From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <Spottedleaf@users.noreply.github.com>
Date: Sun, 3 Mar 2019 20:53:18 -0800
Subject: [PATCH] Add TickThread

Placeholder patch, to be used by chunksystem rewrite

diff --git a/src/main/java/io/papermc/paper/util/TickThread.java b/src/main/java/io/papermc/paper/util/TickThread.java
new file mode 100644
index 0000000000000000000000000000000000000000..73e83d56a340f0c7dcb8ff737d621003e72c6de4
--- /dev/null
+++ b/src/main/java/io/papermc/paper/util/TickThread.java
@@ -0,0 +1,83 @@
+package io.papermc.paper.util;
+
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.world.entity.Entity;
+import org.bukkit.Bukkit;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public final class TickThread extends Thread {
+
+    public static final boolean STRICT_THREAD_CHECKS = Boolean.getBoolean("paper.strict-thread-checks");
+
+    static {
+        if (STRICT_THREAD_CHECKS) {
+            MinecraftServer.LOGGER.warn("Strict thread checks enabled - performance may suffer");
+        }
+    }
+
+    public static void softEnsureTickThread(final String reason) {
+        if (!STRICT_THREAD_CHECKS) {
+            return;
+        }
+        ensureTickThread(reason);
+    }
+
+    public static void ensureTickThread(final String reason) {
+        if (!isTickThread()) {
+            MinecraftServer.LOGGER.error("Thread " + Thread.currentThread().getName() + " failed main thread check: " + reason, new Throwable());
+            throw new IllegalStateException(reason);
+        }
+    }
+
+    public static void ensureTickThread(final ServerLevel world, final int chunkX, final int chunkZ, final String reason) {
+        if (!isTickThreadFor(world, chunkX, chunkZ)) {
+            MinecraftServer.LOGGER.error("Thread " + Thread.currentThread().getName() + " failed main thread check: " + reason, new Throwable());
+            throw new IllegalStateException(reason);
+        }
+    }
+
+    public static void ensureTickThread(final Entity entity, final String reason) {
+        if (!isTickThreadFor(entity)) {
+            MinecraftServer.LOGGER.error("Thread " + Thread.currentThread().getName() + " failed main thread check: " + reason, new Throwable());
+            throw new IllegalStateException(reason);
+        }
+    }
+
+    public final int id; /* We don't override getId as the spec requires that it be unique (with respect to all other threads) */
+
+    private static final AtomicInteger ID_GENERATOR = new AtomicInteger();
+
+    public TickThread(final String name) {
+        this(null, name);
+    }
+
+    public TickThread(final Runnable run, final String name) {
+        this(run, name, ID_GENERATOR.incrementAndGet());
+    }
+
+    private TickThread(final Runnable run, final String name, final int id) {
+        super(run, name);
+        this.id = id;
+    }
+
+    public static TickThread getCurrentTickThread() {
+        return (TickThread) Thread.currentThread();
+    }
+
+    public static boolean isTickThread() {
+        return Bukkit.isPrimaryThread();
+    }
+
+    public static boolean isTickThreadFor(final ServerLevel world, final int chunkX, final int chunkZ) {
+        return isTickThread();
+    }
+
+    public static boolean isTickThreadFor(final ServerLevel world, final int chunkX, final int chunkZ, final int radius) {
+        return isTickThread();
+    }
+
+    public static boolean isTickThreadFor(final Entity entity) {
+        return isTickThread();
+    }
+}
diff --git a/src/main/java/org/spigotmc/AsyncCatcher.java b/src/main/java/org/spigotmc/AsyncCatcher.java
index bbf0d9d9c44fe8d7add2f978994ec129420814c7..78669fa035b7537ff7e533cf32aaf2995625424f 100644
--- a/src/main/java/org/spigotmc/AsyncCatcher.java
+++ b/src/main/java/org/spigotmc/AsyncCatcher.java
@@ -9,7 +9,7 @@ public class AsyncCatcher
 
     public static void catchOp(String reason)
     {
-        if ( AsyncCatcher.enabled && Thread.currentThread() != MinecraftServer.getServer().serverThread )
+        if ( (AsyncCatcher.enabled || io.papermc.paper.util.TickThread.STRICT_THREAD_CHECKS) && Thread.currentThread() != MinecraftServer.getServer().serverThread ) // Paper
         {
             throw new IllegalStateException( "Asynchronous " + reason + "!" );
         }