Issue 5002 - Fix potential concurrency issues in WebRequest tests.

test/WebRequest.cpp

Index: test/WebRequest.cpp
===================================================================
--- a/test/WebRequest.cpp
+++ b/test/WebRequest.cpp
@@ -25,20 +25,25 @@
 
 namespace
 {
   class MockWebRequest : public AdblockPlus::WebRequest
   {
   public:
     AdblockPlus::ServerResponse GET(const std::string& url, const AdblockPlus::HeaderList& requestHeaders) const
     {
-      lastRequestHeaders.clear();
+      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.

       for (auto header : requestHeaders)
       {
-        lastRequestHeaders.insert(header.first);
+        r.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)));
       }
 
       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"));
@@ -46,17 +51,18 @@
       if (!requestHeaders.empty())
       {
         result.responseText += requestHeaders[0].first + "\n" + requestHeaders[0].second;
       }
       return result;
     }
 
     // mutable. Very Ugly. But we are testing and need to change this in GET which is const.
-    mutable std::set<std::string> lastRequestHeaders;
+    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.

   };
 
   template<class T>
   class WebRequestTest : public BaseJsTest
   {
   protected:
     void SetUp()
     {
@@ -65,26 +71,36 @@
       jsEngine->SetFileSystem(AdblockPlus::FileSystemPtr(new LazyFileSystem()));
     }
   };
 
   typedef WebRequestTest<MockWebRequest> MockWebRequestTest;
   typedef WebRequestTest<AdblockPlus::DefaultWebRequest> DefaultWebRequestTest;
   typedef WebRequestTest<MockWebRequest> XMLHttpRequestTest;
 
-  void ResetTestXHR(const AdblockPlus::JsEnginePtr& jsEngine)
+  // we return the url of the XHR.
+  std::string ResetTestXHR(const AdblockPlus::JsEnginePtr& jsEngine, const std::string& defaultUrl = "")
   {
-    jsEngine->Evaluate("\
+    std::string url = defaultUrl;
+    // make up a unique URL if we don't have one.
+    if (url == "")
+    {
+      url = "https://tests.adblockplus.org/easylist.txt-";
+      url += std::to_string(std::chrono::system_clock::to_time_t(std::chrono::system_clock::now()));
+    }
+
+    jsEngine->Evaluate(std::string("\
       var result;\
       var request = new XMLHttpRequest();\
-      request.open('GET', 'https://easylist-downloads.adblockplus.org/easylist.txt');\
+      request.open('GET', '") + url + "'); \
       request.overrideMimeType('text/plain');\
       request.addEventListener('load', function() {result = request.responseText;}, false);\
       request.addEventListener('error', function() {result = 'error';}, false);\
     ");
+    return url;
   }
 
   void WaitForVariable(const std::string& variable, const AdblockPlus::JsEnginePtr& jsEngine)
   {
     do
     {
       AdblockPlus::Sleep(60);
     } while (jsEngine->Evaluate(variable)->IsUndefined());
@@ -130,17 +146,17 @@
 #endif
   ASSERT_TRUE(jsEngine->Evaluate("foo.responseHeaders['location']")->IsUndefined());
 }
 
 TEST_F(DefaultWebRequestTest, XMLHttpRequest)
 {
   auto filterEngine = AdblockPlus::FilterEngine::Create(jsEngine);
 
-  ResetTestXHR(jsEngine);
+  ResetTestXHR(jsEngine, "https://easylist-downloads.adblockplus.org/easylist.txt");
   jsEngine->Evaluate("\
     request.setRequestHeader('X', 'Y');\
     request.setRequestHeader('X2', 'Y2');\
     request.send(null);");
   WaitForVariable("result", jsEngine);
   ASSERT_EQ(AdblockPlus::WebRequest::NS_OK, jsEngine->Evaluate("request.channel.status")->AsInt());
   ASSERT_EQ(200, jsEngine->Evaluate("request.status")->AsInt());
   ASSERT_EQ("[Adblock Plus ", jsEngine->Evaluate("result.substr(0, 14)")->AsString());
@@ -223,72 +239,108 @@
   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();
-  ResetTestXHR(jsEngine);
+  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);
-  EXPECT_TRUE(webRequest->lastRequestHeaders.cend() ==
-              webRequest->lastRequestHeaders.find("Accept-Encoding"));
+  {
+    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;
+    EXPECT_TRUE(headers.cend() == headers.find("Accept-Encoding"));
+    webRequest->lastRequestHeaders.erase(iter);
+  }
 
   // test 'DNT' is rejected
   catchLogSystem->clear();
-  ResetTestXHR(jsEngine);
+  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);
-  EXPECT_TRUE(webRequest->lastRequestHeaders.cend() ==
-              webRequest->lastRequestHeaders.find("DNT"));
+  {
+    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;
+    EXPECT_TRUE(headers.cend() == headers.find("DNT"));
+    webRequest->lastRequestHeaders.erase(iter);
+  }
 
   // test random 'X' header is accepted
   catchLogSystem->clear();
-  ResetTestXHR(jsEngine);
+  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);
-  EXPECT_FALSE(webRequest->lastRequestHeaders.cend() ==
-               webRequest->lastRequestHeaders.find("X"));
+  {
+    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;
+    EXPECT_FALSE(headers.cend() == headers.find("X"));
+    webRequest->lastRequestHeaders.erase(iter);
+  }
 
   // test /^Proxy-/ is rejected.
   catchLogSystem->clear();
-  ResetTestXHR(jsEngine);
+  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);
-  EXPECT_TRUE(webRequest->lastRequestHeaders.cend() ==
-              webRequest->lastRequestHeaders.find("Proxy-foo"));
+  {
+    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;
+    EXPECT_TRUE(headers.cend() == headers.find("Proxy-foo"));
+    webRequest->lastRequestHeaders.erase(iter);
+  }
 
   // test /^Sec-/ is rejected.
   catchLogSystem->clear();
-  ResetTestXHR(jsEngine);
+  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);
-  EXPECT_TRUE(webRequest->lastRequestHeaders.cend() ==
-              webRequest->lastRequestHeaders.find("Sec-foo"));
+  {
+    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;
+    EXPECT_TRUE(headers.cend() == headers.find("Sec-foo"));
+    webRequest->lastRequestHeaders.erase(iter);
+  }
 
   // test 'Security' is accepted.
   catchLogSystem->clear();
-  ResetTestXHR(jsEngine);
+  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);
-  EXPECT_FALSE(webRequest->lastRequestHeaders.cend() ==
-               webRequest->lastRequestHeaders.find("Security"));
+  {
+    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;
+    EXPECT_FALSE(headers.cend() == headers.find("Security"));
+    webRequest->lastRequestHeaders.erase(iter);
+  }
 }