Issue 3594 - remove circular references JsEngine-JsValue-JsEngine

test/FilterEngine.cpp

Index: test/FilterEngine.cpp
diff --git a/test/FilterEngine.cpp b/test/FilterEngine.cpp
index 177c0c7f2147850c3d846786858b9817c14155b3..c1c34f36231c207ea2d6ca09e3b4a24ab3a80ba9 100644
--- a/test/FilterEngine.cpp
+++ b/test/FilterEngine.cpp
@@ -16,6 +16,8 @@
  */
 
 #include "BaseJsTest.h"
+#include <thread>
+#include <chrono>
 
 namespace
 {
@@ -533,3 +535,27 @@ TEST_F(FilterEngineTest, ElemhideWhitelisting)
       "http://example.co.uk",
       documentUrls1));
 }
+
+TEST(NewFilterEngineTest, MemoryLeak_NoCircularReferences)
+{
+  std::weak_ptr<AdblockPlus::JsEngine> weakJsEngine;
+  {
+    auto jsEngine = AdblockPlus::JsEngine::New();
+    weakJsEngine = jsEngine;
+    jsEngine->SetFileSystem(AdblockPlus::FileSystemPtr(new LazyFileSystem()));
+    jsEngine->SetWebRequest(AdblockPlus::WebRequestPtr(new LazyWebRequest()));
+    jsEngine->SetLogSystem(AdblockPlus::LogSystemPtr(new LazyLogSystem()));
+    auto filterEngine = FilterEnginePtr(new AdblockPlus::FilterEngine(jsEngine));
+  }
+  {
+    // It's a hack to figure current race condition out (better than nothing):
+    // IO or timer thread still can aquire a strong reference to JsEngine right
+    // before destroying filterEngine holding JsEngine and keep it for some
+    // time, so here we need to give it a reasonable amount of time to finish
+    // the current operation.
+    uint16_t attempts = 10;
+    while (attempts-- > 0 && weakJsEngine.lock())
+      std::this_thread::sleep_for(std::chrono::milliseconds(500));
+  }
+  EXPECT_FALSE(weakJsEngine.lock());
+}