Issue 5002 - Fix potential concurrency issues in WebRequest tests.

test/WebRequest.cpp

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2017 eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 12 matching lines @@
 
 using namespace AdblockPlus;
 
 namespace
 {
   class MockWebRequest : public AdblockPlus::WebRequest
   {
   public:
     AdblockPlus::ServerResponse GET(const std::string& url, const AdblockPlus::HeaderList& requestHeaders) const
     {
-      std::set<std::string> r;

[sergei, 2017/04/19 10:38:31]

what about renaming here?

r -> headerNames

[hub, 2017/04/19 13:12:04]

Done.

+      std::set<std::string> headerNames;
       for (auto header : requestHeaders)
       {
-        r.insert(header.first);
+        headerNames.insert(header.first);
       }
       {
-        std::lock_guard<std::mutex> lock(lastRequestHeadersMutex);
-        // XXX we currently ignore the result. We should check it actually gets inserted.

[sergei, 2017/04/19 10:38:31]

It would be better to remove XXX.

[hub, 2017/04/19 13:12:04]

Acknowledged.

-        lastRequestHeaders.insert(std::make_pair(url, std::move(r)));
+        std::lock_guard<std::mutex> lock(requestHeaderNamesMutex);
+        // we currently ignore the result. We should check it actually gets inserted.
+        requestHeaderNames.insert(std::make_pair(url, std::move(headerNames)));
       }
 
       AdblockPlus::Sleep(50);
 
       AdblockPlus::ServerResponse result;
       result.status = NS_OK;
       result.responseStatus = 123;
       result.responseHeaders.push_back(std::pair<std::string, std::string>("Foo", "Bar"));
       result.responseText = url + "\n";
       if (!requestHeaders.empty())
       {
         result.responseText += requestHeaders[0].first + "\n" + requestHeaders[0].second;
       }
       return result;
     }
 
+    // Testing method
+    // Get the headers for the request. Return a pair of a bool (found
+    // or not) and the actual header names
+    std::pair<bool, std::set<std::string>> headersForRequest(const std::string& url)
+    {
+      std::lock_guard<std::mutex> lock(requestHeaderNamesMutex);
+      auto iter = requestHeaderNames.find(url);
+      if (iter != requestHeaderNames.end())
+      {
+        auto result = std::make_pair(true, iter->second);
+        requestHeaderNames.erase(iter);
+        return result;
+      }
+      return std::make_pair(false, std::set<std::string>());
+    }
+
     // mutable. Very Ugly. But we are testing and need to change this in GET which is const.
-    mutable std::mutex lastRequestHeadersMutex;
-    mutable std::map<std::string, std::set<std::string>> lastRequestHeaders;

[sergei, 2017/04/19 10:38:31]

because now it's not only for last requests

lastRequestHeaders -> requestsHeaderNames

and also for mutex.

[hub, 2017/04/19 13:12:04]

Done.

+    mutable std::mutex requestHeaderNamesMutex;
+    mutable std::map<std::string, std::set<std::string>> requestHeaderNames;
   };
 
   template<class T>
   class WebRequestTest : public BaseJsTest
   {
   protected:
     void SetUp()
     {
       BaseJsTest::SetUp();
-      jsEngine->SetWebRequest(AdblockPlus::WebRequestPtr(new T()));
+      webRequest = std::make_shared<T>();
+      jsEngine->SetWebRequest(webRequest);
       jsEngine->SetFileSystem(AdblockPlus::FileSystemPtr(new LazyFileSystem()));
     }
+
+    std::shared_ptr<T> webRequest;
   };
 
   typedef WebRequestTest<MockWebRequest> MockWebRequestTest;
   typedef WebRequestTest<AdblockPlus::DefaultWebRequest> DefaultWebRequestTest;
   typedef WebRequestTest<MockWebRequest> XMLHttpRequestTest;
 
   // we return the url of the XHR.
   std::string ResetTestXHR(const AdblockPlus::JsEnginePtr& jsEngine, const std::string& defaultUrl = "")
   {
     std::string url = defaultUrl;
@@ skipping 141 matching lines @@
 
   typedef std::shared_ptr<CatchLogSystem> CatchLogSystemPtr;
 }
 
 TEST_F(XMLHttpRequestTest, RequestHeaderValidation)
 {
   auto catchLogSystem = CatchLogSystemPtr(new CatchLogSystem());
   jsEngine->SetLogSystem(catchLogSystem);
 
   auto filterEngine = AdblockPlus::FilterEngine::Create(jsEngine);
-  auto webRequest =
-    std::static_pointer_cast<MockWebRequest>(jsEngine->GetWebRequest());
-
-  ASSERT_TRUE(webRequest);
 
   const std::string msg = "Attempt to set a forbidden header was denied: ";
 
   // The test will check that console.warn has been called when the
   // header is rejected. While this is an implementation detail, we
   // have no other way to check this
 
   // test 'Accept-Encoding' is rejected
   catchLogSystem->clear();
   std::string url = ResetTestXHR(jsEngine);
   jsEngine->Evaluate("\
     request.setRequestHeader('Accept-Encoding', 'gzip');\nrequest.send();");
   EXPECT_EQ(AdblockPlus::LogSystem::LOG_LEVEL_WARN, catchLogSystem->lastLogLevel);
   EXPECT_EQ(msg + "Accept-Encoding", catchLogSystem->lastMessage);
   WaitForVariable("result", jsEngine);
   {
-    std::lock_guard<std::mutex> lock(webRequest->lastRequestHeadersMutex);

[sergei, 2017/04/19 10:38:31]

any work with the mutex of webRequest should be moved into a method of
webRequest. For instance to a method returning a set of header names and
atomically removing it from the map. I would recommend to have a smart pointer
to MockWebRequest as a member of the fixture class.

[hub, 2017/04/19 13:12:04]

Done.

-    const auto& iter = webRequest->lastRequestHeaders.find(url);
-    EXPECT_TRUE(iter != webRequest->lastRequestHeaders.end());
-    const auto& headers = iter->second;
+    auto headersRequest = webRequest->headersForRequest(url);
+    EXPECT_TRUE(headersRequest.first);
+    const auto& headers = headersRequest.second;
     EXPECT_TRUE(headers.cend() == headers.find("Accept-Encoding"));
-    webRequest->lastRequestHeaders.erase(iter);
   }
 
   // test 'DNT' is rejected
   catchLogSystem->clear();
   url = ResetTestXHR(jsEngine);
   jsEngine->Evaluate("\
     request.setRequestHeader('DNT', '1');\nrequest.send();");
   EXPECT_EQ(AdblockPlus::LogSystem::LOG_LEVEL_WARN, catchLogSystem->lastLogLevel);
   EXPECT_EQ(msg + "DNT", catchLogSystem->lastMessage);
   WaitForVariable("result", jsEngine);
   {
-    std::lock_guard<std::mutex> lock(webRequest->lastRequestHeadersMutex);
-    const auto& iter = webRequest->lastRequestHeaders.find(url);
-    EXPECT_TRUE(iter != webRequest->lastRequestHeaders.end());
-    const auto& headers = iter->second;
+    auto headersRequest = webRequest->headersForRequest(url);
+    EXPECT_TRUE(headersRequest.first);
+    const auto& headers = headersRequest.second;
     EXPECT_TRUE(headers.cend() == headers.find("DNT"));
-    webRequest->lastRequestHeaders.erase(iter);
   }
 
   // test random 'X' header is accepted
   catchLogSystem->clear();
   url = ResetTestXHR(jsEngine);
   jsEngine->Evaluate("\
     request.setRequestHeader('X', 'y');\nrequest.send();");
   EXPECT_EQ(AdblockPlus::LogSystem::LOG_LEVEL_TRACE, catchLogSystem->lastLogLevel);
   EXPECT_EQ("", catchLogSystem->lastMessage);
   WaitForVariable("result", jsEngine);
   {
-    std::lock_guard<std::mutex> lock(webRequest->lastRequestHeadersMutex);
-    const auto& iter = webRequest->lastRequestHeaders.find(url);
-    EXPECT_TRUE(iter != webRequest->lastRequestHeaders.end());
-    const auto& headers = iter->second;
+    auto headersRequest = webRequest->headersForRequest(url);
+    EXPECT_TRUE(headersRequest.first);
+    const auto& headers = headersRequest.second;
     EXPECT_FALSE(headers.cend() == headers.find("X"));
-    webRequest->lastRequestHeaders.erase(iter);
   }
 
   // test /^Proxy-/ is rejected.
   catchLogSystem->clear();
   url = ResetTestXHR(jsEngine);
   jsEngine->Evaluate("\
     request.setRequestHeader('Proxy-foo', 'bar');\nrequest.send();");
   EXPECT_EQ(AdblockPlus::LogSystem::LOG_LEVEL_WARN, catchLogSystem->lastLogLevel);
   EXPECT_EQ(msg + "Proxy-foo", catchLogSystem->lastMessage);
   WaitForVariable("result", jsEngine);
   {
-    std::lock_guard<std::mutex> lock(webRequest->lastRequestHeadersMutex);
-    const auto& iter = webRequest->lastRequestHeaders.find(url);
-    EXPECT_TRUE(iter != webRequest->lastRequestHeaders.end());
-    const auto& headers = iter->second;
+    auto headersRequest = webRequest->headersForRequest(url);
+    EXPECT_TRUE(headersRequest.first);
+    const auto& headers = headersRequest.second;
     EXPECT_TRUE(headers.cend() == headers.find("Proxy-foo"));
-    webRequest->lastRequestHeaders.erase(iter);
   }
 
   // test /^Sec-/ is rejected.
   catchLogSystem->clear();
   url = ResetTestXHR(jsEngine);
   jsEngine->Evaluate("\
     request.setRequestHeader('Sec-foo', 'bar');\nrequest.send();");
   EXPECT_EQ(AdblockPlus::LogSystem::LOG_LEVEL_WARN, catchLogSystem->lastLogLevel);
   EXPECT_EQ(msg + "Sec-foo", catchLogSystem->lastMessage);
   WaitForVariable("result", jsEngine);
   {
-    std::lock_guard<std::mutex> lock(webRequest->lastRequestHeadersMutex);
-    const auto& iter = webRequest->lastRequestHeaders.find(url);
-    EXPECT_TRUE(iter != webRequest->lastRequestHeaders.end());
-    const auto& headers = iter->second;
+    auto headersRequest = webRequest->headersForRequest(url);
+    EXPECT_TRUE(headersRequest.first);
+    const auto& headers = headersRequest.second;
     EXPECT_TRUE(headers.cend() == headers.find("Sec-foo"));
-    webRequest->lastRequestHeaders.erase(iter);
   }
 
   // test 'Security' is accepted.
   catchLogSystem->clear();
   url = ResetTestXHR(jsEngine);
   jsEngine->Evaluate("\
     request.setRequestHeader('Security', 'theater');\nrequest.send();");
   EXPECT_EQ(AdblockPlus::LogSystem::LOG_LEVEL_TRACE, catchLogSystem->lastLogLevel);
   EXPECT_EQ("", catchLogSystem->lastMessage);
   WaitForVariable("result", jsEngine);
   {
-    std::lock_guard<std::mutex> lock(webRequest->lastRequestHeadersMutex);
-    const auto& iter = webRequest->lastRequestHeaders.find(url);
-    EXPECT_TRUE(iter != webRequest->lastRequestHeaders.end());
-    const auto& headers = iter->second;
+    auto headersRequest = webRequest->headersForRequest(url);
+    EXPECT_TRUE(headersRequest.first);
+    const auto& headers = headersRequest.second;
     EXPECT_FALSE(headers.cend() == headers.find("Security"));
-    webRequest->lastRequestHeaders.erase(iter);
-  }
-}
+  }
+}