From 6e71e9ddbda65bb681b18cdcbd5603a914e32eab Mon Sep 17 00:00:00 2001
From: Dmitry Batrak <Dmitry.Batrak@jetbrains.com>
Date: Thu, 11 Jan 2018 18:03:12 +0300
Subject: [PATCH] CPP-10107 Freezes while looking up Doxygen comments

avoid multiple requests running simultaneously on different threads
---
 .../navigation/CtrlMouseHandler.java          | 25 +++++++------------
 1 file changed, 9 insertions(+), 16 deletions(-)

diff --git a/platform/lang-impl/src/com/intellij/codeInsight/navigation/CtrlMouseHandler.java b/platform/lang-impl/src/com/intellij/codeInsight/navigation/CtrlMouseHandler.java
index 058568f7fc46..2a8fcbfcf9ff 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/navigation/CtrlMouseHandler.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/navigation/CtrlMouseHandler.java
@@ -1,17 +1,5 @@
 /*
- * Copyright 2000-2017 JetBrains s.r.o.
- *
- * 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.
+ * Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
  */
 
 package com.intellij.codeInsight.navigation;
@@ -34,7 +22,6 @@ import com.intellij.navigation.NavigationItem;
 import com.intellij.openapi.actionSystem.IdeActions;
 import com.intellij.openapi.actionSystem.impl.ActionButton;
 import com.intellij.openapi.actionSystem.impl.PresentationFactory;
-import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.components.AbstractProjectComponent;
 import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.editor.Document;
@@ -100,6 +87,7 @@ import java.util.ArrayList;
 import java.util.Collections;
 import java.util.EventObject;
 import java.util.List;
+import java.util.concurrent.atomic.AtomicReference;
 
 public class CtrlMouseHandler extends AbstractProjectComponent {
   private static final Logger LOG = Logger.getInstance("#com.intellij.codeInsight.navigation.CtrlMouseHandler");
@@ -115,6 +103,7 @@ public class CtrlMouseHandler extends AbstractProjectComponent {
   private final DocumentationManager myDocumentationManager;
   @Nullable private Point myPrevMouseLocation;
   private LightweightHint myHint;
+  private final AtomicReference<ProgressIndicator> myCurrentRequestProgress = new AtomicReference<>();
 
   public enum BrowseMode {None, Declaration, TypeDeclaration, Implementation}
 
@@ -652,7 +641,8 @@ public class CtrlMouseHandler extends AbstractProjectComponent {
                               @NotNull final Consumer<String> newTextConsumer,
                               @NotNull final LightweightHint hint)
   {
-    myDocAlarm.cancelAllRequests();
+    ProgressIndicatorBase progress = new ProgressIndicatorBase();
+    myCurrentRequestProgress.set(progress);
     myDocAlarm.addRequest(() -> {
       final Ref<String> fullTextRef = new Ref<>();
       final Ref<String> qualifiedNameRef = new Ref<>();
@@ -668,7 +658,8 @@ public class CtrlMouseHandler extends AbstractProjectComponent {
             qualifiedNameRef.set(((PsiQualifiedNamedElement)anchorElement).getQualifiedName());
           }
         }
-      }, DOC_GENERATION_TIMEOUT_MS, DOC_GENERATION_RETRY_DELAY_MS, null);
+      }, DOC_GENERATION_TIMEOUT_MS, DOC_GENERATION_RETRY_DELAY_MS, progress);
+      myCurrentRequestProgress.compareAndSet(progress, null);
       String fullText = fullTextRef.get();
       if (fullText == null) {
         return;
@@ -930,6 +921,8 @@ public class CtrlMouseHandler extends AbstractProjectComponent {
         }
       });
       myDocAlarm.cancelAllRequests();
+      ProgressIndicator currentIndicator = myCurrentRequestProgress.getAndSet(null);
+      if (currentIndicator != null) currentIndicator.cancel(); 
       if (newTextConsumer != null && docInfo.docProvider != null && docInfo.documentationAnchor != null) {
         fulfillDocInfo(docInfo.text, docInfo.docProvider, info.myElementAtPointer, docInfo.documentationAnchor, newTextConsumer, hint);
       }