PaperMC/paper-server/patches/sources/net/minecraft/util/TickThrottler.java.patch

--- a/net/minecraft/util/TickThrottler.java
+++ b/net/minecraft/util/TickThrottler.java
@@ -1,10 +1,14 @@
 package net.minecraft.util;
 
+// CraftBukkit start
+import java.util.concurrent.atomic.AtomicInteger;
+// CraftBukkit end
+
 public class TickThrottler {
 
     private final int incrementStep;
     private final int threshold;
-    private int count;
+    private final AtomicInteger count = new AtomicInteger(); // CraftBukkit - multithreaded field
 
     public TickThrottler(int increment, int threshold) {
         this.incrementStep = increment;
@@ -12,17 +16,32 @@
     }
 
     public void increment() {
-        this.count += this.incrementStep;
+        this.count.addAndGet(this.incrementStep); // CraftBukkit - use thread-safe field access instead
     }
 
     public void tick() {
+        // CraftBukkit start
+        for (int val; (val = this.count.get()) > 0 && !this.count.compareAndSet(val, val - 1); ) ;
+        /* Use thread-safe field access instead
         if (this.count > 0) {
             --this.count;
         }
+        */
+        // CraftBukkit end
 
     }
 
     public boolean isUnderThreshold() {
-        return this.count < this.threshold;
+        // CraftBukkit start - use thread-safe field access instead
+        return this.count.get() < this.threshold;
     }
+
+    public boolean isIncrementAndUnderThreshold() {
+        return this.isIncrementAndUnderThreshold(this.incrementStep, this.threshold);
+    }
+
+    public boolean isIncrementAndUnderThreshold(int incrementStep, int threshold) {
+        return this.count.addAndGet(incrementStep) < threshold;
+        // CraftBukkit end
+    }
 }