The recent changes in worker pool affected worker verticles with a re…

…gression: the named verticle worker pool is closed before undeploying the verticle which leads to have the worker verticle undeployment fail when the worker pool is used only by this verticle.

Close the worker pool after the verticle has been deployed instead of before.

src/main/java/io/vertx/core/impl/DeploymentManager.java

@@ -306,9 +306,6 @@ public synchronized Future<Void> doUndeploy(ContextInternal undeployingContext)
         status = ST_UNDEPLOYING;
         return doUndeployChildren(undeployingContext).compose(v -> doUndeploy(undeployingContext));
       } else {
-        if (workerPool != null) {
-          workerPool.close();
-        }
         status = ST_UNDEPLOYED;
         List<Future<?>> undeployFutures = new ArrayList<>();
         if (parent != null) {
@@ -340,6 +337,9 @@ public synchronized Future<Void> doUndeploy(ContextInternal undeployingContext)
         Promise<Void> resolvingPromise = undeployingContext.promise();
         Future.all(undeployFutures).<Void>mapEmpty().onComplete(resolvingPromise);
         Future<Void> fut = resolvingPromise.future();
+        if (workerPool != null) {
+          fut = fut.andThen(ar -> workerPool.close());
+        }
         Handler<Void> handler = undeployHandler;
         if (handler != null) {
           undeployHandler = null;

src/test/java/io/vertx/core/NamedWorkerPoolTest.java

@@ -22,6 +22,7 @@
 import java.util.concurrent.RejectedExecutionException;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicReference;
 
 import static java.util.concurrent.TimeUnit.*;
@@ -268,7 +269,7 @@ public void start() throws Exception {
   }
 
   @Test
-  public void testDeployUsingNamedPool() throws Exception {
+  public void testDeployUsingNamedPool() {
     AtomicReference<Thread> thread = new AtomicReference<>();
     String poolName = "vert.x-" + TestUtils.randomAlphaString(10);
     Promise<Void> undeployed = Promise.promise();
@@ -292,6 +293,27 @@ public void start() {
     assertWaitUntil(() -> thread.get() != null && thread.get().getState() == Thread.State.TERMINATED);
   }
 
+  @Test
+  public void testNamedWorkerPoolShouldBeClosedAfterVerticleIsUndeployed() {
+    AtomicReference<String> threadName = new AtomicReference<>();
+    vertx.deployVerticle(new AbstractVerticle() {
+      @Override
+      public void start() {
+      }
+      @Override
+      public void stop() {
+        threadName.set(Thread.currentThread().getName());
+      }
+    }, new DeploymentOptions().setWorker(true).setWorkerPoolName("test-worker")).onComplete(onSuccess(id -> {
+      vertx.undeploy(id).onComplete(onSuccess(v -> {
+        assertNotNull(threadName.get());
+        assertTrue(threadName.get().startsWith("test-worker"));
+        testComplete();
+      }));
+    }));
+    await();
+  }
+
   @Test
   public void testDeployUsingNamedWorkerDoesNotCreateExtraEventLoop() {
     int instances = getOptions().getEventLoopPoolSize();