 +++---
 .../io/akarin/server/mixin/core/MixinWorldServer.java  | 10 +++++++++-
 3 files changed, 17 insertions(+), 4 deletions(-)
 create mode 100644 sources/src/main/java/io/akarin/api/internal/mixin/IMixinLockProvider.java

diff --git a/sources/src/main/java/io/akarin/api/internal/mixin/IMixinLockProvider.java b/sources/src/main/java/io/akarin/api/internal/mixin/IMixinLockProvider.java
new file mode 100644
index 000000000..27e4ff670
--- /dev/null
+++ b/sources/src/main/java/io/akarin/api/internal/mixin/IMixinLockProvider.java
@@ -0,0 +1,5 @@
+package io.akarin.api.internal.mixin;
+
+public interface IMixinLockProvider {
+    public Object lock();
+}
\ No newline at end of file
diff --git a/sources/src/main/java/io/akarin/server/mixin/core/MixinMinecraftServer.java b/sources/src/main/java/io/akarin/server/mixin/core/MixinMinecraftServer.java
index c106c86ac..207730ff7 100644
--- a/sources/src/main/java/io/akarin/server/mixin/core/MixinMinecraftServer.java
+++ b/sources/src/main/java/io/akarin/server/mixin/core/MixinMinecraftServer.java
@@ -17,6 +17,7 @@ import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
 
 import co.aikar.timings.MinecraftTimings;
 import io.akarin.api.internal.Akari;
+import io.akarin.api.internal.mixin.IMixinLockProvider;
 import io.akarin.server.core.AkarinGlobalConfig;
 import io.akarin.server.core.AkarinSlackScheduler;
 import net.minecraft.server.CrashReport;
@@ -144,10 +145,9 @@ public abstract class MixinMinecraftServer {
         Akari.mayEnableAsyncCathcer = false;
         Akari.STAGE_TICK.submit(() -> {
             // Never tick one world concurrently!
-            // TODO better treat world index
             for (int i = 1; i <= worlds.size(); ++i) {
                 WorldServer world = worlds.get(i < worlds.size() ? i : 0);
-                synchronized (world) {
+                synchronized (((IMixinLockProvider) world).lock()) {
                     tickEntities(world);
                 }
             }
@@ -155,7 +155,7 @@ public abstract class MixinMinecraftServer {
         
         for (int i = 0; i < worlds.size(); ++i) {
             WorldServer world = worlds.get(i);
-            synchronized (world) {
+            synchronized (((IMixinLockProvider) world).lock()) {
                 tickWorld(world);
             }
         }
diff --git a/sources/src/main/java/io/akarin/server/mixin/core/MixinWorldServer.java b/sources/src/main/java/io/akarin/server/mixin/core/MixinWorldServer.java
index 20b82c46f..b1c864e61 100644
--- a/sources/src/main/java/io/akarin/server/mixin/core/MixinWorldServer.java
+++ b/sources/src/main/java/io/akarin/server/mixin/core/MixinWorldServer.java
@@ -4,13 +4,21 @@ import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.injection.At;
 import org.spongepowered.asm.mixin.injection.Redirect;
 
+import io.akarin.api.internal.mixin.IMixinLockProvider;
 import net.minecraft.server.WorldServer;
 
 @Mixin(value = WorldServer.class, remap = false)
-public abstract class MixinWorldServer {
+public abstract class MixinWorldServer implements IMixinLockProvider {
     @Redirect(method = "doTick", at = @At(
             value = "INVOKE",
             target = "net/minecraft/server/PlayerChunkMap.flush()V"
     ))
     public void onFlush() {} // Migrated to main thread
+    
+    private final Object tickLock = new Object();
+
+    @Override
+    public Object lock() {
+        return tickLock;
+    }
 }