[K/N] Make gc::SweepExtraObjects similar to gc::Sweep. ^KT-56233

kotlin-native/runtime/src/gc/cms/cpp/ConcurrentMarkAndSweep.cpp

@@ -180,8 +180,8 @@ bool gc::ConcurrentMarkAndSweep::PerformFullGC(int64_t epoch) noexcept {
     scheduler.gcData().UpdateAliveSetBytes(markStats.totalObjectsSize);
 
 #ifndef CUSTOM_ALLOCATOR
-    mm::ExtraObjectDataFactory& extraObjectDataFactory = mm::GlobalData::Instance().extraObjectDataFactory();
-    gc::SweepExtraObjects<SweepTraits>(gcHandle, extraObjectDataFactory);
+    auto extraObjectFactoryIterable = mm::GlobalData::Instance().extraObjectDataFactory().LockForIter();
+    gc::SweepExtraObjects<SweepTraits>(gcHandle, extraObjectFactoryIterable);
 
     auto objectFactoryIterable = objectFactory_.LockForIter();
     mm::ResumeThreads();

kotlin-native/runtime/src/gc/common/cpp/MarkAndSweepUtils.hpp

@@ -108,11 +108,10 @@ void Mark(GCHandle handle, typename Traits::MarkQueue& markQueue) noexcept {
 }
 
 template <typename Traits>
-void SweepExtraObjects(GCHandle handle, typename Traits::ExtraObjectsFactory& objectFactory) noexcept {
-    objectFactory.ProcessDeletions();
+void SweepExtraObjects(GCHandle handle, typename Traits::ExtraObjectsFactory::Iterable& factoryIter) noexcept {
     auto sweepHandle = handle.sweepExtraObjects();
-    auto iter = objectFactory.LockForIter();
-    for (auto it = iter.begin(); it != iter.end();) {
+    factoryIter.ApplyDeletions();
+    for (auto it = factoryIter.begin(); it != factoryIter.end();) {
         auto &extraObject = *it;
         if (!extraObject.getFlag(mm::ExtraObjectData::FLAGS_IN_FINALIZER_QUEUE) && !Traits::IsMarkedByExtraObject(extraObject)) {
             extraObject.ClearWeakReferenceCounter();
@@ -122,7 +121,7 @@ void SweepExtraObjects(GCHandle handle, typename Traits::ExtraObjectsFactory& ob
                 ++it;
             } else {
                 extraObject.Uninstall();
-                objectFactory.EraseAndAdvance(it);
+                it.EraseAndAdvance();
             }
         } else {
             ++it;
@@ -130,6 +129,12 @@ void SweepExtraObjects(GCHandle handle, typename Traits::ExtraObjectsFactory& ob
     }
 }
 
+template <typename Traits>
+void SweepExtraObjects(GCHandle handle, typename Traits::ExtraObjectsFactory& factory) noexcept {
+    auto iter = factory.LockForIter();
+    return SweepExtraObjects<Traits>(handle, iter);
+}
+
 template <typename Traits>
 typename Traits::ObjectFactory::FinalizerQueue Sweep(GCHandle handle, typename Traits::ObjectFactory::Iterable& objectFactoryIter) noexcept {
     typename Traits::ObjectFactory::FinalizerQueue finalizerQueue;

kotlin-native/runtime/src/main/cpp/MultiSourceQueue.hpp

@@ -38,6 +38,7 @@ public:
         explicit Node(Producer* owner, Args&& ...args) noexcept : value_(std::forward<Args>(args)...), owner_(owner) {}
 
         T& operator*() noexcept { return value_; }
+        T* operator->() noexcept { return &value_; }
 
         static Node& fromValue(T& t) noexcept {
             static_assert(std::is_base_of_v<Pinned, T>, "fromValue function only makes sense for non-movable object");
@@ -111,12 +112,15 @@ public:
     class Iterator {
     public:
         T& operator*() noexcept { return **position_; }
+        T* operator->() noexcept { return &*this; }
 
         Iterator& operator++() noexcept {
             ++position_;
             return *this;
         }
 
+        void EraseAndAdvance() noexcept { owner_->EraseAndAdvance(*this); }
+
         bool operator==(const Iterator& rhs) const noexcept { return position_ == rhs.position_; }
 
         bool operator!=(const Iterator& rhs) const noexcept { return position_ != rhs.position_; }
@@ -124,15 +128,18 @@ public:
     private:
         friend class MultiSourceQueue;
 
-        explicit Iterator(const typename List<Node>::iterator& position) noexcept : position_(position) {}
+        Iterator(MultiSourceQueue& owner, const typename List<Node>::iterator& position) noexcept : owner_(&owner), position_(position) {}
 
+        MultiSourceQueue* owner_;
         typename List<Node>::iterator position_;
     };
 
     class Iterable : MoveOnly {
     public:
-        Iterator begin() noexcept { return Iterator(owner_.queue_.begin()); }
-        Iterator end() noexcept { return Iterator(owner_.queue_.end()); }
+        Iterator begin() noexcept { return Iterator(owner_, owner_.queue_.begin()); }
+        Iterator end() noexcept { return Iterator(owner_, owner_.queue_.end()); }
+
+        void ApplyDeletions() noexcept { owner_.ApplyDeletionsUnsafe(); }
 
     private:
         friend class MultiSourceQueue;
@@ -152,6 +159,22 @@ public:
     // Lock `MultiSourceQueue` and apply deletions. Only deletes elements that were published.
     void ApplyDeletions() noexcept {
         std::lock_guard<Mutex> guard(mutex_);
+        ApplyDeletionsUnsafe();
+    }
+
+    // requires LockForIter
+    void EraseAndAdvance(Iterator& it) { it.position_ = queue_.erase(it.position_); }
+
+    void ClearForTests() noexcept {
+        queue_.clear();
+        deletionQueue_.clear();
+    }
+
+    size_t GetSizeUnsafe() noexcept { return queue_.size(); }
+
+private:
+    // Requires a lock to be taken externally.
+    void ApplyDeletionsUnsafe() noexcept {
         List<Node*> remainingDeletions(deletionQueue_.get_allocator());
 
         auto it = deletionQueue_.begin();
@@ -172,21 +195,6 @@ public:
         deletionQueue_ = std::move(remainingDeletions);
     }
 
-    // requires LockForIter
-    void EraseAndAdvance(Iterator &it) {
-        it.position_ = queue_.erase(it.position_);
-    }
-
-    void ClearForTests() noexcept {
-        queue_.clear();
-        deletionQueue_.clear();
-    }
-
-    size_t GetSizeUnsafe() noexcept {
-        return queue_.size();
-    }
-
-private:
     List<Node> queue_;
     List<Node*> deletionQueue_;
     Mutex mutex_;