From 124f874b4aaa0fdb7d6eeda52847bf30e9169e93 Mon Sep 17 00:00:00 2001
From: Konstantin Shcheglov <scheglov@google.com>
Date: Mon, 17 Apr 2017 09:41:49 -0700
Subject: [PATCH] Make copy of the drivers list in SearchEngineImpl2 to avoid
 ConcurrentModificationError.

I think this happens when a driver is disposed why search is in
progress. So, we need to make defensive copies.

This also makes me realize that we don't handle situations when
a driver instance is disposed, but it has pending requests, such as
getResult(), getIndex(), etc - actually any getXXX(), and search. As
it is now, I think we just leave these Future(s) and they never
complete.

R=brianwilkerson@google.com
BUG=

Review-Url: https://codereview.chromium.org/2818163003 .
---
 .../services/search/search_engine_internal2.dart  | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/pkg/analysis_server/lib/src/services/search/search_engine_internal2.dart b/pkg/analysis_server/lib/src/services/search/search_engine_internal2.dart
index d9088a9d9d3..6f1336fd2b5 100644
--- a/pkg/analysis_server/lib/src/services/search/search_engine_internal2.dart
+++ b/pkg/analysis_server/lib/src/services/search/search_engine_internal2.dart
@@ -39,7 +39,8 @@ class SearchEngineImpl2 implements SearchEngine {
   @override
   Future<List<SearchMatch>> searchMemberDeclarations(String name) async {
     List<SearchMatch> allDeclarations = [];
-    for (AnalysisDriver driver in _drivers) {
+    List<AnalysisDriver> drivers = _drivers.toList();
+    for (AnalysisDriver driver in drivers) {
       List<Element> elements = await driver.search.classMembers(name);
       allDeclarations.addAll(elements.map(_SearchMatch.forElement));
     }
@@ -49,7 +50,8 @@ class SearchEngineImpl2 implements SearchEngine {
   @override
   Future<List<SearchMatch>> searchMemberReferences(String name) async {
     List<SearchResult> allResults = [];
-    for (AnalysisDriver driver in _drivers) {
+    List<AnalysisDriver> drivers = _drivers.toList();
+    for (AnalysisDriver driver in drivers) {
       List<SearchResult> results =
           await driver.search.unresolvedMemberReferences(name);
       allResults.addAll(results);
@@ -60,7 +62,8 @@ class SearchEngineImpl2 implements SearchEngine {
   @override
   Future<List<SearchMatch>> searchReferences(Element element) async {
     List<SearchResult> allResults = [];
-    for (AnalysisDriver driver in _drivers) {
+    List<AnalysisDriver> drivers = _drivers.toList();
+    for (AnalysisDriver driver in drivers) {
       List<SearchResult> results = await driver.search.references(element);
       allResults.addAll(results);
     }
@@ -77,7 +80,8 @@ class SearchEngineImpl2 implements SearchEngine {
   Future<List<SearchMatch>> searchTopLevelDeclarations(String pattern) async {
     List<SearchMatch> allDeclarations = [];
     RegExp regExp = new RegExp(pattern);
-    for (AnalysisDriver driver in _drivers) {
+    List<AnalysisDriver> drivers = _drivers.toList();
+    for (AnalysisDriver driver in drivers) {
       List<Element> elements = await driver.search.topLevelElements(regExp);
       allDeclarations.addAll(elements.map(_SearchMatch.forElement));
     }
@@ -86,7 +90,8 @@ class SearchEngineImpl2 implements SearchEngine {
 
   Future<List<SearchResult>> _searchDirectSubtypes(ClassElement type) async {
     List<SearchResult> allResults = [];
-    for (AnalysisDriver driver in _drivers) {
+    List<AnalysisDriver> drivers = _drivers.toList();
+    for (AnalysisDriver driver in drivers) {
       List<SearchResult> results = await driver.search.subTypes(type);
       allResults.addAll(results);
     }