Reland "cppgc-js: Add unittest for CollectCustomSpaceStatisticsAtLastGC"

This is a reland of 4f4b4f74

Original change's description:
> cppgc-js: Add unittest for CollectCustomSpaceStatisticsAtLastGC
>
> Drive-by: fix delayed task implementation in cpp-heap.cc.
>
> Bug: chromium:1056170
> Change-Id: Ie92d909056532047b378ebfafeb98273997e60e9
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2883618
> Commit-Queue: Omer Katz <omerkatz@chromium.org>
> Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#74530}

Bug: chromium:1056170
Change-Id: Ic3a7bb269e23acf728af57a9733600567659e76b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2897084
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74601}

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

@@ -522,14 +522,18 @@ class CollectCustomSpaceStatisticsAtLastGCTask final : public v8::Task {
 
   void Run() final {
     cppgc::internal::Sweeper& sweeper = heap_.sweeper();
-    if (sweeper.PerformSweepOnMutatorThread(kStepSizeMs.InSecondsF())) {
+    if (sweeper.PerformSweepOnMutatorThread(
+            heap_.platform()->MonotonicallyIncreasingTime() +
+            kStepSizeMs.InSecondsF())) {
+      // Sweeping is done.
+      DCHECK(!sweeper.IsSweepingInProgress());
+      ReportCustomSpaceStatistics(heap_.raw_heap(), std::move(custom_spaces_),
+                                  std::move(receiver_));
+    } else {
       heap_.platform()->GetForegroundTaskRunner()->PostDelayedTask(
           std::make_unique<CollectCustomSpaceStatisticsAtLastGCTask>(
               heap_, std::move(custom_spaces_), std::move(receiver_)),
           kTaskDelayMs.InSecondsF());
-    } else {
-      ReportCustomSpaceStatistics(heap_.raw_heap(), std::move(custom_spaces_),
-                                  std::move(receiver_));
     }
   }
 

test/unittests/heap/unified-heap-unittest.cc

@@ -2,15 +2,20 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <memory>
+
 #include "include/cppgc/allocation.h"
 #include "include/cppgc/garbage-collected.h"
 #include "include/cppgc/persistent.h"
 #include "include/cppgc/platform.h"
 #include "include/cppgc/testing.h"
+#include "include/libplatform/libplatform.h"
 #include "include/v8-cppgc.h"
 #include "include/v8.h"
 #include "src/api/api-inl.h"
+#include "src/base/platform/time.h"
 #include "src/heap/cppgc-js/cpp-heap.h"
+#include "src/heap/cppgc/heap-object-header.h"
 #include "src/heap/cppgc/sweeper.h"
 #include "src/objects/objects-inl.h"
 #include "test/unittests/heap/heap-utils.h"
@@ -191,3 +196,140 @@ TEST_F(UnifiedHeapDetachedTest, StandaloneTestingHeap) {
 
 }  // namespace internal
 }  // namespace v8
+
+namespace cppgc {
+
+class CustomSpaceForTest : public CustomSpace<CustomSpaceForTest> {
+ public:
+  static constexpr size_t kSpaceIndex = 0;
+};
+
+constexpr size_t CustomSpaceForTest::kSpaceIndex;
+
+}  // namespace cppgc
+
+namespace v8 {
+namespace internal {
+
+namespace {
+
+class StatisticsReceiver final : public CustomSpaceStatisticsReceiver {
+ public:
+  static size_t num_calls_;
+
+  StatisticsReceiver(cppgc::CustomSpaceIndex space_index, size_t bytes)
+      : expected_space_index_(space_index), expected_bytes_(bytes) {}
+
+  void AllocatedBytes(cppgc::CustomSpaceIndex space_index, size_t bytes) final {
+    EXPECT_EQ(expected_space_index_.value, space_index.value);
+    EXPECT_EQ(expected_bytes_, bytes);
+    ++num_calls_;
+  }
+
+ private:
+  const cppgc::CustomSpaceIndex expected_space_index_;
+  const size_t expected_bytes_;
+};
+
+size_t StatisticsReceiver::num_calls_ = 0u;
+
+class GCed final : public cppgc::GarbageCollected<GCed> {
+ public:
+  ~GCed() {
+    // Force a finalizer to guarantee sweeping can't finish without the main
+    // thread.
+    USE(data_);
+  }
+  static size_t GetAllocatedSize() {
+    return sizeof(GCed) + sizeof(cppgc::internal::HeapObjectHeader);
+  }
+  void Trace(cppgc::Visitor*) const {}
+
+ private:
+  char data_[KB];
+};
+
+}  // namespace
+}  // namespace internal
+}  // namespace v8
+
+namespace cppgc {
+template <>
+struct SpaceTrait<v8::internal::GCed> {
+  using Space = CustomSpaceForTest;
+};
+
+}  // namespace cppgc
+
+namespace v8 {
+namespace internal {
+
+namespace {
+
+class UnifiedHeapWithCustomSpaceTest : public UnifiedHeapTest {
+ public:
+  static std::vector<std::unique_ptr<cppgc::CustomSpaceBase>>
+  GetCustomSpaces() {
+    std::vector<std::unique_ptr<cppgc::CustomSpaceBase>> custom_spaces;
+    custom_spaces.emplace_back(std::make_unique<cppgc::CustomSpaceForTest>());
+    return custom_spaces;
+  }
+  UnifiedHeapWithCustomSpaceTest() : UnifiedHeapTest(GetCustomSpaces()) {}
+};
+
+}  // namespace
+
+TEST_F(UnifiedHeapWithCustomSpaceTest, CollectCustomSpaceStatisticsAtLastGC) {
+  StatisticsReceiver::num_calls_ = 0;
+  // Initial state.
+  cpp_heap().CollectCustomSpaceStatisticsAtLastGC(
+      {cppgc::CustomSpaceForTest::kSpaceIndex},
+      std::make_unique<StatisticsReceiver>(
+          cppgc::CustomSpaceForTest::kSpaceIndex, 0u));
+  EXPECT_EQ(1u, StatisticsReceiver::num_calls_);
+  // State unpdated only after GC.
+  cppgc::Persistent<GCed> live_obj =
+      cppgc::MakeGarbageCollected<GCed>(allocation_handle());
+  cppgc::MakeGarbageCollected<GCed>(allocation_handle());
+  cpp_heap().CollectCustomSpaceStatisticsAtLastGC(
+      {cppgc::CustomSpaceForTest::kSpaceIndex},
+      std::make_unique<StatisticsReceiver>(
+          cppgc::CustomSpaceForTest::kSpaceIndex, 0u));
+  EXPECT_EQ(2u, StatisticsReceiver::num_calls_);
+  // Check state after GC.
+  CollectGarbageWithoutEmbedderStack(cppgc::Heap::SweepingType::kAtomic);
+  cpp_heap().CollectCustomSpaceStatisticsAtLastGC(
+      {cppgc::CustomSpaceForTest::kSpaceIndex},
+      std::make_unique<StatisticsReceiver>(
+          cppgc::CustomSpaceForTest::kSpaceIndex, GCed::GetAllocatedSize()));
+  EXPECT_EQ(3u, StatisticsReceiver::num_calls_);
+  // State callback delayed during sweeping.
+  cppgc::Persistent<GCed> another_live_obj =
+      cppgc::MakeGarbageCollected<GCed>(allocation_handle());
+  while (v8::platform::PumpMessageLoop(
+      V8::GetCurrentPlatform(), v8_isolate(),
+      v8::platform::MessageLoopBehavior::kDoNotWait)) {
+    // Empty the message loop to avoid finalizing garbage collections through
+    // unrelated tasks.
+  }
+  CollectGarbageWithoutEmbedderStack(
+      cppgc::Heap::SweepingType::kIncrementalAndConcurrent);
+  DCHECK(cpp_heap().sweeper().IsSweepingInProgress());
+  cpp_heap().CollectCustomSpaceStatisticsAtLastGC(
+      {cppgc::CustomSpaceForTest::kSpaceIndex},
+      std::make_unique<StatisticsReceiver>(
+          cppgc::CustomSpaceForTest::kSpaceIndex,
+          2 * GCed::GetAllocatedSize()));
+  while (v8::platform::PumpMessageLoop(
+      V8::GetCurrentPlatform(), v8_isolate(),
+      v8::platform::MessageLoopBehavior::kWaitForWork)) {
+    if (3 < StatisticsReceiver::num_calls_) {
+      EXPECT_FALSE(cpp_heap().sweeper().IsSweepingInProgress());
+      break;
+    }
+  }
+  EXPECT_EQ(4u, StatisticsReceiver::num_calls_);
+}
+
+}  // namespace internal
+}  // namespace v8

test/unittests/heap/unified-heap-utils.cc

@@ -15,9 +15,14 @@ namespace v8 {
 namespace internal {
 
 UnifiedHeapTest::UnifiedHeapTest()
+    : UnifiedHeapTest(std::vector<std::unique_ptr<cppgc::CustomSpaceBase>>()) {}
+
+UnifiedHeapTest::UnifiedHeapTest(
+    std::vector<std::unique_ptr<cppgc::CustomSpaceBase>> custom_spaces)
     : cpp_heap_(v8::CppHeap::Create(
           V8::GetCurrentPlatform(),
-          CppHeapCreateParams{{}, WrapperHelper::DefaultWrapperDescriptor()})) {
+          CppHeapCreateParams{std::move(custom_spaces),
+                              WrapperHelper::DefaultWrapperDescriptor()})) {
   isolate()->heap()->AttachCppHeap(cpp_heap_.get());
 }
 

test/unittests/heap/unified-heap-utils.h

@@ -21,6 +21,8 @@ class CppHeap;
 class UnifiedHeapTest : public TestWithHeapInternals {
  public:
   UnifiedHeapTest();
+  explicit UnifiedHeapTest(
+      std::vector<std::unique_ptr<cppgc::CustomSpaceBase>>);
   ~UnifiedHeapTest() override = default;
 
   void CollectGarbageWithEmbedderStack(cppgc::Heap::SweepingType sweeping_type =