KAFKA-17162: join() started thread in DefaultTaskManagerTest (#18570)

Reviewers: Lucas Brutschy <[email protected]>

Author: mjsax

streams/src/test/java/org/apache/kafka/streams/processor/internals/tasks/DefaultTaskManagerTest.java

@@ -137,6 +137,7 @@ public void shouldBlockOnAwait() throws InterruptedException {
         assertFalse(awaitingRunnable.awaitDone.await(100, TimeUnit.MILLISECONDS));
 
         awaitingRunnable.shutdown();
+        awaitingThread.join();
     }
 
     @Test
@@ -151,6 +152,7 @@ public void shouldReturnFromAwaitOnInterruption() throws InterruptedException {
         assertTrue(awaitingRunnable.awaitDone.await(VERIFICATION_TIMEOUT, TimeUnit.MILLISECONDS));
 
         awaitingRunnable.shutdown();
+        awaitingThread.join();
     }
 
     @Test
@@ -165,6 +167,7 @@ public void shouldReturnFromAwaitOnSignalProcessableTasks() throws InterruptedEx
         assertTrue(awaitingRunnable.awaitDone.await(VERIFICATION_TIMEOUT, TimeUnit.MILLISECONDS));
 
         awaitingRunnable.shutdown();
+        awaitingThread.join();
     }
 
     @Test
@@ -184,6 +187,7 @@ public void shouldReturnFromAwaitOnUnassignment() throws InterruptedException {
         assertTrue(awaitingRunnable.awaitDone.await(VERIFICATION_TIMEOUT, TimeUnit.MILLISECONDS));
 
         awaitingRunnable.shutdown();
+        awaitingThread.join();
     }
 
     @Test
@@ -198,6 +202,7 @@ public void shouldReturnFromAwaitOnAdding() throws InterruptedException {
         assertTrue(awaitingRunnable.awaitDone.await(VERIFICATION_TIMEOUT, TimeUnit.MILLISECONDS));
 
         awaitingRunnable.shutdown();
+        awaitingThread.join();
     }
 
     @Test
@@ -214,6 +219,7 @@ public void shouldReturnFromAwaitOnUnlocking() throws InterruptedException {
         assertTrue(awaitingRunnable.awaitDone.await(VERIFICATION_TIMEOUT, TimeUnit.MILLISECONDS));
 
         awaitingRunnable.shutdown();
+        awaitingThread.join();
     }
 
     @Test