Trying to fix flaky test (#2779)

* Fix flaky test

* Increase completion wait time

* Add volatile

Author: zoewangg

services-custom/dynamodb-enhanced/src/test/java/software/amazon/awssdk/enhanced/dynamodb/functionaltests/BufferingSubscriber.java

@@ -25,8 +25,8 @@
 public class BufferingSubscriber<T> implements Subscriber<T> {
     private final CountDownLatch latch = new CountDownLatch(1);
     private final List<T> bufferedItems = new ArrayList<>();
-    private Throwable bufferedError = null;
-    private boolean isCompleted = false;
+    private volatile Throwable bufferedError = null;
+    private volatile boolean isCompleted = false;
 
     @Override
     public void onSubscribe(Subscription subscription) {

services-custom/dynamodb-enhanced/src/test/java/software/amazon/awssdk/enhanced/dynamodb/functionaltests/LocalDynamoDbAsyncTestBase.java

@@ -32,7 +32,7 @@ protected DynamoDbAsyncClient getDynamoDbAsyncClient() {
     public static <T> List<T> drainPublisher(SdkPublisher<T> publisher, int expectedNumberOfResults) {
         BufferingSubscriber<T> subscriber = new BufferingSubscriber<>();
         publisher.subscribe(subscriber);
-        subscriber.waitForCompletion(1000L);
+        subscriber.waitForCompletion(5000L);
 
         assertThat(subscriber.isCompleted(), is(true));
         assertThat(subscriber.bufferedError(), is(nullValue()));

services-custom/dynamodb-enhanced/src/test/java/software/amazon/awssdk/enhanced/dynamodb/mocktests/AsyncBatchGetItemTest.java

@@ -24,6 +24,7 @@
 import com.github.tomakehurst.wiremock.junit.WireMockRule;
 import java.net.URI;
 import java.util.List;
+import org.junit.After;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
@@ -71,6 +72,11 @@ public void setup() {
         table = enhancedClient.table("table", tableSchema);
     }
 
+    @After
+    public void cleanup() {
+        wireMock.resetAll();
+    }
+
     @Test
     public void successfulResponseWithoutUnprocessedKeys_NoNextPage() {
         stubSuccessfulResponse();