From 09d0cf1441653dc95d7c84938c997484cce97a9a Mon Sep 17 00:00:00 2001
From: emilyy-dev <35617540+emilyy-dev@users.noreply.github.com>
Date: Sun, 28 Nov 2021 20:06:50 -0300
Subject: [PATCH] synchronized entrySet/values creation

---
 .../adventure/text/format/DecorationMap.java   | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/api/src/main/java/net/kyori/adventure/text/format/DecorationMap.java b/api/src/main/java/net/kyori/adventure/text/format/DecorationMap.java
index ed0b9de6d6..81fa8ae2c7 100644
--- a/api/src/main/java/net/kyori/adventure/text/format/DecorationMap.java
+++ b/api/src/main/java/net/kyori/adventure/text/format/DecorationMap.java
@@ -89,8 +89,8 @@ private static int offset(final TextDecoration decoration) {
   private final int bitSet;
 
   // lazy
-  private EntrySet entrySet = null;
-  private Values values = null;
+  private volatile EntrySet entrySet = null;
+  private volatile Values values = null;
 
   private DecorationMap(final int bitSet) {
     this.bitSet = bitSet;
@@ -139,7 +139,12 @@ public boolean isEmpty() {
   @Override
   public @NotNull Set<Entry<TextDecoration, TextDecoration.State>> entrySet() {
     if (this.entrySet == null) {
-      this.entrySet = new EntrySet();
+      synchronized (this) {
+        // re-check for lost race condition
+        if (this.entrySet == null) {
+          this.entrySet = new EntrySet();
+        }
+      }
     }
     return this.entrySet;
   }
@@ -152,7 +157,12 @@ public boolean isEmpty() {
   @Override
   public @NotNull Collection<TextDecoration.State> values() {
     if (this.values == null) {
-      this.values = new Values();
+      synchronized (this) {
+        // re-check for lost race condition
+        if (this.values == null) {
+          this.values = new Values();
+        }
+      }
     }
     return this.values;
   }