Update integration test and demo for async entry

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

sentinel-core/src/test/java/com/alibaba/csp/sentinel/AsyncEntryIntegrationTest.java

@@ -175,20 +175,44 @@ public class AsyncEntryIntegrationTest {
             ContextUtil.exit();
         }
 
-        TimeUnit.SECONDS.sleep(10);
-        testTreeCorrect();
+        TimeUnit.SECONDS.sleep(15);
+
+        testInvocationTreeCorrect();
     }
 
-    private void testTreeCorrect() {
+    private void testInvocationTreeCorrect() {
         DefaultNode root = Constants.ROOT;
-        Set<Node> childListForRoot = root.getChildList();
-        // TODO: check child tree
+        DefaultNode entranceNode = shouldHasChildFor(root, contextName);
+        DefaultNode testTopNode = shouldHasChildFor(entranceNode, "test-top");
+        DefaultNode testAsyncNode = shouldHasChildFor(testTopNode, "test-async");
+        shouldHasChildFor(testTopNode, "test-sync");
+        shouldHasChildFor(testAsyncNode, "test-sync-in-async");
+        DefaultNode anotherAsyncInAsyncNode = shouldHasChildFor(testAsyncNode, "test-another-async");
+        shouldHasChildFor(anotherAsyncInAsyncNode, "test-another-in-async");
+    }
+
+    private DefaultNode shouldHasChildFor(DefaultNode root, String resourceName) {
+        Set<Node> nodeSet = root.getChildList();
+        if (nodeSet == null || nodeSet.isEmpty()) {
+            fail("Child nodes should not be empty: " + root.getId().getName());
+        }
+        for (Node node : nodeSet) {
+            if (node instanceof DefaultNode) {
+                DefaultNode dn = (DefaultNode)node;
+                if (dn.getId().getName().equals(resourceName)) {
+                    return dn;
+                }
+            }
+        }
+        fail(String.format("The given node <%s> does not have child for resource <%s>",
+            root.getId().getName(), resourceName));
+        return null;
     }
 
     @After
     public void shutdown() {
         pool.shutdownNow();
-        ContextUtil.exit();
+        ContextTestUtil.cleanUpContext();
     }
 
     private void runAsync(Runnable f) {

sentinel-demo/sentinel-demo-basic/src/main/java/com/alibaba/csp/sentinel/demo/AsyncEntryDemo.java

@@ -58,7 +58,9 @@ public class AsyncEntryDemo {
                 ContextUtil.runOnContext(entry.getAsyncContext(), () -> {
                     try {
                         TimeUnit.SECONDS.sleep(2);
+                        // Normal entry nested in asynchronous entry.
                         anotherSyncInAsync();
+
                         System.out.println("Async result: 666");
                     } catch (InterruptedException e) {
                         // Ignore.
@@ -115,12 +117,10 @@ public class AsyncEntryDemo {
         try {
             final AsyncEntry entry = SphU.asyncEntry("test-async-not-nested");
 
-            CompletableFuture.runAsync(() -> {
+            this.invoke("abc", result -> {
                 // If no nested entry later, we don't have to wrap in `ContextUtil.runOnContext()`.
                 try {
-                    TimeUnit.SECONDS.sleep(1);
-                } catch (InterruptedException ex) {
-                    // Ignore.
+                    // Here to handle the async result (without other entry).
                 } finally {
                     // Exit the async entry.
                     entry.exit();
@@ -138,7 +138,7 @@ public class AsyncEntryDemo {
             final AsyncEntry entry = SphU.asyncEntry("test-async");
             this.invoke("abc", resp -> {
                 // The thread is different from original caller thread for async entry.
-                // So we need to wrap in the async context so that nested sync invocation entry
+                // So we need to wrap in the async context so that nested invocation entry
                 // can be linked to the parent asynchronous entry.
                 ContextUtil.runOnContext(entry.getAsyncContext(), () -> {
                     try {
@@ -149,7 +149,7 @@ public class AsyncEntryDemo {
 
                         System.out.println(resp);
 
-                        // Then we do a sync entry under current async context.
+                        // Then we do a sync (normal) entry under current async context.
                         fetchSyncInAsync();
                     } finally {
                         // Exit the async entry.
@@ -165,7 +165,7 @@ public class AsyncEntryDemo {
         }
     }
 
-    public static void main(String[] args) {
+    public static void main(String[] args) throws Exception {
         initFlowRule();
 
         AsyncEntryDemo service = new AsyncEntryDemo();
@@ -195,6 +195,8 @@ public class AsyncEntryDemo {
             }
             ContextUtil.exit();
         }
+
+        TimeUnit.SECONDS.sleep(20);
     }
 
     private static void initFlowRule() {