Use thread safe arrays too

1 files changed, 3 insertions, 3 deletions

diff --git a/jdisc_core/src/main/java/com/yahoo/jdisc/HeaderFields.java b/jdisc_core/src/main/java/com/yahoo/jdisc/HeaderFields.java
index 2f7cd59c737..fd6b22ade12 100644
--- a/jdisc_core/src/main/java/com/yahoo/jdisc/HeaderFields.java
+++ b/jdisc_core/src/main/java/com/yahoo/jdisc/HeaderFields.java
@@ -9,6 +9,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentSkipListMap;
+import java.util.concurrent.CopyOnWriteArrayList;
 
 /**
  * This is an encapsulation of the header fields that belong to either a {@link Request} or a {@link Response}. It is
@@ -140,14 +141,13 @@ public class HeaderFields implements Map<String, List<String>> {
      *         <code>key</code>.
      */
     public List<String> put(String key, String value) {
-        ArrayList<String> list = new ArrayList<String>(1);
-        list.add(value);
+        List<String> list = new CopyOnWriteArrayList<>(List.of(value));
         return content.put(key, list);
     }
 
     @Override
     public List<String> put(String key, List<String> value) {
-        return content.put(key, new ArrayList<>(value));
+        return content.put(key, new CopyOnWriteArrayList<>(value));
     }
 
     @Override