Merge pull request #1927 from newrelic/async-handler-wrapper-vertx

Add null checks to vertx 4.5.1 instrumentation

Author: kanderson250

instrumentation/vertx-core-4.5.1/src/main/java/com/nr/vertx/instrumentation/AsyncHandlerWrapper.java

@@ -28,8 +28,9 @@ public void handle(AsyncResult<T> event) {
             token.linkAndExpire();
             token = null;
         }
-
-        this.original.handle(event);
-        this.original = null;
+        if (this.original != null) {
+            this.original.handle(event);
+            this.original = null;
+        }
     }
 }

instrumentation/vertx-core-4.5.1/src/main/java/io/vertx/core/impl/ContextImpl_Instrumentation.java

@@ -30,9 +30,11 @@ static <T> Future<T> executeBlocking(ContextInternal context, Handler<Promise<T>
     }
 
     static <T> void setResultHandler(ContextInternal ctx, Future<T> fut, Handler<AsyncResult<T>> resultHandler) {
-        Transaction txn = AgentBridge.getAgent().getTransaction(false);
-        if (txn != null) {
-            resultHandler = new AsyncHandlerWrapper<>(resultHandler, NewRelic.getAgent().getTransaction().getToken());
+        if (resultHandler != null){
+            Transaction txn = AgentBridge.getAgent().getTransaction(false);
+            if (txn != null) {
+                resultHandler = new AsyncHandlerWrapper<>(resultHandler, NewRelic.getAgent().getTransaction().getToken());
+            }
         }
         Weaver.callOriginal();
     }

instrumentation/vertx-core-4.5.1/src/test/java/com/nr/vertx/instrumentation/VertxBlockingTest.java

@@ -43,9 +43,24 @@ public void executeBlocking_withPromiseAndResult() throws InterruptedException {
             vertx.close();
         }
     }
+    @Test
+    public void executeBlocking_nullResultHandler() throws InterruptedException {
+        //Vertx allows resultHandler to be null.
+        Vertx vertx = Vertx.vertx();
+        executeBlocking_nullHandler(vertx);
+        String expectedTxnName = "OtherTransaction/Custom/com.nr.vertx.instrumentation.VertxBlockingTest/executeBlocking_nullHandler";
+        Introspector introspector = InstrumentationTestRunner.getIntrospector();
+        assertEquals(1, introspector.getFinishedTransactionCount(500));
+        assertEquals(1, introspector.getTransactionEvents(expectedTxnName).size());
+        for (TransactionEvent txnEvent: introspector.getTransactionEvents(expectedTxnName)) {
+            Map<String, Object> attributes = txnEvent.getAttributes();
+            assertTrue(attributes.containsKey("InFuture"));
+        }
+        vertx.close();
+    }
 
     @Trace(dispatcher = true)
-    void executeBlocking(Vertx vertx) throws InterruptedException {
+    void executeBlocking(Vertx vertx) throws InterruptedException{
         final CountDownLatch countDownLatch = new CountDownLatch(1);
         vertx.executeBlocking(future -> {
             NewRelic.addCustomParameter("InFuture", "yes");
@@ -56,4 +71,16 @@ void executeBlocking(Vertx vertx) throws InterruptedException {
         });
         countDownLatch.await();
     }
+
+    @Trace(dispatcher = true)
+    void executeBlocking_nullHandler(Vertx vertx) throws InterruptedException {
+        vertx.executeBlocking(future -> {
+            NewRelic.addCustomParameter("InFuture", "yes");
+            future.complete();
+        }, null);
+        //give the call to executeBlocking time to complete
+        Thread.sleep(500);
+    }
+
+
 }