refactor: remove the markingMode "full" machinery

Only markingMode "none" is supported. "full" was already non-functional:
its weak callback queued wrappers for processing that no longer existed, so
they were revived forever.

- ObjectManager always arms the finalizer path; the full-mode weak callback,
  its GC bookkeeping, the batch DirectBuffer plumbing and the unused
  declarations behind it are gone, as are DirectBuffer itself and the Java
  makeInstanceWeak(ByteBuffer)/checkWeakObjectAreAlive/getMarkingModeOrdinal.
- AppConfig drops the key (native config indices shift accordingly) and logs
  a warning when an app still sets markingMode to anything but "none".
- The __markingMode global is gone; testGC.js no longer gates on it, so its
  specs now run (they pass under the finalizer path).

Author: edusperoni

test-app/app/src/main/assets/app/package.json

@@ -6,7 +6,6 @@
 		"gcThrottleTime": 500,
 		"memoryCheckInterval": 10,
 		"freeMemoryRatio": 0.50,
-		"markingMode": "none",
 		"maxLogcatObjectSize": 1024,
 		"forceLog": false,
 		"suppressCallJSMethodExceptions": false,

test-app/app/src/main/assets/app/tests/testGC.js

@@ -1,7 +1,4 @@
-// Run GC tests only in Full marking mode
-let describeFunc = __markingMode == 0 ? describe : xdescribe;
-
-describeFunc("Tests garbage collection", function () {
+describe("Tests garbage collection", function () {
 	var myCustomEquality = function(first, second) {
 		return first == second;
 	};

test-app/runtime/CMakeLists.txt

@@ -182,7 +182,6 @@ add_library(
         src/main/cpp/ConcurrentQueue.cpp
         src/main/cpp/Constants.cpp
         src/main/cpp/CrashBreadcrumbs.cpp
-        src/main/cpp/DirectBuffer.cpp
         src/main/cpp/ErrorEvents.cpp
         src/main/cpp/EventLoop.cpp
         src/main/cpp/Events.cpp

test-app/runtime/src/main/cpp/DirectBuffer.cpp

@@ -20,7 +20,6 @@ using namespace tns;
 
 ObjectManager::ObjectManager(jobject javaRuntimeObject)
     : m_javaRuntimeObject(javaRuntimeObject),
-      m_numberOfGC(0),
       m_currentObjectId(0),
       m_cache(NewWeakGlobalRefCallback, DeleteWeakGlobalRefCallback,
               ValidateWeakGlobalRefCallback, 1000, this) {
@@ -37,12 +36,6 @@ ObjectManager::ObjectManager(jobject javaRuntimeObject)
   auto useGlobalRefs =
       env.CallStaticBooleanMethod(runtimeClass, useGlobalRefsMethodID);
   m_useGlobalRefs = useGlobalRefs == JNI_TRUE;
-
-  auto getMarkingModeOrdinalMethodID =
-      env.GetMethodID(runtimeClass, "getMarkingModeOrdinal", "()I");
-  jint markingMode =
-      env.CallIntMethod(m_javaRuntimeObject, getMarkingModeOrdinalMethodID);
-  m_markingMode = static_cast<JavaScriptMarkingMode>(markingMode);
 }
 
 void ObjectManager::InitializeJNI() {
@@ -60,10 +53,6 @@ void ObjectManager::InitializeJNI() {
       runtimeClass, "getOrCreateJavaObjectID", "(Ljava/lang/Object;)I");
   NS_CHECK(GET_OR_CREATE_JAVA_OBJECT_ID_METHOD_ID != nullptr);
 
-  MAKE_INSTANCE_WEAK_BATCH_METHOD_ID = env.GetMethodID(
-      runtimeClass, "makeInstanceWeak", "(Ljava/nio/ByteBuffer;IZ)V");
-  NS_CHECK(MAKE_INSTANCE_WEAK_BATCH_METHOD_ID != nullptr);
-
   MAKE_INSTANCE_WEAK_AND_CHECK_IF_ALIVE_METHOD_ID =
       env.GetMethodID(runtimeClass, "makeInstanceWeakAndCheckIfAlive", "(I)Z");
   NS_CHECK(MAKE_INSTANCE_WEAK_AND_CHECK_IF_ALIVE_METHOD_ID != nullptr);
@@ -72,11 +61,6 @@ void ObjectManager::InitializeJNI() {
       env.GetMethodID(runtimeClass, "releaseNativeCounterpart", "(I)V");
   NS_CHECK(RELEASE_NATIVE_INSTANCE_METHOD_ID != nullptr);
 
-  CHECK_WEAK_OBJECTS_ARE_ALIVE_METHOD_ID =
-      env.GetMethodID(runtimeClass, "checkWeakObjectAreAlive",
-                      "(Ljava/nio/ByteBuffer;Ljava/nio/ByteBuffer;I)V");
-  NS_CHECK(CHECK_WEAK_OBJECTS_ARE_ALIVE_METHOD_ID != nullptr);
-
   JAVA_LANG_CLASS = env.FindClass("java/lang/Class");
   NS_CHECK(JAVA_LANG_CLASS != nullptr);
 
@@ -328,19 +312,14 @@ void ObjectManager::Link(const Local<Object>& object, uint32_t javaObjectID,
               object->GetIdentityHash(), javaObjectID);
 
   auto jsInstanceInfo =
-      new JSInstanceInfo(false /*isJavaObjWeak*/, javaObjectID, clazz);
+      new JSInstanceInfo(javaObjectID, clazz);
 
   auto objectHandle = new Persistent<Object>(isolate, object);
   auto state = new ObjectWeakCallbackState(this, jsInstanceInfo, objectHandle);
 
   // subscribe for JS GC event
-  if (m_markingMode == JavaScriptMarkingMode::None) {
-    objectHandle->SetWeak(state, JSObjectFinalizerStatic,
-                          WeakCallbackType::kFinalizer);
-  } else {
-    objectHandle->SetWeak(state, JSObjectWeakCallbackStatic,
-                          WeakCallbackType::kFinalizer);
-  }
+  objectHandle->SetWeak(state, JSObjectFinalizerStatic,
+                        WeakCallbackType::kFinalizer);
 
   auto jsInfoIdx = static_cast<int>(MetadataNodeKeys::JsInfo);
 
@@ -390,17 +369,6 @@ string ObjectManager::GetClassName(jclass clazz) {
   return className;
 }
 
-void ObjectManager::JSObjectWeakCallbackStatic(
-    const WeakCallbackInfo<ObjectWeakCallbackState>& data) {
-  ObjectWeakCallbackState* callbackState = data.GetParameter();
-
-  ObjectManager* thisPtr = callbackState->thisPtr;
-
-  auto isolate = data.GetIsolate();
-
-  thisPtr->JSObjectWeakCallback(isolate, callbackState);
-}
-
 void ObjectManager::JSObjectFinalizerStatic(
     const WeakCallbackInfo<ObjectWeakCallbackState>& data) {
   ObjectWeakCallbackState* callbackState = data.GetParameter();
@@ -449,68 +417,6 @@ void ObjectManager::JSObjectFinalizer(Isolate* isolate,
   }
 }
 
-/*
- * When JS GC happens change state of the java counterpart to mirror state of JS
- * object and REVIVE the JS object unconditionally "Regular" js objects are
- * pushed into the "regular objects" array "Callback" js objects (ones that have
- * implementation object) are pushed into two "special objects" array: -ones
- * called for the first time which are originally strong in java -ones called
- * for the second or next time which are already weak in java too These objects
- * are categorized by "regular" and "callback" and saved in different arrays for
- * performance optimizations during GC
- * */
-void ObjectManager::JSObjectWeakCallback(
-    Isolate* isolate, ObjectWeakCallbackState* callbackState) {
-  HandleScope handleScope(isolate);
-
-  Persistent<Object>* po = callbackState->target;
-
-  auto itFound = m_visitedPOs.find(po);
-
-  if (itFound == m_visitedPOs.end()) {
-    m_visitedPOs.insert(po);
-
-    auto obj = Local<Object>::New(isolate, *po);
-    JSInstanceInfo* jsInstanceInfo = GetJSInstanceInfo(obj);
-
-    if (jsInstanceInfo != nullptr) {
-      int javaObjectID = jsInstanceInfo->JavaObjectID;
-
-      bool hasImplObj = HasImplObject(isolate, obj);
-
-      DEBUG_WRITE("JSObjectWeakCallback objectId: %d, hasImplObj=%d",
-                  javaObjectID, hasImplObj);
-
-      if (hasImplObj) {
-        if (jsInstanceInfo->IsJavaObjectWeak) {
-          m_implObjWeak.emplace_back(po, javaObjectID);
-        } else {
-          m_implObjStrong.emplace(javaObjectID, po);
-          jsInstanceInfo->IsJavaObjectWeak = true;
-        }
-      } else {
-        if (m_markedForGC.empty()) {
-          // Emulates the behavior in the OnGcStarted callback. Тhis is
-          // necessary as the hooking to the V8 GC is done only on the
-          // markSweepCompact phase. The JSObjectWeakCallback however is still
-          // triggered in other V8 GC phases (scavenger for example). This
-          // creates a problem that there is no 'top' on the m_markedForGC
-          // stack.
-          GarbageCollectionInfo gcInfo(++m_numberOfGC);
-          gcInfo.markedForGC.push_back(po);
-          m_markedForGC.push(gcInfo);
-        } else {
-          auto& topGCInfo = m_markedForGC.top();
-          topGCInfo.markedForGC.push_back(po);
-        }
-      }
-    }
-  }
-
-  po->SetWeak(callbackState, JSObjectWeakCallbackStatic,
-              WeakCallbackType::kFinalizer);
-}
-
 int ObjectManager::GenerateNewObjectID() {
   const int one = 1;
   int oldValue = __sync_fetch_and_add(&m_currentObjectId, one);
@@ -562,94 +468,6 @@ ObjectManager::~ObjectManager() {
   m_cache.clear();
 }
 
-void ObjectManager::ReleaseJSInstance(Persistent<Object>* po,
-                                      JSInstanceInfo* jsInstanceInfo) {
-  int javaObjectID = jsInstanceInfo->JavaObjectID;
-
-  auto it = m_idToObject.find(javaObjectID);
-
-  if (it == m_idToObject.end()) {
-    stringstream ss;
-    ss << "(InternalError): Js object with id: " << javaObjectID
-       << " not found";
-    throw NativeScriptException(ss.str());
-  }
-
-  NS_DCHECK(po == it->second->target);
-
-  ObjectWeakCallbackState* callbackState = it->second;
-  m_idToObject.erase(it);
-  delete callbackState;
-  m_released.insert(po, javaObjectID);
-  po->Reset();
-
-  delete po;
-  delete jsInstanceInfo;
-
-  DEBUG_WRITE("ReleaseJSObject instance disposed. id:%d", javaObjectID);
-}
-
-/*
- * The "regular" JS objects added on ObjectManager::JSObjectWeakCallback are
- * dealt with(released) here.
- * */
-void ObjectManager::ReleaseRegularObjects() {
-  TNSPERF();
-
-  HandleScope handleScope(m_isolate);
-
-  auto propName =
-      String::NewFromUtf8(m_isolate, "t::gcNum", NewStringType::kNormal)
-          .ToLocalChecked();
-
-  auto& topGCInfo = m_markedForGC.top();
-  auto& marked = topGCInfo.markedForGC;
-  int numberOfGC = topGCInfo.numberOfGC;
-
-  for (auto po : marked) {
-    if (m_released.contains(po)) {
-      continue;
-    }
-
-    auto obj = Local<Object>::New(m_isolate, *po);
-
-    NS_DCHECK(!obj.IsEmpty());
-
-    Local<Value> gcNum;
-    V8GetPrivateValue(m_isolate, obj, propName, gcNum);
-
-    bool isReachableFromImplementationObject = false;
-
-    if (!gcNum.IsEmpty() && gcNum->IsNumber()) {
-      double objGcNum = gcNum.As<Number>()->Value();
-
-      // done so we can release only java objects from this GC stack and pass
-      // all objects that will be released in parent GC stacks
-      isReachableFromImplementationObject = objGcNum >= numberOfGC;
-    }
-
-    JSInstanceInfo* jsInstanceInfo = GetJSInstanceInfo(obj);
-
-    if (!isReachableFromImplementationObject) {
-      if (!jsInstanceInfo->IsJavaObjectWeak) {
-        jsInstanceInfo->IsJavaObjectWeak = true;
-
-        ReleaseJSInstance(po, jsInstanceInfo);
-      }
-    }
-  }
-
-  marked.clear();
-}
-
-bool ObjectManager::HasImplObject(Isolate* isolate, const Local<Object>& obj) {
-  auto implObject = MetadataNode::GetImplementationObject(isolate, obj);
-
-  bool hasImplObj = !implObject.IsEmpty();
-
-  return hasImplObj;
-}
-
 jweak ObjectManager::NewWeakGlobalRefCallback(const int& javaObjectID,
                                               void* state) {
   auto objManager = reinterpret_cast<ObjectManager*>(state);
@@ -755,16 +573,10 @@ void ObjectManager::ReleaseNativeCounterpart(v8::Local<v8::Object>& object) {
   }
 }
 
-ObjectManager::JavaScriptMarkingMode ObjectManager::GetMarkingMode() {
-  return this->m_markingMode;
-}
-
 jclass ObjectManager::JAVA_LANG_CLASS = nullptr;
 jmethodID ObjectManager::GET_NAME_METHOD_ID = nullptr;
 jmethodID ObjectManager::GET_JAVAOBJECT_BY_ID_METHOD_ID = nullptr;
 jmethodID ObjectManager::GET_OR_CREATE_JAVA_OBJECT_ID_METHOD_ID = nullptr;
-jmethodID ObjectManager::MAKE_INSTANCE_WEAK_BATCH_METHOD_ID = nullptr;
 jmethodID ObjectManager::MAKE_INSTANCE_WEAK_AND_CHECK_IF_ALIVE_METHOD_ID =
     nullptr;
 jmethodID ObjectManager::RELEASE_NATIVE_INSTANCE_METHOD_ID = nullptr;
-jmethodID ObjectManager::CHECK_WEAK_OBJECTS_ARE_ALIVE_METHOD_ID = nullptr;