// Copyright 2020 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "src/heap/cppgc/metric-recorder.h"

#include "src/heap/cppgc/stats-collector.h"
#include "test/unittests/heap/cppgc/tests.h"

namespace cppgc {
namespace internal {

namespace {
class MetricRecorderImpl final : public MetricRecorder {
 public:
  void AddMainThreadEvent(const CppGCFullCycle& event) final {
    CppGCFullCycle_event = event;
    CppGCFullCycle_callcount++;
  }
  void AddMainThreadEvent(const CppGCMainThreadIncrementalMark& event) final {
    CppGCMainThreadIncrementalMark_event = event;
    CppGCMainThreadIncrementalMark_callcount++;
  }
  void AddMainThreadEvent(const CppGCMainThreadIncrementalSweep& event) final {
    CppGCMainThreadIncrementalSweep_event = event;
    CppGCMainThreadIncrementalSweep_callcount++;
  }

  static size_t CppGCFullCycle_callcount;
  static CppGCFullCycle CppGCFullCycle_event;
  static size_t CppGCMainThreadIncrementalMark_callcount;
  static CppGCMainThreadIncrementalMark CppGCMainThreadIncrementalMark_event;
  static size_t CppGCMainThreadIncrementalSweep_callcount;
  static CppGCMainThreadIncrementalSweep CppGCMainThreadIncrementalSweep_event;
};

// static
size_t MetricRecorderImpl::CppGCFullCycle_callcount = 0u;
MetricRecorderImpl::CppGCFullCycle MetricRecorderImpl::CppGCFullCycle_event;
size_t MetricRecorderImpl::CppGCMainThreadIncrementalMark_callcount = 0u;
MetricRecorderImpl::CppGCMainThreadIncrementalMark
    MetricRecorderImpl::CppGCMainThreadIncrementalMark_event;
size_t MetricRecorderImpl::CppGCMainThreadIncrementalSweep_callcount = 0u;
MetricRecorderImpl::CppGCMainThreadIncrementalSweep
    MetricRecorderImpl::CppGCMainThreadIncrementalSweep_event;

class MetricRecorderTest : public testing::TestWithHeap {
 public:
  MetricRecorderTest() : stats(Heap::From(GetHeap())->stats_collector()) {
    stats->SetMetricRecorderForTesting(std::make_unique<MetricRecorderImpl>());
  }

  void StartGC() {
    stats->NotifyMarkingStarted(
        GarbageCollector::Config::CollectionType::kMajor,
        GarbageCollector::Config::IsForcedGC::kNotForced);
  }
  void EndGC(size_t marked_bytes) {
    stats->NotifyMarkingCompleted(marked_bytes);
    stats->NotifySweepingCompleted();
  }

  StatsCollector* stats;
};
}  // namespace

TEST_F(MetricRecorderTest, IncrementalScopesReportedImmediately) {
  MetricRecorderImpl::CppGCFullCycle_callcount = 0u;
  MetricRecorderImpl::CppGCMainThreadIncrementalMark_callcount = 0u;
  MetricRecorderImpl::CppGCMainThreadIncrementalSweep_callcount = 0u;
  StartGC();
  {
    EXPECT_EQ(0u, MetricRecorderImpl::CppGCMainThreadIncrementalMark_callcount);
    {
      StatsCollector::EnabledScope scope(*Heap::From(GetHeap()),
                                         StatsCollector::kIncrementalMark);
      scope.DecreaseStartTimeForTesting(
          v8::base::TimeDelta::FromMilliseconds(1));
    }
    EXPECT_EQ(1u, MetricRecorderImpl::CppGCMainThreadIncrementalMark_callcount);
    EXPECT_LT(
        0u,
        MetricRecorderImpl::CppGCMainThreadIncrementalMark_event.duration_us);
  }
  {
    EXPECT_EQ(0u,
              MetricRecorderImpl::CppGCMainThreadIncrementalSweep_callcount);
    {
      StatsCollector::EnabledScope scope(*Heap::From(GetHeap()),
                                         StatsCollector::kIncrementalSweep);
      scope.DecreaseStartTimeForTesting(
          v8::base::TimeDelta::FromMilliseconds(1));
    }
    EXPECT_EQ(1u,
              MetricRecorderImpl::CppGCMainThreadIncrementalSweep_callcount);
    EXPECT_LT(
        0u,
        MetricRecorderImpl::CppGCMainThreadIncrementalSweep_event.duration_us);
  }
  EXPECT_EQ(0u, MetricRecorderImpl::CppGCFullCycle_callcount);
  EndGC(0);
}

TEST_F(MetricRecorderTest, NonIncrementlaScopesNotReportedImmediately) {
  MetricRecorderImpl::CppGCFullCycle_callcount = 0u;
  MetricRecorderImpl::CppGCMainThreadIncrementalMark_callcount = 0u;
  MetricRecorderImpl::CppGCMainThreadIncrementalSweep_callcount = 0u;
  StartGC();
  {
    StatsCollector::EnabledScope scope(*Heap::From(GetHeap()),
                                       StatsCollector::kAtomicMark);
  }
  {
    StatsCollector::EnabledScope scope(*Heap::From(GetHeap()),
                                       StatsCollector::kAtomicWeak);
  }
  {
    StatsCollector::EnabledScope scope(*Heap::From(GetHeap()),
                                       StatsCollector::kAtomicCompact);
  }
  {
    StatsCollector::EnabledScope scope(*Heap::From(GetHeap()),
                                       StatsCollector::kAtomicSweep);
  }
  {
    StatsCollector::EnabledConcurrentScope scope(
        *Heap::From(GetHeap()), StatsCollector::kConcurrentMark);
  }
  {
    StatsCollector::EnabledConcurrentScope scope(
        *Heap::From(GetHeap()), StatsCollector::kConcurrentSweep);
  }
  EXPECT_EQ(0u, MetricRecorderImpl::CppGCMainThreadIncrementalMark_callcount);
  EXPECT_EQ(0u, MetricRecorderImpl::CppGCMainThreadIncrementalSweep_callcount);
  EXPECT_EQ(0u, MetricRecorderImpl::CppGCFullCycle_callcount);
  EndGC(0);
}

TEST_F(MetricRecorderTest, CycleEndMetricsReportedOnGcEnd) {
  MetricRecorderImpl::CppGCFullCycle_callcount = 0u;
  MetricRecorderImpl::CppGCMainThreadIncrementalMark_callcount = 0u;
  MetricRecorderImpl::CppGCMainThreadIncrementalSweep_callcount = 0u;
  StartGC();
  EndGC(0);
  EXPECT_EQ(0u, MetricRecorderImpl::CppGCMainThreadIncrementalMark_callcount);
  EXPECT_EQ(0u, MetricRecorderImpl::CppGCMainThreadIncrementalSweep_callcount);
  EXPECT_EQ(1u, MetricRecorderImpl::CppGCFullCycle_callcount);
}

TEST_F(MetricRecorderTest, CycleEndHistogramReportsCorrectValues) {
  StartGC();
  EndGC(1000);
  StartGC();
  {
    StatsCollector::EnabledScope scope(*Heap::From(GetHeap()),
                                       StatsCollector::kIncrementalMark);
    scope.DecreaseStartTimeForTesting(
        v8::base::TimeDelta::FromMilliseconds(10));
  }
  {
    StatsCollector::EnabledScope scope(*Heap::From(GetHeap()),
                                       StatsCollector::kIncrementalSweep);
    scope.DecreaseStartTimeForTesting(
        v8::base::TimeDelta::FromMilliseconds(20));
  }
  {
    StatsCollector::EnabledScope scope(*Heap::From(GetHeap()),
                                       StatsCollector::kAtomicMark);
    scope.DecreaseStartTimeForTesting(
        v8::base::TimeDelta::FromMilliseconds(30));
  }
  {
    StatsCollector::EnabledScope scope(*Heap::From(GetHeap()),
                                       StatsCollector::kAtomicWeak);
    scope.DecreaseStartTimeForTesting(
        v8::base::TimeDelta::FromMilliseconds(50));
  }
  {
    StatsCollector::EnabledScope scope(*Heap::From(GetHeap()),
                                       StatsCollector::kAtomicCompact);
    scope.DecreaseStartTimeForTesting(
        v8::base::TimeDelta::FromMilliseconds(60));
  }
  {
    StatsCollector::EnabledScope scope(*Heap::From(GetHeap()),
                                       StatsCollector::kAtomicSweep);
    scope.DecreaseStartTimeForTesting(
        v8::base::TimeDelta::FromMilliseconds(70));
  }
  {
    StatsCollector::EnabledConcurrentScope scope(
        *Heap::From(GetHeap()), StatsCollector::kConcurrentMark);
    scope.DecreaseStartTimeForTesting(
        v8::base::TimeDelta::FromMilliseconds(80));
  }
  {
    StatsCollector::EnabledConcurrentScope scope(
        *Heap::From(GetHeap()), StatsCollector::kConcurrentSweep);
    scope.DecreaseStartTimeForTesting(
        v8::base::TimeDelta::FromMilliseconds(100));
  }
  EndGC(300);
  // Check durations.
  static constexpr int64_t kDurationComparisonTolerance = 500;
  EXPECT_LT(std::abs(MetricRecorderImpl::CppGCFullCycle_event
                         .main_thread_incremental.mark_duration_us -
                     10000),
            kDurationComparisonTolerance);
  EXPECT_LT(std::abs(MetricRecorderImpl::CppGCFullCycle_event
                         .main_thread_incremental.sweep_duration_us -
                     20000),
            kDurationComparisonTolerance);
  EXPECT_LT(std::abs(MetricRecorderImpl::CppGCFullCycle_event.main_thread_atomic
                         .mark_duration_us -
                     30000),
            kDurationComparisonTolerance);
  EXPECT_LT(std::abs(MetricRecorderImpl::CppGCFullCycle_event.main_thread_atomic
                         .weak_duration_us -
                     50000),
            kDurationComparisonTolerance);
  EXPECT_LT(std::abs(MetricRecorderImpl::CppGCFullCycle_event.main_thread_atomic
                         .compact_duration_us -
                     60000),
            kDurationComparisonTolerance);
  EXPECT_LT(std::abs(MetricRecorderImpl::CppGCFullCycle_event.main_thread_atomic
                         .sweep_duration_us -
                     70000),
            kDurationComparisonTolerance);
  EXPECT_LT(std::abs(MetricRecorderImpl::CppGCFullCycle_event.main_thread
                         .mark_duration_us -
                     40000),
            kDurationComparisonTolerance);
  EXPECT_LT(std::abs(MetricRecorderImpl::CppGCFullCycle_event.main_thread
                         .weak_duration_us -
                     50000),
            kDurationComparisonTolerance);
  EXPECT_LT(std::abs(MetricRecorderImpl::CppGCFullCycle_event.main_thread
                         .compact_duration_us -
                     60000),
            kDurationComparisonTolerance);
  EXPECT_LT(std::abs(MetricRecorderImpl::CppGCFullCycle_event.main_thread
                         .sweep_duration_us -
                     90000),
            kDurationComparisonTolerance);
  EXPECT_LT(
      std::abs(MetricRecorderImpl::CppGCFullCycle_event.total.mark_duration_us -
               120000),
      kDurationComparisonTolerance);
  EXPECT_LT(
      std::abs(MetricRecorderImpl::CppGCFullCycle_event.total.weak_duration_us -
               50000),
      kDurationComparisonTolerance);
  EXPECT_LT(
      std::abs(
          MetricRecorderImpl::CppGCFullCycle_event.total.compact_duration_us -
          60000),
      kDurationComparisonTolerance);
  EXPECT_LT(
      std::abs(
          MetricRecorderImpl::CppGCFullCycle_event.total.sweep_duration_us -
          190000),
      kDurationComparisonTolerance);
  // Check collection rate and efficiency.
  EXPECT_DOUBLE_EQ(
      0.3, MetricRecorderImpl::CppGCFullCycle_event.collection_rate_in_percent);
  static constexpr double kEfficiencyComparisonTolerance = 0.00001;
  EXPECT_LT(
      std::abs(
          MetricRecorderImpl::CppGCFullCycle_event.efficiency_in_bytes_per_us -
          (700.0 / (120000 + 50000 + 60000 + 190000))),
      kEfficiencyComparisonTolerance);
  EXPECT_LT(std::abs(MetricRecorderImpl::CppGCFullCycle_event
                         .main_thread_efficiency_in_bytes_per_us -
                     (700.0 / (40000 + 50000 + 60000 + 90000))),
            kEfficiencyComparisonTolerance);
}

TEST_F(MetricRecorderTest, ObjectSizeMetricsNoAllocations) {
  // Populate previous event.
  StartGC();
  EndGC(1000);
  // Populate current event.
  StartGC();
  EndGC(800);
  EXPECT_EQ(1000u,
            MetricRecorderImpl::CppGCFullCycle_event.objects.before_bytes);
  EXPECT_EQ(800u, MetricRecorderImpl::CppGCFullCycle_event.objects.after_bytes);
  EXPECT_EQ(200u, MetricRecorderImpl::CppGCFullCycle_event.objects.freed_bytes);
  EXPECT_EQ(0u, MetricRecorderImpl::CppGCFullCycle_event.memory.before_bytes);
  EXPECT_EQ(0u, MetricRecorderImpl::CppGCFullCycle_event.memory.after_bytes);
  EXPECT_EQ(0u, MetricRecorderImpl::CppGCFullCycle_event.memory.freed_bytes);
}

TEST_F(MetricRecorderTest, ObjectSizeMetricsWithAllocations) {
  // Populate previous event.
  StartGC();
  EndGC(1000);
  // Populate current event.
  StartGC();
  stats->NotifyAllocation(300);
  stats->NotifyAllocatedMemory(1400);
  stats->NotifyFreedMemory(700);
  stats->NotifyMarkingCompleted(800);
  stats->NotifyAllocation(150);
  stats->NotifyAllocatedMemory(1000);
  stats->NotifyFreedMemory(400);
  stats->NotifySweepingCompleted();
  EXPECT_EQ(1300u,
            MetricRecorderImpl::CppGCFullCycle_event.objects.before_bytes);
  EXPECT_EQ(800, MetricRecorderImpl::CppGCFullCycle_event.objects.after_bytes);
  EXPECT_EQ(500u, MetricRecorderImpl::CppGCFullCycle_event.objects.freed_bytes);
  EXPECT_EQ(700u, MetricRecorderImpl::CppGCFullCycle_event.memory.before_bytes);
  EXPECT_EQ(300u, MetricRecorderImpl::CppGCFullCycle_event.memory.after_bytes);
  EXPECT_EQ(400u, MetricRecorderImpl::CppGCFullCycle_event.memory.freed_bytes);
}

}  // namespace internal
}  // namespace cppgc