cppgc: Remove StatsCollector dependency on HeapBase

Bug: chromium:1056170
Change-Id: I561166a7f1be658c5c35aa1caf8dbbbd2d720ab3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2692815
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Auto-Submit: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72754}

src/heap/cppgc-js/cpp-heap.cc

@@ -296,8 +296,8 @@ bool CppHeap::AdvanceTracing(double deadline_in_ms) {
   // accounting since this scope is also accounted under an outer v8 scope.
   // Make sure to only account this scope once.
   cppgc::internal::StatsCollector::EnabledScope stats_scope(
-      AsBase(), in_atomic_pause_
-                    ? cppgc::internal::StatsCollector::kAtomicMark
+      stats_collector(),
+      in_atomic_pause_ ? cppgc::internal::StatsCollector::kAtomicMark
                        : cppgc::internal::StatsCollector::kIncrementalMark);
   const v8::base::TimeDelta deadline =
       in_atomic_pause_ ? v8::base::TimeDelta::Max()
@@ -316,7 +316,7 @@ bool CppHeap::IsTracingDone() { return marking_done_; }
 void CppHeap::EnterFinalPause(EmbedderStackState stack_state) {
   CHECK(!in_disallow_gc_scope());
   cppgc::internal::StatsCollector::EnabledScope stats_scope(
-      AsBase(), cppgc::internal::StatsCollector::kAtomicMark);
+      stats_collector(), cppgc::internal::StatsCollector::kAtomicMark);
   in_atomic_pause_ = true;
   if (override_stack_state_) {
     stack_state = *override_stack_state_;
@@ -333,7 +333,7 @@ void CppHeap::TraceEpilogue(TraceSummary* trace_summary) {
   CHECK(marking_done_);
   {
     cppgc::internal::StatsCollector::EnabledScope stats_scope(
-        AsBase(), cppgc::internal::StatsCollector::kAtomicMark);
+        stats_collector(), cppgc::internal::StatsCollector::kAtomicMark);
     cppgc::subtle::DisallowGarbageCollectionScope disallow_gc_scope(*this);
     marker_->LeaveAtomicPause();
   }

src/heap/cppgc/compactor.cc

@@ -484,7 +484,7 @@ bool Compactor::CancelIfShouldNotCompact(
 Compactor::CompactableSpaceHandling Compactor::CompactSpacesIfEnabled() {
   if (!is_enabled_) return CompactableSpaceHandling::kSweep;
 
-  StatsCollector::DisabledScope stats_scope(*heap_.heap(),
+  StatsCollector::DisabledScope stats_scope(heap_.heap()->stats_collector(),
                                             StatsCollector::kAtomicCompact);
 
   MovableReferences movable_references(*heap_.heap());

src/heap/cppgc/concurrent-marker.cc

@@ -73,7 +73,8 @@ ConcurrentMarkingTask::ConcurrentMarkingTask(
 
 void ConcurrentMarkingTask::Run(JobDelegate* job_delegate) {
   StatsCollector::EnabledConcurrentScope stats_scope(
-      concurrent_marker_.heap(), StatsCollector::kConcurrentMark);
+      concurrent_marker_.heap().stats_collector(),
+      StatsCollector::kConcurrentMark);
 
   if (!HasWorkForConcurrentMarking(concurrent_marker_.marking_worklists()))
     return;
@@ -150,7 +151,7 @@ void ConcurrentMarkingTask::ProcessWorklists(
 
     {
       StatsCollector::DisabledConcurrentScope stats_scope(
-          concurrent_marker_.heap(),
+          concurrent_marker_.heap().stats_collector(),
           StatsCollector::kConcurrentMarkProcessEphemerons);
       if (!DrainWorklistWithYielding(
               job_delegate, concurrent_marking_state,

src/heap/cppgc/heap-base.cc

@@ -68,8 +68,8 @@ HeapBase::HeapBase(
       page_backend_(
           std::make_unique<PageBackend>(platform_->GetPageAllocator())),
 #endif
-      stats_collector_(
-          std::make_unique<StatsCollector>(std::move(histogram_recorder))),
+      stats_collector_(std::make_unique<StatsCollector>(
+          std::move(histogram_recorder), platform_.get())),
       stack_(std::make_unique<heap::base::Stack>(
           v8::base::Stack::GetStackStart())),
       prefinalizer_handler_(std::make_unique<PreFinalizerHandler>(*this)),

src/heap/cppgc/heap.cc

@@ -209,7 +209,7 @@ void Heap::DisableHeapGrowingForTesting() { growing_.DisableForTesting(); }
 void Heap::FinalizeIncrementalGarbageCollectionIfNeeded(
     Config::StackState stack_state) {
   StatsCollector::EnabledScope stats_scope(
-      *this, StatsCollector::kMarkIncrementalFinalize);
+      stats_collector(), StatsCollector::kMarkIncrementalFinalize);
   FinalizeGarbageCollection(stack_state);
 }
 

src/heap/cppgc/marker.cc

@@ -63,7 +63,7 @@ void VisitRememberedSlots(HeapBase& heap,
                           MutatorMarkingState& mutator_marking_state) {
 #if defined(CPPGC_YOUNG_GENERATION)
   StatsCollector::EnabledScope stats_scope(
-      heap, StatsCollector::kMarkVisitRememberedSets);
+      heap.stats_collector(), StatsCollector::kMarkVisitRememberedSets);
   for (void* slot : heap.remembered_slots()) {
     auto& slot_header = BasePage::FromInnerAddress(&heap, slot)
                             ->ObjectHeaderFromInnerAddress(slot);
@@ -151,7 +151,7 @@ MarkerBase::IncrementalMarkingTask::Post(cppgc::TaskRunner* runner,
 void MarkerBase::IncrementalMarkingTask::Run() {
   if (handle_.IsCanceled()) return;
 
-  StatsCollector::EnabledScope stats_scope(marker_->heap(),
+  StatsCollector::EnabledScope stats_scope(marker_->heap().stats_collector(),
                                            StatsCollector::kIncrementalMark);
 
   if (marker_->IncrementalMarkingStep(stack_state_)) {
@@ -204,7 +204,8 @@ MarkerBase::~MarkerBase() {
 void MarkerBase::StartMarking() {
   DCHECK(!is_marking_started_);
   StatsCollector::EnabledScope stats_scope(
-      heap(), config_.marking_type == MarkingConfig::MarkingType::kAtomic
+      heap().stats_collector(),
+      config_.marking_type == MarkingConfig::MarkingType::kAtomic
           ? StatsCollector::kAtomicMark
           : StatsCollector::kIncrementalMark);
 
@@ -214,7 +215,7 @@ void MarkerBase::StartMarking() {
   is_marking_started_ = true;
   if (EnterIncrementalMarkingIfNeeded(config_, heap())) {
     StatsCollector::EnabledScope stats_scope(
-        heap(), StatsCollector::kMarkIncrementalStart);
+        heap().stats_collector(), StatsCollector::kMarkIncrementalStart);
 
     // Performing incremental or concurrent marking.
     schedule_.NotifyIncrementalMarkingStart();
@@ -230,7 +231,7 @@ void MarkerBase::StartMarking() {
 }
 
 void MarkerBase::EnterAtomicPause(MarkingConfig::StackState stack_state) {
-  StatsCollector::EnabledScope stats_scope(heap(),
+  StatsCollector::EnabledScope stats_scope(heap().stats_collector(),
                                            StatsCollector::kMarkAtomicPrologue);
 
   if (ExitIncrementalMarkingIfNeeded(config_, heap())) {
@@ -260,7 +261,7 @@ void MarkerBase::EnterAtomicPause(MarkingConfig::StackState stack_state) {
 }
 
 void MarkerBase::LeaveAtomicPause() {
-  StatsCollector::EnabledScope stats_scope(heap(),
+  StatsCollector::EnabledScope stats_scope(heap().stats_collector(),
                                            StatsCollector::kMarkAtomicEpilogue);
   DCHECK(!incremental_marking_handle_);
   ResetRememberedSet(heap());
@@ -278,7 +279,8 @@ void MarkerBase::LeaveAtomicPause() {
 
 void MarkerBase::FinishMarking(MarkingConfig::StackState stack_state) {
   DCHECK(is_marking_started_);
-  StatsCollector::EnabledScope stats_scope(heap(), StatsCollector::kAtomicMark);
+  StatsCollector::EnabledScope stats_scope(heap().stats_collector(),
+                                           StatsCollector::kAtomicMark);
   EnterAtomicPause(stack_state);
   CHECK(AdvanceMarkingWithLimits(v8::base::TimeDelta::Max(), SIZE_MAX));
   mutator_marking_state_.Publish();
@@ -288,7 +290,7 @@ void MarkerBase::FinishMarking(MarkingConfig::StackState stack_state) {
 void MarkerBase::ProcessWeakness() {
   DCHECK_EQ(MarkingConfig::MarkingType::kAtomic, config_.marking_type);
 
-  StatsCollector::DisabledScope stats_scope(heap(),
+  StatsCollector::DisabledScope stats_scope(heap().stats_collector(),
                                             StatsCollector::kAtomicWeak);
 
   heap().GetWeakPersistentRegion().Trace(&visitor());
@@ -310,7 +312,7 @@ void MarkerBase::ProcessWeakness() {
 }
 
 void MarkerBase::VisitRoots(MarkingConfig::StackState stack_state) {
-  StatsCollector::EnabledScope stats_scope(heap(),
+  StatsCollector::EnabledScope stats_scope(heap().stats_collector(),
                                            StatsCollector::kMarkVisitRoots);
 
   // Reset LABs before scanning roots. LABs are cleared to allow
@@ -320,12 +322,13 @@ void MarkerBase::VisitRoots(MarkingConfig::StackState stack_state) {
   {
     {
       StatsCollector::DisabledScope inner_stats_scope(
-          heap(), StatsCollector::kMarkVisitPersistents);
+          heap().stats_collector(), StatsCollector::kMarkVisitPersistents);
       heap().GetStrongPersistentRegion().Trace(&visitor());
     }
     if (config_.marking_type == MarkingConfig::MarkingType::kAtomic) {
       StatsCollector::DisabledScope inner_stats_scope(
-          heap(), StatsCollector::kMarkVisitCrossThreadPersistents);
+          heap().stats_collector(),
+          StatsCollector::kMarkVisitCrossThreadPersistents);
       g_process_mutex.Get().AssertHeld();
       heap().GetStrongCrossThreadPersistentRegion().Trace(&visitor());
     }
@@ -333,7 +336,7 @@ void MarkerBase::VisitRoots(MarkingConfig::StackState stack_state) {
 
   if (stack_state != MarkingConfig::StackState::kNoHeapPointers) {
     StatsCollector::DisabledScope stack_stats_scope(
-        heap(), StatsCollector::kMarkVisitStack);
+        heap().stats_collector(), StatsCollector::kMarkVisitStack);
     heap().stack()->IteratePointers(&stack_visitor());
   }
   if (config_.collection_type == MarkingConfig::CollectionType::kMinor) {
@@ -379,8 +382,9 @@ bool MarkerBase::AdvanceMarkingWithLimits(v8::base::TimeDelta max_duration,
                            GetNextIncrementalStepDuration(schedule_, heap_);
     }
     StatsCollector::EnabledScope deadline_scope(
-        heap(), StatsCollector::kMarkTransitiveClosureWithDeadline,
-        "deadline_ms", max_duration.InMillisecondsF());
+        heap().stats_collector(),
+        StatsCollector::kMarkTransitiveClosureWithDeadline, "deadline_ms",
+        max_duration.InMillisecondsF());
     is_done = ProcessWorklistsWithDeadline(
         marked_bytes_limit, v8::base::TimeTicks::Now() + max_duration);
     if (with_schedule) {
@@ -404,7 +408,7 @@ bool MarkerBase::AdvanceMarkingWithLimits(v8::base::TimeDelta max_duration,
 bool MarkerBase::ProcessWorklistsWithDeadline(
     size_t marked_bytes_deadline, v8::base::TimeTicks time_deadline) {
   StatsCollector::EnabledScope stats_scope(
-      heap(), StatsCollector::kMarkTransitiveClosure);
+      heap().stats_collector(), StatsCollector::kMarkTransitiveClosure);
   do {
     if ((config_.marking_type == MarkingConfig::MarkingType::kAtomic) ||
         schedule_.ShouldFlushEphemeronPairs()) {
@@ -416,7 +420,7 @@ bool MarkerBase::ProcessWorklistsWithDeadline(
     // checks to guarantee the deadline is not exceeded.
     {
       StatsCollector::EnabledScope inner_scope(
-          heap(), StatsCollector::kMarkProcessBailOutObjects);
+          heap().stats_collector(), StatsCollector::kMarkProcessBailOutObjects);
       if (!DrainWorklistWithBytesAndTimeDeadline<kDefaultDeadlineCheckInterval /
                                                  5>(
               mutator_marking_state_, marked_bytes_deadline, time_deadline,
@@ -432,7 +436,8 @@ bool MarkerBase::ProcessWorklistsWithDeadline(
 
     {
       StatsCollector::EnabledScope inner_scope(
-          heap(), StatsCollector::kMarkProcessNotFullyconstructedWorklist);
+          heap().stats_collector(),
+          StatsCollector::kMarkProcessNotFullyconstructedWorklist);
       if (!DrainWorklistWithBytesAndTimeDeadline(
               mutator_marking_state_, marked_bytes_deadline, time_deadline,
               mutator_marking_state_
@@ -448,7 +453,8 @@ bool MarkerBase::ProcessWorklistsWithDeadline(
 
     {
       StatsCollector::EnabledScope inner_scope(
-          heap(), StatsCollector::kMarkProcessMarkingWorklist);
+          heap().stats_collector(),
+          StatsCollector::kMarkProcessMarkingWorklist);
       if (!DrainWorklistWithBytesAndTimeDeadline(
               mutator_marking_state_, marked_bytes_deadline, time_deadline,
               mutator_marking_state_.marking_worklist(),
@@ -466,7 +472,8 @@ bool MarkerBase::ProcessWorklistsWithDeadline(
 
     {
       StatsCollector::EnabledScope inner_scope(
-          heap(), StatsCollector::kMarkProcessWriteBarrierWorklist);
+          heap().stats_collector(),
+          StatsCollector::kMarkProcessWriteBarrierWorklist);
       if (!DrainWorklistWithBytesAndTimeDeadline(
               mutator_marking_state_, marked_bytes_deadline, time_deadline,
               mutator_marking_state_.write_barrier_worklist(),
@@ -481,7 +488,7 @@ bool MarkerBase::ProcessWorklistsWithDeadline(
 
     {
       StatsCollector::EnabledScope stats_scope(
-          heap(), StatsCollector::kMarkProcessEphemerons);
+          heap().stats_collector(), StatsCollector::kMarkProcessEphemerons);
       if (!DrainWorklistWithBytesAndTimeDeadline(
               mutator_marking_state_, marked_bytes_deadline, time_deadline,
               mutator_marking_state_.ephemeron_pairs_for_processing_worklist(),
@@ -498,7 +505,8 @@ bool MarkerBase::ProcessWorklistsWithDeadline(
 
 void MarkerBase::MarkNotFullyConstructedObjects() {
   StatsCollector::DisabledScope stats_scope(
-      heap(), StatsCollector::kMarkVisitNotFullyConstructedObjects);
+      heap().stats_collector(),
+      StatsCollector::kMarkVisitNotFullyConstructedObjects);
   std::unordered_set<HeapObjectHeader*> objects =
       mutator_marking_state_.not_fully_constructed_worklist().Extract();
   for (HeapObjectHeader* object : objects) {

src/heap/cppgc/marking-state.cc

@@ -6,6 +6,7 @@
 
 #include <unordered_set>
 
+#include "src/heap/cppgc/heap-base.h"
 #include "src/heap/cppgc/stats-collector.h"
 
 namespace cppgc {
@@ -22,7 +23,7 @@ void MutatorMarkingState::FlushNotFullyConstructedObjects() {
 
 void MutatorMarkingState::FlushDiscoveredEphemeronPairs() {
   StatsCollector::EnabledScope stats_scope(
-      heap_, StatsCollector::kMarkFlushEphemerons);
+      heap_.stats_collector(), StatsCollector::kMarkFlushEphemerons);
   discovered_ephemeron_pairs_worklist_.Publish();
   if (!discovered_ephemeron_pairs_worklist_.IsGlobalEmpty()) {
     ephemeron_pairs_for_processing_worklist_.Merge(

src/heap/cppgc/prefinalizer-handler.cc

@@ -49,7 +49,7 @@ void PreFinalizerHandler::RegisterPrefinalizer(PreFinalizer pre_finalizer) {
 
 void PreFinalizerHandler::InvokePreFinalizers() {
   StatsCollector::DisabledScope stats_scope(
-      heap_, StatsCollector::kSweepInvokePreFinalizers);
+      heap_.stats_collector(), StatsCollector::kSweepInvokePreFinalizers);
 
   DCHECK(CurrentThreadIsCreationThread());
   LivenessBroker liveness_broker = LivenessBrokerFactory::Create();

src/heap/cppgc/stats-collector.cc

@@ -17,8 +17,10 @@ namespace internal {
 constexpr size_t StatsCollector::kAllocationThresholdBytes;
 
 StatsCollector::StatsCollector(
-    std::unique_ptr<MetricRecorder> histogram_recorder)
-    : metric_recorder_(std::move(histogram_recorder)) {}
+    std::unique_ptr<MetricRecorder> histogram_recorder, Platform* platform)
+    : metric_recorder_(std::move(histogram_recorder)), platform_(platform) {
+  USE(platform_);
+}
 
 void StatsCollector::RegisterObserver(AllocationObserver* observer) {
   DCHECK_EQ(allocation_observers_.end(),

src/heap/cppgc/stats-collector.h

@@ -10,10 +10,10 @@
 
 #include <vector>
 
+#include "include/cppgc/platform.h"
 #include "src/base/macros.h"
 #include "src/base/platform/time.h"
 #include "src/heap/cppgc/garbage-collector.h"
-#include "src/heap/cppgc/heap-base.h"
 #include "src/heap/cppgc/metric-recorder.h"
 #include "src/heap/cppgc/trace-event.h"
 
@@ -154,9 +154,9 @@ class V8_EXPORT_PRIVATE StatsCollector final {
 
    public:
     template <typename... Args>
-    InternalScope(HeapBase& heap, ScopeIdType scope_id, Args... args)
-        : heap_(heap),
-          stats_collector_(heap_.stats_collector()),
+    InternalScope(StatsCollector* stats_collector, ScopeIdType scope_id,
+                  Args... args)
+        : stats_collector_(stats_collector),
           start_time_(v8::base::TimeTicks::Now()),
           scope_id_(scope_id) {
       DCHECK_LE(0, scope_id_);
@@ -203,7 +203,6 @@ class V8_EXPORT_PRIVATE StatsCollector final {
 
     inline void IncreaseScopeTime();
 
-    HeapBase& heap_;
     StatsCollector* const stats_collector_;
     v8::base::TimeTicks start_time_;
     const ScopeIdType scope_id_;
@@ -240,7 +239,7 @@ class V8_EXPORT_PRIVATE StatsCollector final {
   // reasonably interesting sizes.
   static constexpr size_t kAllocationThresholdBytes = 1024;
 
-  explicit StatsCollector(std::unique_ptr<MetricRecorder>);
+  StatsCollector(std::unique_ptr<MetricRecorder>, Platform*);
   StatsCollector(const StatsCollector&) = delete;
   StatsCollector& operator=(const StatsCollector&) = delete;
 
@@ -325,6 +324,8 @@ class V8_EXPORT_PRIVATE StatsCollector final {
   Event previous_;
 
   std::unique_ptr<MetricRecorder> metric_recorder_;
+
+  Platform* platform_;
 };
 
 template <typename Callback>

src/heap/cppgc/sweeper.cc

@@ -427,7 +427,7 @@ class ConcurrentSweepTask final : public cppgc::JobTask,
 
   void Run(cppgc::JobDelegate* delegate) final {
     StatsCollector::EnabledConcurrentScope stats_scope(
-        heap_, StatsCollector::kConcurrentSweep);
+        heap_.stats_collector(), StatsCollector::kConcurrentSweep);
 
     for (SpaceState& state : *states_) {
       while (auto page = state.unswept_pages.Pop()) {
@@ -531,7 +531,7 @@ class Sweeper::SweeperImpl final {
   ~SweeperImpl() { CancelSweepers(); }
 
   void Start(SweepingConfig config) {
-    StatsCollector::EnabledScope stats_scope(*heap_->heap(),
+    StatsCollector::EnabledScope stats_scope(heap_->heap()->stats_collector(),
                                              StatsCollector::kAtomicSweep);
     is_in_progress_ = true;
 #if DEBUG
@@ -558,10 +558,10 @@ class Sweeper::SweeperImpl final {
     // allocate new memory.
     if (is_sweeping_on_mutator_thread_) return false;
 
-    StatsCollector::EnabledScope stats_scope(*heap_->heap(),
+    StatsCollector::EnabledScope stats_scope(heap_->heap()->stats_collector(),
                                              StatsCollector::kIncrementalSweep);
     StatsCollector::EnabledScope inner_scope(
-        *heap_->heap(), StatsCollector::kSweepOnAllocation);
+        heap_->heap()->stats_collector(), StatsCollector::kSweepOnAllocation);
     MutatorThreadSweepingScope sweeping_in_progresss(*this);
 
     SpaceState& space_state = space_states_[space->index()];
@@ -597,8 +597,8 @@ class Sweeper::SweeperImpl final {
 
     {
       StatsCollector::EnabledScope stats_scope(
-          *heap_->heap(), StatsCollector::kIncrementalSweep);
-      StatsCollector::EnabledScope inner_scope(*heap_->heap(),
+          heap_->heap()->stats_collector(), StatsCollector::kIncrementalSweep);
+      StatsCollector::EnabledScope inner_scope(heap_->heap()->stats_collector(),
                                                StatsCollector::kSweepFinalize);
       if (concurrent_sweeper_handle_ && concurrent_sweeper_handle_->IsValid() &&
           concurrent_sweeper_handle_->UpdatePriorityEnabled()) {
@@ -698,14 +698,15 @@ class Sweeper::SweeperImpl final {
       bool sweep_complete;
       {
         StatsCollector::EnabledScope stats_scope(
-            *sweeper_->heap_->heap(), StatsCollector::kIncrementalSweep);
+            sweeper_->heap_->heap()->stats_collector(),
+            StatsCollector::kIncrementalSweep);
 
         MutatorThreadSweeper sweeper(&sweeper_->space_states_,
                                      sweeper_->platform_);
         {
           StatsCollector::EnabledScope stats_scope(
-              *sweeper_->heap_->heap(), StatsCollector::kSweepIdleStep,
-              "idleDeltaInSeconds",
+              sweeper_->heap_->heap()->stats_collector(),
+              StatsCollector::kSweepIdleStep, "idleDeltaInSeconds",
               (deadline_in_seconds -
                sweeper_->platform_->MonotonicallyIncreasingTime()));
 

src/heap/cppgc/trace-event.h

@@ -116,7 +116,7 @@ enum CategoryGroupEnabledFlags {
 #define INTERNAL_TRACE_EVENT_ADD(phase, category_group, name, flags, ...)    \
   DCHECK_NOT_NULL(name);                                                     \
   do {                                                                       \
-    cppgc::Platform* platform = heap_.platform();                            \
+    cppgc::Platform* platform = stats_collector_->platform_;                 \
     INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category_group);                  \
     if (INTERNAL_TRACE_EVENT_CATEGORY_GROUP_ENABLED_FOR_RECORDING_MODE()) {  \
       cppgc::internal::AddTraceEvent(                                        \

test/unittests/heap/cppgc/heap-growing-unittest.cc

@@ -60,7 +60,8 @@ void FakeAllocate(StatsCollector* stats_collector, size_t bytes) {
 }  // namespace
 
 TEST(HeapGrowingTest, ConservativeGCInvoked) {
-  StatsCollector stats_collector(nullptr /* metric_recorder */);
+  StatsCollector stats_collector(nullptr /* metric_recorder */,
+                                 nullptr /* platform */);
   MockGarbageCollector gc;
   cppgc::Heap::ResourceConstraints constraints;
   // Force GC at the first update.
@@ -73,7 +74,8 @@ TEST(HeapGrowingTest, ConservativeGCInvoked) {
 }
 
 TEST(HeapGrowingTest, InitialHeapSize) {
-  StatsCollector stats_collector(nullptr /* metric_recorder */);
+  StatsCollector stats_collector(nullptr /* metric_recorder */,
+                                 nullptr /* platform */);
   MockGarbageCollector gc;
   cppgc::Heap::ResourceConstraints constraints;
   // Use larger size to avoid running into small heap optimizations.
@@ -90,7 +92,8 @@ TEST(HeapGrowingTest, InitialHeapSize) {
 TEST(HeapGrowingTest, ConstantGrowingFactor) {
   // Use larger size to avoid running into small heap optimizations.
   constexpr size_t kObjectSize = 10 * HeapGrowing::kMinLimitIncrease;
-  StatsCollector stats_collector(nullptr /* metric_recorder */);
+  StatsCollector stats_collector(nullptr /* metric_recorder */,
+                                 nullptr /* platform */);
   FakeGarbageCollector gc(&stats_collector);
   cppgc::Heap::ResourceConstraints constraints;
   // Force GC at the first update.
@@ -108,7 +111,8 @@ TEST(HeapGrowingTest, ConstantGrowingFactor) {
 TEST(HeapGrowingTest, SmallHeapGrowing) {
   // Larger constant to avoid running into special handling for smaller heaps.
   constexpr size_t kLargeAllocation = 100 * kMB;
-  StatsCollector stats_collector(nullptr /* metric_recorder */);
+  StatsCollector stats_collector(nullptr /* metric_recorder */,
+                                 nullptr /* platform */);
   FakeGarbageCollector gc(&stats_collector);
   cppgc::Heap::ResourceConstraints constraints;
   // Force GC at the first update.
@@ -124,7 +128,8 @@ TEST(HeapGrowingTest, SmallHeapGrowing) {
 }
 
 TEST(HeapGrowingTest, IncrementalGCStarted) {
-  StatsCollector stats_collector(nullptr /* metric_recorder */);
+  StatsCollector stats_collector(nullptr /* metric_recorder */,
+                                 nullptr /* platform */);
   MockGarbageCollector gc;
   cppgc::Heap::ResourceConstraints constraints;
   HeapGrowing growing(&gc, &stats_collector, constraints,
@@ -137,7 +142,8 @@ TEST(HeapGrowingTest, IncrementalGCStarted) {
 }
 
 TEST(HeapGrowingTest, IncrementalGCFinalized) {
-  StatsCollector stats_collector(nullptr /* metric_recorder */);
+  StatsCollector stats_collector(nullptr /* metric_recorder */,
+                                 nullptr /* platform */);
   MockGarbageCollector gc;
   cppgc::Heap::ResourceConstraints constraints;
   HeapGrowing growing(&gc, &stats_collector, constraints,

test/unittests/heap/cppgc/metric-recorder-unittest.cc

@@ -72,7 +72,8 @@ TEST_F(MetricRecorderTest, IncrementalScopesReportedImmediately) {
   {
     EXPECT_EQ(0u, MetricRecorderImpl::CppGCMainThreadIncrementalMark_callcount);
     {
-      StatsCollector::EnabledScope scope(*Heap::From(GetHeap()),
+      StatsCollector::EnabledScope scope(
+          Heap::From(GetHeap())->stats_collector(),
           StatsCollector::kIncrementalMark);
       scope.DecreaseStartTimeForTesting(
           v8::base::TimeDelta::FromMilliseconds(1));
@@ -86,7 +87,8 @@ TEST_F(MetricRecorderTest, IncrementalScopesReportedImmediately) {
     EXPECT_EQ(0u,
               MetricRecorderImpl::CppGCMainThreadIncrementalSweep_callcount);
     {
-      StatsCollector::EnabledScope scope(*Heap::From(GetHeap()),
+      StatsCollector::EnabledScope scope(
+          Heap::From(GetHeap())->stats_collector(),
           StatsCollector::kIncrementalSweep);
       scope.DecreaseStartTimeForTesting(
           v8::base::TimeDelta::FromMilliseconds(1));
@@ -107,28 +109,30 @@ TEST_F(MetricRecorderTest, NonIncrementlaScopesNotReportedImmediately) {
   MetricRecorderImpl::CppGCMainThreadIncrementalSweep_callcount = 0u;
   StartGC();
   {
-    StatsCollector::EnabledScope scope(*Heap::From(GetHeap()),
+    StatsCollector::EnabledScope scope(Heap::From(GetHeap())->stats_collector(),
                                        StatsCollector::kAtomicMark);
   }
   {
-    StatsCollector::EnabledScope scope(*Heap::From(GetHeap()),
+    StatsCollector::EnabledScope scope(Heap::From(GetHeap())->stats_collector(),
                                        StatsCollector::kAtomicWeak);
   }
   {
-    StatsCollector::EnabledScope scope(*Heap::From(GetHeap()),
+    StatsCollector::EnabledScope scope(Heap::From(GetHeap())->stats_collector(),
                                        StatsCollector::kAtomicCompact);
   }
   {
-    StatsCollector::EnabledScope scope(*Heap::From(GetHeap()),
+    StatsCollector::EnabledScope scope(Heap::From(GetHeap())->stats_collector(),
                                        StatsCollector::kAtomicSweep);
   }
   {
     StatsCollector::EnabledConcurrentScope scope(
-        *Heap::From(GetHeap()), StatsCollector::kConcurrentMark);
+        Heap::From(GetHeap())->stats_collector(),
+        StatsCollector::kConcurrentMark);
   }
   {
     StatsCollector::EnabledConcurrentScope scope(
-        *Heap::From(GetHeap()), StatsCollector::kConcurrentSweep);
+        Heap::From(GetHeap())->stats_collector(),
+        StatsCollector::kConcurrentSweep);
   }
   EXPECT_EQ(0u, MetricRecorderImpl::CppGCMainThreadIncrementalMark_callcount);
   EXPECT_EQ(0u, MetricRecorderImpl::CppGCMainThreadIncrementalSweep_callcount);
@@ -152,50 +156,52 @@ TEST_F(MetricRecorderTest, CycleEndHistogramReportsCorrectValues) {
   EndGC(1000);
   StartGC();
   {
-    StatsCollector::EnabledScope scope(*Heap::From(GetHeap()),
+    StatsCollector::EnabledScope scope(Heap::From(GetHeap())->stats_collector(),
                                        StatsCollector::kIncrementalMark);
     scope.DecreaseStartTimeForTesting(
         v8::base::TimeDelta::FromMilliseconds(10));
   }
   {
-    StatsCollector::EnabledScope scope(*Heap::From(GetHeap()),
+    StatsCollector::EnabledScope scope(Heap::From(GetHeap())->stats_collector(),
                                        StatsCollector::kIncrementalSweep);
     scope.DecreaseStartTimeForTesting(
         v8::base::TimeDelta::FromMilliseconds(20));
   }
   {
-    StatsCollector::EnabledScope scope(*Heap::From(GetHeap()),
+    StatsCollector::EnabledScope scope(Heap::From(GetHeap())->stats_collector(),
                                        StatsCollector::kAtomicMark);
     scope.DecreaseStartTimeForTesting(
         v8::base::TimeDelta::FromMilliseconds(30));
   }
   {
-    StatsCollector::EnabledScope scope(*Heap::From(GetHeap()),
+    StatsCollector::EnabledScope scope(Heap::From(GetHeap())->stats_collector(),
                                        StatsCollector::kAtomicWeak);
     scope.DecreaseStartTimeForTesting(
         v8::base::TimeDelta::FromMilliseconds(50));
   }
   {
-    StatsCollector::EnabledScope scope(*Heap::From(GetHeap()),
+    StatsCollector::EnabledScope scope(Heap::From(GetHeap())->stats_collector(),
                                        StatsCollector::kAtomicCompact);
     scope.DecreaseStartTimeForTesting(
         v8::base::TimeDelta::FromMilliseconds(60));
   }
   {
-    StatsCollector::EnabledScope scope(*Heap::From(GetHeap()),
+    StatsCollector::EnabledScope scope(Heap::From(GetHeap())->stats_collector(),
                                        StatsCollector::kAtomicSweep);
     scope.DecreaseStartTimeForTesting(
         v8::base::TimeDelta::FromMilliseconds(70));
   }
   {
     StatsCollector::EnabledConcurrentScope scope(
-        *Heap::From(GetHeap()), StatsCollector::kConcurrentMark);
+        Heap::From(GetHeap())->stats_collector(),
+        StatsCollector::kConcurrentMark);
     scope.DecreaseStartTimeForTesting(
         v8::base::TimeDelta::FromMilliseconds(80));
   }
   {
     StatsCollector::EnabledConcurrentScope scope(
-        *Heap::From(GetHeap()), StatsCollector::kConcurrentSweep);
+        Heap::From(GetHeap())->stats_collector(),
+        StatsCollector::kConcurrentSweep);
     scope.DecreaseStartTimeForTesting(
         v8::base::TimeDelta::FromMilliseconds(100));
   }

test/unittests/heap/cppgc/stats-collector-scopes-unittest.cc

@@ -109,7 +109,8 @@ TEST_F(CppgcTracingScopesTest, DisabledScope) {
   ResetDelegatingTracingController();
   {
     StatsCollector::DisabledScope scope(
-        *Heap::From(GetHeap()), StatsCollector::kMarkProcessMarkingWorklist);
+        Heap::From(GetHeap())->stats_collector(),
+        StatsCollector::kMarkProcessMarkingWorklist);
   }
   EXPECT_EQ(0u, DelegatingTracingControllerImpl::AddTraceEvent_callcount);
   EndGC();
@@ -121,7 +122,8 @@ TEST_F(CppgcTracingScopesTest, EnabledScope) {
     ResetDelegatingTracingController("CppGC.MarkProcessMarkingWorklist");
     {
       StatsCollector::EnabledScope scope(
-          *Heap::From(GetHeap()), StatsCollector::kMarkProcessMarkingWorklist);
+          Heap::From(GetHeap())->stats_collector(),
+          StatsCollector::kMarkProcessMarkingWorklist);
     }
     EXPECT_EQ(2u, DelegatingTracingControllerImpl::AddTraceEvent_callcount);
     EndGC();
@@ -131,7 +133,7 @@ TEST_F(CppgcTracingScopesTest, EnabledScope) {
     ResetDelegatingTracingController("CppGC.MarkProcessWriteBarrierWorklist");
     {
       StatsCollector::EnabledScope scope(
-          *Heap::From(GetHeap()),
+          Heap::From(GetHeap())->stats_collector(),
           StatsCollector::kMarkProcessWriteBarrierWorklist);
     }
     EXPECT_EQ(2u, DelegatingTracingControllerImpl::AddTraceEvent_callcount);
@@ -146,7 +148,8 @@ TEST_F(CppgcTracingScopesTest, EnabledScopeWithArgs) {
     ResetDelegatingTracingController();
     {
       StatsCollector::EnabledScope scope(
-          *Heap::From(GetHeap()), StatsCollector::kMarkProcessMarkingWorklist);
+          Heap::From(GetHeap())->stats_collector(),
+          StatsCollector::kMarkProcessMarkingWorklist);
     }
     EXPECT_EQ(2, DelegatingTracingControllerImpl::stored_num_args);
     EndGC();
@@ -156,8 +159,8 @@ TEST_F(CppgcTracingScopesTest, EnabledScopeWithArgs) {
     ResetDelegatingTracingController();
     {
       StatsCollector::EnabledScope scope(
-          *Heap::From(GetHeap()), StatsCollector::kMarkProcessMarkingWorklist,
-          "arg1", 1);
+          Heap::From(GetHeap())->stats_collector(),
+          StatsCollector::kMarkProcessMarkingWorklist, "arg1", 1);
     }
     EXPECT_EQ(3, DelegatingTracingControllerImpl::stored_num_args);
     EndGC();
@@ -167,8 +170,8 @@ TEST_F(CppgcTracingScopesTest, EnabledScopeWithArgs) {
     ResetDelegatingTracingController();
     {
       StatsCollector::EnabledScope scope(
-          *Heap::From(GetHeap()), StatsCollector::kMarkProcessMarkingWorklist,
-          "arg1", 1, "arg2", 2);
+          Heap::From(GetHeap())->stats_collector(),
+          StatsCollector::kMarkProcessMarkingWorklist, "arg1", 1, "arg2", 2);
     }
     EXPECT_EQ(4, DelegatingTracingControllerImpl::stored_num_args);
     EndGC();
@@ -181,8 +184,9 @@ TEST_F(CppgcTracingScopesTest, CheckScopeArgs) {
     ResetDelegatingTracingController();
     {
       StatsCollector::EnabledScope scope(
-          *Heap::From(GetHeap()), StatsCollector::kMarkProcessMarkingWorklist,
-          "uint_arg", 13u, "bool_arg", false);
+          Heap::From(GetHeap())->stats_collector(),
+          StatsCollector::kMarkProcessMarkingWorklist, "uint_arg", 13u,
+          "bool_arg", false);
     }
     FindArgument("uint_arg", TRACE_VALUE_TYPE_UINT, 13);
     FindArgument("bool_arg", TRACE_VALUE_TYPE_BOOL, false);
@@ -193,8 +197,9 @@ TEST_F(CppgcTracingScopesTest, CheckScopeArgs) {
     ResetDelegatingTracingController();
     {
       StatsCollector::EnabledScope scope(
-          *Heap::From(GetHeap()), StatsCollector::kMarkProcessMarkingWorklist,
-          "neg_int_arg", -5, "pos_int_arg", 7);
+          Heap::From(GetHeap())->stats_collector(),
+          StatsCollector::kMarkProcessMarkingWorklist, "neg_int_arg", -5,
+          "pos_int_arg", 7);
     }
     FindArgument("neg_int_arg", TRACE_VALUE_TYPE_INT, -5);
     FindArgument("pos_int_arg", TRACE_VALUE_TYPE_INT, 7);
@@ -207,8 +212,9 @@ TEST_F(CppgcTracingScopesTest, CheckScopeArgs) {
     const char* string_value = "test";
     {
       StatsCollector::EnabledScope scope(
-          *Heap::From(GetHeap()), StatsCollector::kMarkProcessMarkingWorklist,
-          "string_arg", string_value, "double_arg", double_value);
+          Heap::From(GetHeap())->stats_collector(),
+          StatsCollector::kMarkProcessMarkingWorklist, "string_arg",
+          string_value, "double_arg", double_value);
     }
     FindArgument("string_arg", TRACE_VALUE_TYPE_STRING,
                  reinterpret_cast<uint64_t>(string_value));
@@ -245,7 +251,7 @@ TEST_F(CppgcTracingScopesTest, TestIndividualScopes) {
     DelegatingTracingControllerImpl::check_expectations = false;
     {
       StatsCollector::EnabledScope scope(
-          *Heap::From(GetHeap()),
+          Heap::From(GetHeap())->stats_collector(),
           static_cast<StatsCollector::ScopeId>(scope_id));
       v8::base::TimeTicks time = v8::base::TimeTicks::Now();
       while (time == v8::base::TimeTicks::Now()) {
@@ -278,7 +284,7 @@ TEST_F(CppgcTracingScopesTest, TestIndividualConcurrentScopes) {
     DelegatingTracingControllerImpl::check_expectations = false;
     {
       StatsCollector::EnabledConcurrentScope scope(
-          *Heap::From(GetHeap()),
+          Heap::From(GetHeap())->stats_collector(),
           static_cast<StatsCollector::ConcurrentScopeId>(scope_id));
       v8::base::TimeTicks time = v8::base::TimeTicks::Now();
       while (time == v8::base::TimeTicks::Now()) {

test/unittests/heap/cppgc/stats-collector-unittest.cc

@@ -18,7 +18,8 @@ constexpr size_t kMinReportedSize = StatsCollector::kAllocationThresholdBytes;
 
 class StatsCollectorTest : public ::testing::Test {
  public:
-  StatsCollectorTest() : stats(nullptr /* metric_recorder */) {}
+  StatsCollectorTest()
+      : stats(nullptr /* metric_recorder */, nullptr /* platform */) {}
 
   void FakeAllocate(size_t bytes) {
     stats.NotifyAllocation(bytes);