(avro) branch main updated: AVRO-3987 replace synchronized with immutable replacement approach (#2900)

[opwvhk]

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opwvhk pushed a commit to branch main
in repository https://gitbox.apache.org/repos/asf/avro.git


The following commit(s) were added to refs/heads/main by this push:
     new e932c9453 AVRO-3987 replace synchronized with immutable replacement 
approach (#2900)
e932c9453 is described below

commit e932c9453be7b36e8874fe92edb3710beef4e47c
Author: Ashley Taylor <7232476+ashley-tay...@users.noreply.github.com>
AuthorDate: Sat Jun 1 03:52:55 2024 +1200

    AVRO-3987 replace synchronized with immutable replacement approach (#2900)
---
 .../src/main/java/org/apache/avro/reflect/ReflectData.java     | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git 
a/lang/java/avro/src/main/java/org/apache/avro/reflect/ReflectData.java 
b/lang/java/avro/src/main/java/org/apache/avro/reflect/ReflectData.java
index 347490679..24173b9b2 100644
--- a/lang/java/avro/src/main/java/org/apache/avro/reflect/ReflectData.java
+++ b/lang/java/avro/src/main/java/org/apache/avro/reflect/ReflectData.java
@@ -360,8 +360,8 @@ public class ReflectData extends SpecificData {
   static class ClassAccessorData {
     private final Class<?> clazz;
     private final Map<String, FieldAccessor> byName = new HashMap<>();
-    // getAccessorsFor is already synchronized, no need to wrap
-    final Map<Schema, FieldAccessor[]> bySchema = new WeakHashMap<>();
+    // getAccessorsFor replaces this map with each modification
+    volatile Map<Schema, FieldAccessor[]> bySchema = new WeakHashMap<>();
 
     private ClassAccessorData(Class<?> c) {
       clazz = c;
@@ -379,12 +379,14 @@ public class ReflectData extends SpecificData {
      * Return the field accessors as an array, indexed by the field index of 
the
      * given schema.
      */
-    private synchronized FieldAccessor[] getAccessorsFor(Schema schema) {
-      // if synchronized is removed from this method, adjust bySchema 
appropriately
+    private FieldAccessor[] getAccessorsFor(Schema schema) {
+      // to avoid synchronization, we replace the map for each modification
       FieldAccessor[] result = bySchema.get(schema);
       if (result == null) {
         result = createAccessorsFor(schema);
+        Map<Schema, FieldAccessor[]> bySchema = new 
WeakHashMap<>(this.bySchema);
         bySchema.put(schema, result);
+        this.bySchema = bySchema;
       }
       return result;
     }