From 43ca13cdf2f306d5b6c5e9576731336e11189331 Mon Sep 17 00:00:00 2001
From: embeddedt <42941056+embeddedt@users.noreply.github.com>
Date: Tue, 3 Oct 2023 13:45:18 -0400
Subject: [PATCH] Attempt to free leaked BufferBuilders

---
 .../BufferBuilderMixin.java                   | 35 +++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 common/src/main/java/org/embeddedt/modernfix/common/mixin/bugfix/buffer_builder_leak/BufferBuilderMixin.java

diff --git a/common/src/main/java/org/embeddedt/modernfix/common/mixin/bugfix/buffer_builder_leak/BufferBuilderMixin.java b/common/src/main/java/org/embeddedt/modernfix/common/mixin/bugfix/buffer_builder_leak/BufferBuilderMixin.java
new file mode 100644
index 00000000..3a6e190b
--- /dev/null
+++ b/common/src/main/java/org/embeddedt/modernfix/common/mixin/bugfix/buffer_builder_leak/BufferBuilderMixin.java
@@ -0,0 +1,35 @@
+package org.embeddedt.modernfix.common.mixin.bugfix.buffer_builder_leak;
+
+import com.mojang.blaze3d.vertex.BufferBuilder;
+import org.embeddedt.modernfix.ModernFix;
+import org.lwjgl.system.MemoryUtil;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+
+import java.nio.ByteBuffer;
+
+@Mixin(BufferBuilder.class)
+public class BufferBuilderMixin {
+    @Shadow private ByteBuffer buffer;
+
+    private static final MemoryUtil.MemoryAllocator ALLOCATOR = MemoryUtil.getAllocator(false);
+    private static boolean leakReported = false;
+
+    @Override
+    protected void finalize() throws Throwable {
+        try {
+            ByteBuffer buf = buffer;
+            // can be null if a mod already tried to free the buffer
+            if(buf != null) {
+                if(!leakReported) {
+                    leakReported = true;
+                    ModernFix.LOGGER.warn("One or more BufferBuilders have been leaked, ModernFix will attempt to correct this.");
+                }
+                ALLOCATOR.free(MemoryUtil.memAddress0(buf));
+                buffer = null;
+            }
+        } finally {
+            super.finalize();
+        }
+    }
+}