How to use

awaitBlocker

method

in

org.apache.flink.core.testutils.BlockerSync

@Before
public void setUp() throws Exception {
  jobExecuteThread = new CheckedThread() {
    @Override
    public void go() throws Exception {
      StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
      env.addSource(new SourceFunction<String>() {
        @Override
        public void run(SourceContext<String> ctx) throws Exception {
          sync.block();
        }
        @Override
        public void cancel() {
          sync.releaseBlocker();
        }
      }).addSink(new PrintSinkFunction());
      env.execute();
    }
  };
  jobExecuteThread.start();
  sync.awaitBlocker();
}

@Test
public void testConcurrentUseOfSerializer() throws Exception {
  final AvroSerializer<String> serializer = new AvroSerializer<>(String.class);
  final BlockerSync sync = new BlockerSync();
  final DataOutputView regularOut = new DataOutputSerializer(32);
  final DataOutputView lockingOut = new LockingView(sync);
  // this thread serializes and gets stuck there
  final CheckedThread thread = new CheckedThread("serializer") {
    @Override
    public void go() throws Exception {
      serializer.serialize("a value", lockingOut);
    }
  };
  thread.start();
  sync.awaitBlocker();
  // this should fail with an exception
  try {
    serializer.serialize("value", regularOut);
    fail("should have failed with an exception");
  }
  catch (IllegalStateException e) {
    // expected
  }
  finally {
    // release the thread that serializes
    sync.releaseBlocker();
  }
  // this propagates exceptions from the spawned thread
  thread.sync();
}

@Test
public void testConcurrentUseOfSerializer() throws Exception {
  final KryoSerializer<String> serializer = new KryoSerializer<>(String.class, new ExecutionConfig());
  final BlockerSync sync = new BlockerSync();
  final DataOutputView regularOut = new DataOutputSerializer(32);
  final DataOutputView lockingOut = new LockingView(sync);
  // this thread serializes and gets stuck there
  final CheckedThread thread = new CheckedThread("serializer") {
    @Override
    public void go() throws Exception {
      serializer.serialize("a value", lockingOut);
    }
  };
  thread.start();
  sync.awaitBlocker();
  // this should fail with an exception
  try {
    serializer.serialize("value", regularOut);
    fail("should have failed with an exception");
  }
  catch (IllegalStateException e) {
    // expected
  }
  finally {
    // release the thread that serializes
    sync.releaseBlocker();
  }
  // this propagates exceptions from the spawned thread
  thread.sync();
}