[K/N] Reuse mark queue ^KT-51436

Merge-request: KT-MR-5819
Merged-by: Alexander Shabalin <Alexander.Shabalin@jetbrains.com>

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

@@ -85,6 +85,7 @@ gc::ConcurrentMarkAndSweep::ConcurrentMarkAndSweep(
     objectFactory_(objectFactory),
     gcScheduler_(gcScheduler),
     finalizerProcessor_(make_unique<FinalizerProcessor>([this](int64_t epoch) { state_.finalized(epoch); })) {
+    graySet_.reserve(1000);
     gcScheduler_.SetScheduleGC([this]() NO_INLINE {
         RuntimeLogDebug({kTagGC}, "Scheduling GC by thread %d", konan::currentThreadId());
         // This call acquires a lock, so we need to ensure that we're in the safe state.
@@ -142,15 +143,15 @@ bool gc::ConcurrentMarkAndSweep::PerformFullGC(int64_t epoch) noexcept {
     state_.start(epoch);
     RuntimeLogInfo(
             {kTagGC}, "Started GC epoch %" PRId64 ". Time since last GC %" PRIu64 " microseconds", epoch, timeStartUs - lastGCTimestampUs_);
-    auto graySet = collectRootSet();
+    collectRootSet(graySet_);
     auto timeRootSetUs = konan::getTimeMicros();
     // Can be unsafe, because we've stopped the world.
 
     auto objectsCountBefore = objectFactory_.GetSizeUnsafe();
     RuntimeLogInfo(
-            {kTagGC}, "Collected root set of size %zu in %" PRIu64 " microseconds", graySet.size(),
+            {kTagGC}, "Collected root set of size %zu in %" PRIu64 " microseconds", graySet_.size(),
             timeRootSetUs - timeSuspendUs);
-    auto markStats = gc::Mark<MarkTraits>(std::move(graySet));
+    auto markStats = gc::Mark<MarkTraits>(graySet_);
     auto timeMarkUs = konan::getTimeMicros();
     RuntimeLogDebug({kTagGC}, "Marked %zu objects in %" PRIu64 " microseconds. Processed %zu duplicate entries in the gray set", markStats.aliveHeapSet, timeMarkUs - timeRootSetUs, markStats.duplicateEntries);
     scheduler.gcData().UpdateAliveSetBytes(markStats.aliveHeapSetBytes);

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

@@ -88,6 +88,8 @@ private:
     GCStateHolder state_;
     ScopedThread gcThread_;
     KStdUniquePtr<FinalizerProcessor> finalizerProcessor_;
+
+    KStdVector<ObjHeader*> graySet_;
 };
 
 } // namespace gc

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

@@ -13,8 +13,8 @@
 
 using namespace kotlin;
 
-KStdVector<ObjHeader*> kotlin::gc::collectRootSet() {
-    KStdVector<ObjHeader*> graySet;
+void kotlin::gc::collectRootSet(KStdVector<ObjHeader*>& graySet) {
+    graySet.clear();
     for (auto& thread : mm::GlobalData::Instance().threadRegistry().LockForIter()) {
         // TODO: Maybe it's more efficient to do by the suspending thread?
         thread.Publish();
@@ -53,5 +53,4 @@ KStdVector<ObjHeader*> kotlin::gc::collectRootSet() {
         }
     }
     RuntimeLogDebug({kTagGC}, "Collected global root set global=%zu stableRef=%zu", global, stableRef);
-    return graySet;
 }

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

@@ -28,7 +28,7 @@ struct MarkStats {
 
 // TODO: Because of `graySet` this implementation may allocate heap memory during GC.
 template <typename Traits>
-MarkStats Mark(KStdVector<ObjHeader*> graySet) noexcept {
+MarkStats Mark(KStdVector<ObjHeader*>& graySet) noexcept {
     MarkStats stats;
     while (!graySet.empty()) {
         ObjHeader* top = graySet.back();
@@ -111,7 +111,7 @@ typename Traits::ObjectFactory::FinalizerQueue Sweep(typename Traits::ObjectFact
     return Sweep<Traits>(iter);
 }
 
-KStdVector<ObjHeader*> collectRootSet();
+void collectRootSet(KStdVector<ObjHeader*>& graySet);
 
 } // namespace gc
 } // namespace kotlin

kotlin-native/runtime/src/gc/common/cpp/MarkAndSweepUtilsMarkTest.cpp

@@ -147,7 +147,7 @@ public:
     gc::MarkStats Mark(std::initializer_list<std::reference_wrapper<BaseObject>> graySet) {
         KStdVector<ObjHeader*> objects;
         for (auto& object : graySet) objects.push_back(object.get().GetObjHeader());
-        return gc::Mark<ScopedMarkTraits>(std::move(objects));
+        return gc::Mark<ScopedMarkTraits>(objects);
     }
 
 private:

kotlin-native/runtime/src/gc/stms/cpp/SameThreadMarkAndSweep.cpp

@@ -104,6 +104,7 @@ NO_INLINE void gc::SameThreadMarkAndSweep::ThreadData::SafePointSlowPath(Safepoi
 gc::SameThreadMarkAndSweep::SameThreadMarkAndSweep(
         mm::ObjectFactory<SameThreadMarkAndSweep>& objectFactory, GCScheduler& gcScheduler) noexcept :
     objectFactory_(objectFactory), gcScheduler_(gcScheduler) {
+    graySet_.reserve(1000);
     gcScheduler_.SetScheduleGC([]() {
         // TODO: CMS is also responsible for avoiding scheduling while GC hasn't started running.
         //       Investigate, if it's possible to move this logic into the scheduler.
@@ -142,15 +143,15 @@ bool gc::SameThreadMarkAndSweep::PerformFullGC() noexcept {
 
         RuntimeLogInfo(
                 {kTagGC}, "Started GC epoch %zu. Time since last GC %" PRIu64 " microseconds", epoch_, timeStartUs - lastGCTimestampUs_);
-        auto graySet = collectRootSet();
+        collectRootSet(graySet_);
         auto timeRootSetUs = konan::getTimeMicros();
         // Can be unsafe, because we've stopped the world.
         auto objectsCountBefore = objectFactory_.GetSizeUnsafe();
 
         RuntimeLogInfo(
-                {kTagGC}, "Collected root set of size %zu in %" PRIu64 " microseconds", graySet.size(),
+                {kTagGC}, "Collected root set of size %zu in %" PRIu64 " microseconds", graySet_.size(),
                 timeRootSetUs - timeSuspendUs);
-        auto markStats = gc::Mark<MarkTraits>(std::move(graySet));
+        auto markStats = gc::Mark<MarkTraits>(graySet_);
         auto timeMarkUs = konan::getTimeMicros();
         RuntimeLogDebug({kTagGC}, "Marked %zu objects in %" PRIu64 " microseconds. Processed %zu duplicate entries in the gray set", markStats.aliveHeapSet, timeMarkUs - timeRootSetUs, markStats.duplicateEntries);
         scheduler.gcData().UpdateAliveSetBytes(markStats.aliveHeapSetBytes);

kotlin-native/runtime/src/gc/stms/cpp/SameThreadMarkAndSweep.hpp

@@ -85,6 +85,8 @@ private:
 
     mm::ObjectFactory<SameThreadMarkAndSweep>& objectFactory_;
     GCScheduler& gcScheduler_;
+
+    KStdVector<ObjHeader*> graySet_;
 };
 
 namespace internal {