Github user zentol commented on a diff in the pull request:
https://github.com/apache/flink/pull/5645#discussion_r172508524
--- Diff:
flink-core/src/main/java/org/apache/flink/api/java/typeutils/runtime/kryo/KryoSerializer.java
---
@@ -502,6 +572,22 @@ private void readObject(ObjectInputStream in) throws
IOException, ClassNotFoundE
// For testing
//
--------------------------------------------------------------------------------------------
+ private void enterExclusiveThread() {
+ // we use simple get, check, set here, rather than CAS
+ // we don't need lock-style correctness, this is only a
sanity-check and we thus
+ // favor speed at the cost of some false negatives in this check
+ Thread previous = currentThread;
+ if (previous == null) {
+ currentThread = Thread.currentThread();
+ } else {
+ throw new IllegalStateException("Serializer already
accessed by thread " + previous.getName());
--- End diff --
We can also print the current thread for debugging purposes.
---
