Revert "[heap] Remove sweeping state in incremental marking"

This reverts commit 7f29c48e.

Reason for revert: Causing TSAN failures on test bots.

Original change's description:
> [heap] Remove sweeping state in incremental marking
> 
> Remove the SWEEPING state from incremental marking. Sweeping is now
> always completed when starting incremental marking. Before this change
> there needed to be a safepoint each for starting marking and completing
> sweeping. Now both happens within a single safepoint.
> 
> Bug: v8:10315
> Change-Id: Iad2835554865f2de24376372affe9a98992d1fa0
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2190419
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#67678}

TBR=ulan@chromium.org,dinfuehr@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: v8:10315
Change-Id: I5e76990155cf7aeee3ecefe5e37f9028cb188a00
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2192658Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67699}

src/heap/incremental-marking.cc

@@ -292,17 +292,16 @@ void IncrementalMarking::Start(GarbageCollectionReason gc_reason) {
     heap_->array_buffer_sweeper()->EnsureFinished();
   }
 
-  if (collector_->sweeping_in_progress()) {
-    TRACE_GC(heap_->tracer(), GCTracer::Scope::MC_INCREMENTAL_SWEEPING);
-    collector_->EnsureSweepingCompleted();
-#ifdef DEBUG
-    heap_->VerifyCountersAfterSweeping();
-#endif
+  if (!collector_->sweeping_in_progress()) {
+    StartMarking();
+  } else {
+    if (FLAG_trace_incremental_marking) {
+      heap()->isolate()->PrintWithTimestamp(
+          "[IncrementalMarking] Start sweeping.\n");
+    }
+    SetState(SWEEPING);
   }
 
-  CHECK(!collector_->sweeping_in_progress());
-  StartMarking();
-
   heap_->AddAllocationObserversToAllSpaces(&old_generation_observer_,
                                            &new_generation_observer_);
   incremental_marking_job()->Start(heap_);
@@ -956,6 +955,28 @@ StepResult IncrementalMarking::AdvanceWithDeadline(
   return Step(kStepSizeInMs, completion_action, step_origin);
 }
 
+void IncrementalMarking::FinalizeSweeping() {
+  DCHECK(state_ == SWEEPING);
+#ifdef DEBUG
+  // Enforce safepoint here such that background threads cannot allocate between
+  // completing sweeping and VerifyCountersAfterSweeping().
+  SafepointScope scope(heap());
+#endif
+  if (collector_->sweeping_in_progress() &&
+      (!FLAG_concurrent_sweeping ||
+       !collector_->sweeper()->AreSweeperTasksRunning())) {
+    collector_->EnsureSweepingCompleted();
+  }
+  if (!collector_->sweeping_in_progress()) {
+#ifdef DEBUG
+    heap_->VerifyCountersAfterSweeping();
+#else
+    SafepointScope scope(heap());
+#endif
+    StartMarking();
+  }
+}
+
 size_t IncrementalMarking::StepSizeToKeepUpWithAllocations() {
   // Update bytes_allocated_ based on the allocation counter.
   size_t current_counter = heap_->OldGenerationAllocationCounter();
@@ -1046,7 +1067,7 @@ void IncrementalMarking::AdvanceOnAllocation() {
   // Code using an AlwaysAllocateScope assumes that the GC state does not
   // change; that implies that no marking steps must be performed.
   if (heap_->gc_state() != Heap::NOT_IN_GC || !FLAG_incremental_marking ||
-      state_ != MARKING || heap_->always_allocate()) {
+      (state_ != SWEEPING && state_ != MARKING) || heap_->always_allocate()) {
     return;
   }
   HistogramTimerScope incremental_marking_scope(
@@ -1062,6 +1083,11 @@ StepResult IncrementalMarking::Step(double max_step_size_in_ms,
                                     StepOrigin step_origin) {
   double start = heap_->MonotonicallyIncreasingTimeInMs();
 
+  if (state_ == SWEEPING) {
+    TRACE_GC(heap_->tracer(), GCTracer::Scope::MC_INCREMENTAL_SWEEPING);
+    FinalizeSweeping();
+  }
+
   StepResult combined_result = StepResult::kMoreWorkRemaining;
   size_t bytes_to_process = 0;
   size_t v8_bytes_processed = 0;

src/heap/incremental-marking.h

@@ -28,7 +28,7 @@ enum class StepResult {
 
 class V8_EXPORT_PRIVATE IncrementalMarking final {
  public:
-  enum State : uint8_t { STOPPED, MARKING, COMPLETE };
+  enum State : uint8_t { STOPPED, SWEEPING, MARKING, COMPLETE };
 
   enum CompletionAction { GC_VIA_STACK_GUARD, NO_GC_VIA_STACK_GUARD };
 
@@ -115,6 +115,8 @@ class V8_EXPORT_PRIVATE IncrementalMarking final {
 
   inline bool IsStopped() const { return state() == STOPPED; }
 
+  inline bool IsSweeping() const { return state() == SWEEPING; }
+
   inline bool IsMarking() const { return state() >= MARKING; }
 
   inline bool IsMarkingIncomplete() const { return state() == MARKING; }
@@ -165,6 +167,8 @@ class V8_EXPORT_PRIVATE IncrementalMarking final {
                                  CompletionAction completion_action,
                                  StepOrigin step_origin);
 
+  void FinalizeSweeping();
+
   StepResult Step(double max_step_size_in_ms, CompletionAction action,
                   StepOrigin step_origin);
 

src/heap/mark-compact.cc

@@ -847,6 +847,10 @@ void MarkCompactCollector::Prepare() {
     heap_->array_buffer_sweeper()->EnsureFinished();
   }
 
+  if (heap()->incremental_marking()->IsSweeping()) {
+    heap()->incremental_marking()->Stop();
+  }
+
   if (!was_marked_incrementally_) {
     {
       TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_MARK_EMBEDDER_PROLOGUE);

test/cctest/heap/heap-utils.cc

@@ -162,6 +162,9 @@ void SimulateIncrementalMarking(i::Heap* heap, bool force_completion) {
   if (collector->sweeping_in_progress()) {
     collector->EnsureSweepingCompleted();
   }
+  if (marking->IsSweeping()) {
+    marking->FinalizeSweeping();
+  }
   CHECK(marking->IsMarking() || marking->IsStopped() || marking->IsComplete());
   if (marking->IsStopped()) {
     heap->StartIncrementalMarking(i::Heap::kNoGCFlags,