From d28e2e9836162bbbe0e17f3f7ef4e5f90fc4e913 Mon Sep 17 00:00:00 2001
From: md_5 <git@md-5.net>
Date: Fri, 20 Jun 2014 19:40:00 +1000
Subject: [PATCH] Prevent Unbounded IntCache Growth

Based on work by Peter Lawrey, this commit prevents unbounded growth of the integer cache and instead caps it to a value specified in the configuration (1024 by default). Should prevent thrashing, especially around world generation.

diff --git a/src/main/java/net/minecraft/server/IntCache.java b/src/main/java/net/minecraft/server/IntCache.java
index 8167fdd..95060a4 100644
--- a/src/main/java/net/minecraft/server/IntCache.java
+++ b/src/main/java/net/minecraft/server/IntCache.java
@@ -17,11 +17,11 @@ public class IntCache {
         if (i <= 256) {
             if (IntCache.b.isEmpty()) {
                 aint = new int[256];
-                IntCache.c.add(aint);
+                if (c.size() < org.spigotmc.SpigotConfig.intCacheLimit) IntCache.c.add(aint);
                 return aint;
             } else {
                 aint = (int[]) IntCache.b.remove(IntCache.b.size() - 1);
-                IntCache.c.add(aint);
+                if (c.size() < org.spigotmc.SpigotConfig.intCacheLimit) IntCache.c.add(aint);
                 return aint;
             }
         } else if (i > IntCache.a) {
@@ -29,15 +29,15 @@ public class IntCache {
             IntCache.d.clear();
             IntCache.e.clear();
             aint = new int[IntCache.a];
-            IntCache.e.add(aint);
+            if (e.size() < org.spigotmc.SpigotConfig.intCacheLimit) IntCache.e.add(aint);
             return aint;
         } else if (IntCache.d.isEmpty()) {
             aint = new int[IntCache.a];
-            IntCache.e.add(aint);
+            if (e.size() < org.spigotmc.SpigotConfig.intCacheLimit) IntCache.e.add(aint);
             return aint;
         } else {
             aint = (int[]) IntCache.d.remove(IntCache.d.size() - 1);
-            IntCache.e.add(aint);
+            if (e.size() < org.spigotmc.SpigotConfig.intCacheLimit) IntCache.e.add(aint);
             return aint;
         }
     }
diff --git a/src/main/java/org/spigotmc/SpigotConfig.java b/src/main/java/org/spigotmc/SpigotConfig.java
index 78dcb39..c5e995b 100644
--- a/src/main/java/org/spigotmc/SpigotConfig.java
+++ b/src/main/java/org/spigotmc/SpigotConfig.java
@@ -327,4 +327,10 @@ public class SpigotConfig
     {
         saveUserCacheOnStopOnly = getBoolean( "settings.save-user-cache-on-stop-only", false );
     }
+
+    public static int intCacheLimit;
+    private static void intCacheLimit()
+    {
+        intCacheLimit = getInt( "settings.int-cache-limit", 1024 );
+    }
 }
-- 
2.1.0