From b310708d7d0307a433020ff78db4ac31dfeb0b7a Mon Sep 17 00:00:00 2001
From: PJ Fanning <pjfanning@users.noreply.github.com>
Date: Sun, 7 Apr 2024 14:34:32 +0200
Subject: [PATCH] rework synchronized block in TypeDeserializerBase

---
 .../databind/jsontype/impl/TypeDeserializerBase.java   | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/main/java/com/fasterxml/jackson/databind/jsontype/impl/TypeDeserializerBase.java b/src/main/java/com/fasterxml/jackson/databind/jsontype/impl/TypeDeserializerBase.java
index 2af739da33..8dad89b7cf 100644
--- a/src/main/java/com/fasterxml/jackson/databind/jsontype/impl/TypeDeserializerBase.java
+++ b/src/main/java/com/fasterxml/jackson/databind/jsontype/impl/TypeDeserializerBase.java
@@ -223,13 +223,15 @@ protected final JsonDeserializer<Object> _findDefaultImplDeserializer(Deserializ
             return NullifyingDeserializer.instance;
         }
 
-        synchronized (_defaultImpl) {
-            if (_defaultImplDeserializer == null) {
-                _defaultImplDeserializer = ctxt.findContextualValueDeserializer(
+        if (_defaultImplDeserializer == null) {
+            synchronized (_defaultImpl) {
+                if (_defaultImplDeserializer == null) {
+                    _defaultImplDeserializer = ctxt.findContextualValueDeserializer(
                         _defaultImpl, _property);
+                }
             }
-            return _defaultImplDeserializer;
         }
+        return _defaultImplDeserializer;
     }
 
     /**