Do full connector tracker cleanup when the session lock is released (#9707)

As there is no "request end" call after invoking UI.access() from a background thread,
the connector map was not earlier properly cleaned afterwards. If you toggled visibility of a
component from the background thread, the tracker state became inconsistent.

If this becomes a performance problem, it could probably be optimized to that cleanup
is done in request end and only at the end of access if not inside a request.

Fixes #9654

server/src/main/java/com/vaadin/server/VaadinService.java

@@ -1418,17 +1418,6 @@ public abstract class VaadinService implements Serializable {
                 final long duration = (System.nanoTime() - (Long) request
                         .getAttribute(REQUEST_START_TIME_ATTRIBUTE)) / 1000000;
                 session.setLastRequestDuration(duration);
-
-                // Check that connector tracker is in a consistent state here to
-                // avoid doing it multiple times for a single request
-                for (UI ui : session.getUIs()) {
-                    try {
-                        ui.getConnectorTracker().ensureCleanedAndConsistent();
-                    } catch (AssertionError | Exception e) {
-                        getLogger().log(Level.SEVERE,
-                                "Error cleaning ConnectionTracker", e);
-                    }
-                }
             } finally {
                 session.unlock();
             }

server/src/main/java/com/vaadin/server/VaadinSession.java

@@ -1029,7 +1029,7 @@ public class VaadinSession implements HttpSessionBindingListener, Serializable {
                     }
                     try {
                         ui.getConnectorTracker().cleanConnectorMap();
-                    } catch (Exception e) {
+                    } catch (AssertionError | Exception e) {
                         getLogger().log(Level.SEVERE,
                                 "Exception while cleaning connector map for ui "
                                         + ui.getUIId(),

server/src/main/java/com/vaadin/ui/ConnectorTracker.java

@@ -272,17 +272,7 @@ public class ConnectorTracker implements Serializable {
         }
 
         cleanStreamVariables();
-    }
 
-    /**
-     * Performs expensive checks to ensure that the connector tracker is cleaned
-     * properly and in a consistent state.
-     * <p>
-     * This should only be called by the framework.
-     *
-     * @since 8.1
-     */
-    public void ensureCleanedAndConsistent() {
         // Do this expensive check only with assertions enabled
         assert isHierarchyComplete() : "The connector hierarchy is corrupted. "
                 + "Check for missing calls to super.setParent(), super.attach() and super.detach() "
@@ -315,6 +305,10 @@ public class ConnectorTracker implements Serializable {
             } else if (!uninitializedConnectors.contains(connector)
                     && !LegacyCommunicationManager
                             .isConnectorVisibleToClient(connector)) {
+                // Connector was visible to the client but is no longer (e.g.
+                // setVisible(false) has been called or SelectiveRenderer tells
+                // it's no longer shown) -> make sure that the full state is
+                // sent again when/if made visible
                 uninitializedConnectors.add(connector);
                 diffStates.remove(connector);
                 assert isRemovalSentToClient(connector) : "Connector "

uitest/src/main/java/com/vaadin/tests/application/MissingHierarchyDetection.java

@@ -23,7 +23,7 @@ import java.util.logging.LogRecord;
 import java.util.logging.Logger;
 
 import com.vaadin.server.VaadinRequest;
-import com.vaadin.server.VaadinService;
+import com.vaadin.server.VaadinSession;
 import com.vaadin.tests.components.AbstractReindeerTestUIWithLog;
 import com.vaadin.ui.Button;
 import com.vaadin.ui.Button.ClickEvent;
@@ -60,15 +60,15 @@ public class MissingHierarchyDetection extends AbstractReindeerTestUIWithLog {
     @Override
     protected void setup(VaadinRequest request) {
         // Catch log messages so we can see if there is an error
-        Logger vaadinServiceLogger = Logger
-                .getLogger(VaadinService.class.getName());
-        vaadinServiceLogger.addHandler(new Handler() {
+        Logger vaadinSessionLogger = Logger
+                .getLogger(VaadinSession.class.getName());
+        vaadinSessionLogger.addHandler(new Handler() {
 
             @Override
             public void publish(LogRecord record) {
                 if (record.getThrown() instanceof AssertionError) {
                     pendingErrors.add(record);
-                    vaadinServiceLogger.removeHandler(this);
+                    vaadinSessionLogger.removeHandler(this);
                 }
             }
 

uitest/src/main/java/com/vaadin/tests/push/PushToggleComponentVisibility.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2000-2016 Vaadin Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.vaadin.tests.push;
+
+import com.vaadin.annotations.Push;
+import com.vaadin.annotations.Widgetset;
+import com.vaadin.server.VaadinRequest;
+import com.vaadin.ui.Button;
+import com.vaadin.ui.Label;
+import com.vaadin.ui.UI;
+import com.vaadin.ui.VerticalLayout;
+
+@Push
+@Widgetset("com.vaadin.DefaultWidgetSet")
+public class PushToggleComponentVisibility extends UI {
+
+    @Override
+    protected void init(VaadinRequest request) {
+        VerticalLayout mainLayout = new VerticalLayout();
+        setContent(mainLayout);
+
+        Label label = new Label("Please wait");
+        label.setId("label");
+        label.setVisible(false);
+        mainLayout.addComponent(label);
+
+        Button button = new Button("Hide me 3 secondes");
+        button.setId("hide");
+        button.addClickListener(event1 -> {
+            button.setVisible(false);
+            label.setVisible(true);
+
+            new Thread(() -> {
+                try {
+                    Thread.sleep(3000);
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                }
+                button.getUI().access(() -> {
+                    button.setVisible(true);
+                    label.setVisible(false);
+                    button.getUI().push();
+                });
+            }).start();
+        });
+        mainLayout.addComponent(button);
+    }
+
+}

uitest/src/test/java/com/vaadin/tests/push/PushToggleComponentVisibilityTest.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2000-2016 Vaadin Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.vaadin.tests.push;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.openqa.selenium.By;
+
+import com.vaadin.testbench.elements.ButtonElement;
+import com.vaadin.testbench.elements.LabelElement;
+import com.vaadin.tests.tb3.SingleBrowserTest;
+
+public class PushToggleComponentVisibilityTest extends SingleBrowserTest {
+
+    private static final String HIDE = "hide";
+
+    @Test
+    public void ensureComponentVisible() {
+        openTestURL();
+
+        $(ButtonElement.class).id(HIDE).click();
+        Assert.assertEquals("Please wait",
+                $(LabelElement.class).first().getText());
+
+        waitForElementPresent(By.id(HIDE));
+        $(ButtonElement.class).id(HIDE).click();
+        Assert.assertEquals("Please wait",
+                $(LabelElement.class).first().getText());
+    }
+}