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Author: zhongkechen

sdk/src/main/java/software/amazon/lambda/durable/operation/ConcurrencyOperation.java

@@ -232,6 +232,8 @@ private BaseDurableOperation waitForChildCompletion(Set<BaseDurableOperation> ru
                     }
                     registerActiveThread(threadContext.threadId());
                 });
+                // <- there is a race condition if the future is completed at this point
+                // The registerActiveThread would have been called before deregisterActiveThread
                 if (!futureCompletedImmediately.get()) {
                     // Deregister the current thread to allow suspension
                     executionManager.deregisterActiveThread(threadContext.threadId());