// Copyright 2025 The Chromium Authors // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #include "cc/metrics/scroll_jank_v4_histogram_emitter.h" #include #include #include "base/memory/weak_ptr.h" #include "base/test/metrics/histogram_tester.h" #include "cc/metrics/scroll_jank_os_reporter.h" #include "cc/metrics/scroll_jank_v4_result.h" #include "testing/gmock/include/gmock/gmock.h" #include "testing/gtest/include/gtest/gtest.h" namespace cc { namespace { constexpr JankReasonArray MakeMissedVsyncCounts( std::initializer_list> values) { JankReasonArray result = {}; // Default initialize to 0 for (const auto& [reason, missed_vsyncs] : values) { result[static_cast(reason)] += missed_vsyncs; } return result; } constexpr JankReasonArray kNonJankyFrame = {}; constexpr bool kDamaging = true; constexpr bool kNonDamaging = false; void ExpectNoFixedWindowHistograms( const base::HistogramTester& histogram_tester) { histogram_tester.ExpectTotalCount( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow", 0); histogram_tester.ExpectTotalCount( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDueToDeceleratingInputFrameDelivery", 0); histogram_tester.ExpectTotalCount( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDuringFastScroll", 0); histogram_tester.ExpectTotalCount( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncAtStartOfFling", 0); histogram_tester.ExpectTotalCount( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDuringFling", 0); histogram_tester.ExpectTotalCount( "Event.ScrollJank.MissedVsyncsSum4.FixedWindow", 0); histogram_tester.ExpectTotalCount( "Event.ScrollJank.MissedVsyncsMax4.FixedWindow", 0); } void ExpectNoPerScrollHistograms( const base::HistogramTester& histogram_tester) { histogram_tester.ExpectTotalCount( "Event.ScrollJank.DelayedFramesPercentage4.PerScroll", 0); } void ExpectNoHistograms(const base::HistogramTester& histogram_tester) { ExpectNoFixedWindowHistograms(histogram_tester); ExpectNoPerScrollHistograms(histogram_tester); } } // namespace class ScrollJankV4HistogramEmitterTest : public testing::Test { protected: std::unique_ptr histogram_emitter_ = std::make_unique(); }; TEST_F(ScrollJankV4HistogramEmitterTest, EmitsFixedWindowHistogramsEvery64Frames) { // First window: Histograms should be emitted after the 64th frame. { base::HistogramTester histogram_tester; // Frames 1-10: Non-janky. for (int i = 1; i <= 10; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } // Frame 11: Janky for ALL reasons. histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({ {JankReason::kMissedVsyncDueToDeceleratingInputFrameDelivery, 1}, {JankReason::kMissedVsyncDuringFastScroll, 2}, {JankReason::kMissedVsyncAtStartOfFling, 3}, {JankReason::kMissedVsyncDuringFling, 4}, }), kDamaging); // Frames 12-20: Non-janky. for (int i = 12; i <= 20; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } // Frames 21-22: Janky due to violating the running consistency rule. for (int i = 21; i <= 22; i++) { histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({ {JankReason::kMissedVsyncDueToDeceleratingInputFrameDelivery, 1}, }), kDamaging); } // Frames 23-30: Non-janky. for (int i = 23; i <= 30; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } // Frame 31-33: Janky due to violating the fast scroll continuity rule. for (int i = 31; i <= 33; i++) { histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({ {JankReason::kMissedVsyncDuringFastScroll, 1}, }), kDamaging); } // Frames 34-40: Non-janky. for (int i = 34; i <= 40; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } // Frame 41-44: Janky due to violating the fling continuity rule at the // transition from a fast scroll. for (int i = 41; i <= 44; i++) { histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({ {JankReason::kMissedVsyncAtStartOfFling, 1}, }), kDamaging); } // Frames 45-50: Non-janky. for (int i = 45; i <= 50; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } // Frames 51-55: Janky due to violating the fling continuity rule in the // middle of a fling. for (int i = 51; i <= 55; i++) { histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({ {JankReason::kMissedVsyncDuringFling, 1}, }), kDamaging); } // Frames 56-63: Non-janky. for (int i = 56; i <= 63; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } ExpectNoHistograms(histogram_tester); // Frame 64: Non-janky. histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow", 15 * 100 / 64 /* Frames 11, 21-22, 31-33, 41-44 & 51-55 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDueToDeceleratingInputFrameDelivery", 3 * 100 / 64 /* Frames 11 & 21-22 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDuringFastScroll", 4 * 100 / 64 /* Frames 11 & 31-33 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncAtStartOfFling", 5 * 100 / 64 /* Frames 11 & 41-44 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDuringFling", 6 * 100 / 64 /* Frames 11 & 51-55 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.MissedVsyncsSum4.FixedWindow", 4 + 1 + 2 + 3 + 4 + 5 /* Frames 11, 21-22, 31-33, 41-44 & 51-55 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.MissedVsyncsMax4.FixedWindow", 4 /* Frame 11 */, 1); ExpectNoPerScrollHistograms(histogram_tester); } // Second window: Histograms should be emitted after the next 64th frame. { base::HistogramTester histogram_tester; for (int i = 1; i <= 63; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } ExpectNoHistograms(histogram_tester); // Frame 64. histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow", 0, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDueToDeceleratingInputFrameDelivery", 0, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDuringFastScroll", 0, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncAtStartOfFling", 0, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDuringFling", 0, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.MissedVsyncsSum4.FixedWindow", 0, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.MissedVsyncsMax4.FixedWindow", 0, 1); ExpectNoPerScrollHistograms(histogram_tester); } } TEST_F(ScrollJankV4HistogramEmitterTest, EmitsPerScrollHistogramsAtEndOfScroll) { // Scroll 1: Histograms SHOULD be emitted after it ends. { base::HistogramTester histogram_tester; histogram_emitter_->OnScrollStarted(); // First scroll. // 1 non-janky frame. histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); // 5 janky frames. histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({ {JankReason::kMissedVsyncDueToDeceleratingInputFrameDelivery, 1}, {JankReason::kMissedVsyncDuringFastScroll, 2}, {JankReason::kMissedVsyncAtStartOfFling, 3}, {JankReason::kMissedVsyncDuringFling, 4}, }), kDamaging); histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({ {JankReason::kMissedVsyncDueToDeceleratingInputFrameDelivery, 1}, }), kDamaging); histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({ {JankReason::kMissedVsyncDuringFastScroll, 1}, }), kDamaging); histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({ {JankReason::kMissedVsyncAtStartOfFling, 1}, }), kDamaging); histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({ {JankReason::kMissedVsyncDuringFling, 1}, }), kDamaging); // 1 non-janky frame. histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); ExpectNoHistograms(histogram_tester); histogram_emitter_->OnScrollEnded(); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.PerScroll", 5 * 100 / 7, 1); ExpectNoFixedWindowHistograms(histogram_tester); } // Scroll 2: NO histograms for the second scroll should be emitted before it // ends. { base::HistogramTester histogram_tester; // Robustness test: Under normal circumstances, the histogram emitter should // have received a scroll begin event for the second scroll, but it didn't // for some unexpected reason. The histogram emitter should be able to // handle this situation, using the fact that the first scroll has just // ended. for (int i = 1; i <= 10; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } ExpectNoHistograms(histogram_tester); } // UMA histograms for the second scroll SHOULD be emitted when the third // scroll begins. { base::HistogramTester histogram_tester; // Robustness test: Under normal circumstances, the histogram emitter should // have received a scroll end event for the second scroll, but it didn't for // some unexpected reason. The histogram emitter should be able to handle // this situation, by falling back to emitting UMA histograms for the second // scroll when the third scroll begins. histogram_emitter_->OnScrollStarted(); // Third scroll. histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.PerScroll", 0, 1); ExpectNoFixedWindowHistograms(histogram_tester); } // NO histograms should be emitted for the third scroll, even after it ends, // because it was empty. NO histograms should also be emitted for the fourth // scroll before the histogram emitter is destroyed. { base::HistogramTester histogram_tester; histogram_emitter_->OnScrollEnded(); // Third scroll. histogram_emitter_->OnScrollStarted(); // Fourth scroll. // 1 non-janky frame. histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); // 1 janky frame. histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({ {JankReason::kMissedVsyncDuringFastScroll, 4}, {JankReason::kMissedVsyncDuringFling, 2}, }), kDamaging); // 1 non-janky frame. histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); // Fourth scroll. ExpectNoHistograms(histogram_tester); } // UMA histograms for the fourth scroll SHOULD be emitted when the histogram // emitter is destroyed. { base::HistogramTester histogram_tester; delete histogram_emitter_.release(); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.PerScroll", 1 * 100 / 3, 1); ExpectNoFixedWindowHistograms(histogram_tester); } } /* A combined scenario which tests that the histogram emitter emits both fixed window and per-scroll UMA histograms. This test also verifies that the emission of fixed window and per-scroll histograms is independent (e.g. a scroll ending in the middle of a fixed window shouldn't affect the fixed window calculation and vice versa). Presented frame: :1 32:33 64:65 96:97 128: Fixed windows: |<-------window 1------>|<-------window 2------>| Scrolls: ||<------scroll 2------->|| Delayed frames: : 1 : 2 : 4 : 8 : */ TEST_F(ScrollJankV4HistogramEmitterTest, EmitsBothFixedWindowAndPerScrollHistogramsIndependently) { // Scroll 1, frames 1-32: Histograms SHOULD be emitted after the scroll ends. { base::HistogramTester histogram_tester; histogram_emitter_->OnScrollStarted(); // Frames 1-10: Non-janky. for (int i = 1; i <= 10; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } // Frame 11: Janky for ALL reasons. histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({ {JankReason::kMissedVsyncDueToDeceleratingInputFrameDelivery, 1}, {JankReason::kMissedVsyncDuringFastScroll, 2}, {JankReason::kMissedVsyncAtStartOfFling, 3}, {JankReason::kMissedVsyncDuringFling, 4}, }), kDamaging); // Frames 12-32: Non-janky. for (int i = 12; i <= 32; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } ExpectNoHistograms(histogram_tester); histogram_emitter_->OnScrollEnded(); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.PerScroll", 1 * 100 / 32 /* Frame 11 */, 1); ExpectNoFixedWindowHistograms(histogram_tester); } // Start of scroll 2, frames 33-64: Fixed window histograms should be emitted // after frame 64. { base::HistogramTester histogram_tester; histogram_emitter_->OnScrollStarted(); // Frames 33-50: Non-janky. for (int i = 33; i <= 50; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } // Frames 51-52: Janky due to violating the running consistency rule. for (int i = 51; i <= 52; i++) { histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({ {JankReason::kMissedVsyncDueToDeceleratingInputFrameDelivery, 1}, }), kDamaging); } // Frames 53-63: Non-janky. for (int i = 53; i <= 63; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } ExpectNoHistograms(histogram_tester); // Frame 64: Non-janky. histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow", 3 * 100 / 64 /* Frames 11 & 51-52 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDueToDeceleratingInputFrameDelivery", 3 * 100 / 64 /* Frames 11 & 51-52 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDuringFastScroll", 1 * 100 / 64 /* Frame 11 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncAtStartOfFling", 1 * 100 / 64 /* Frame 11 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDuringFling", 1 * 100 / 64 /* Frame 11 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.MissedVsyncsSum4.FixedWindow", 4 + 2 /* Frames 11 & 51-52 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.MissedVsyncsMax4.FixedWindow", 4 /* Frame 11 */, 1); ExpectNoPerScrollHistograms(histogram_tester); } // Frames 65-96, end of scroll 2: Per-scroll histograms SHOULD be emitted // after the scroll ends. { base::HistogramTester histogram_tester; // Frames 65-80: Non-janky. for (int i = 65; i <= 80; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } // Frames 81-84: Janky due to violating the fast scroll continuity rule. for (int i = 81; i <= 84; i++) { histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({ {JankReason::kMissedVsyncDuringFastScroll, 17}, }), kDamaging); } // Frames 85-96: Non-janky. for (int i = 85; i <= 96; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } ExpectNoHistograms(histogram_tester); histogram_emitter_->OnScrollEnded(); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.PerScroll", 6 * 100 / 64 /* Frame 51-52 & 81-84 */, 1); ExpectNoFixedWindowHistograms(histogram_tester); } // Start of scroll 3, frames 97-128: Fixed window histograms SHOULD be emitted // after frame 128. { base::HistogramTester histogram_tester; histogram_emitter_->OnScrollStarted(); // Frames 97-110: Non-janky. for (int i = 97; i <= 110; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } // Frame 111-118: Janky due to violating the fling continuity rule at the // transition from a fast scroll. for (int i = 111; i <= 118; i++) { histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({ {JankReason::kMissedVsyncAtStartOfFling, 19}, }), kDamaging); } // Frames 119-127: Non-janky. for (int i = 119; i <= 127; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } ExpectNoHistograms(histogram_tester); // Frame 128: Non-janky. histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow", 12 * 100 / 64 /* Frames 81-84 & 111-118 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDueToDeceleratingInputFrameDelivery", 0, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDuringFastScroll", 4 * 100 / 64 /* Frames 81-84 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncAtStartOfFling", 8 * 100 / 64 /* Frames 111-118 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDuringFling", 0, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.MissedVsyncsSum4.FixedWindow", 4 * 17 + 8 * 19 /* Frames 81-84 & 111-118 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.MissedVsyncsMax4.FixedWindow", 19 /* Frames 111-118 */, 1); ExpectNoPerScrollHistograms(histogram_tester); } // End of scroll 3: Per-scroll histograms SHOULD be emitted. { base::HistogramTester histogram_tester; histogram_emitter_->OnScrollEnded(); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.PerScroll", 8 * 100 / 32 /* Frames 111-118 */, 1); ExpectNoFixedWindowHistograms(histogram_tester); } } TEST_F(ScrollJankV4HistogramEmitterTest, IgnoresEmptyScrolls) { // 10 empty scrolls: NO histograms should be emitted. { base::HistogramTester histogram_tester; for (int s = 1; s <= 10; s++) { histogram_emitter_->OnScrollStarted(); histogram_emitter_->OnScrollEnded(); } ExpectNoHistograms(histogram_tester); } // Start of scroll 11, frames 1-64: Fixed window histograms SHOULD be emitted // after frame 64. { base::HistogramTester histogram_tester; histogram_emitter_->OnScrollStarted(); for (int i = 1; i <= 63; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } ExpectNoHistograms(histogram_tester); // Frame 64. histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({ {JankReason::kMissedVsyncDuringFastScroll, 5}, }), kDamaging); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow", 1 * 100 / 64 /* Frame 64 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDueToDeceleratingInputFrameDelivery", 0, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDuringFastScroll", 1 * 100 / 64 /* Frame 64 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncAtStartOfFling", 0, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDuringFling", 0, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.MissedVsyncsSum4.FixedWindow", 5 /* Frame 64 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.MissedVsyncsMax4.FixedWindow", 5 /* Frame 64 */, 1); ExpectNoPerScrollHistograms(histogram_tester); } // End of scroll 11: Per-scroll histograms SHOULD be emitted. { base::HistogramTester histogram_tester; histogram_emitter_->OnScrollEnded(); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.PerScroll", 1 * 100 / 64 /* Frame 64 */, 1); ExpectNoFixedWindowHistograms(histogram_tester); } } TEST_F(ScrollJankV4HistogramEmitterTest, CountsSingletonScrolls) { // 10 singleton scrolls: Per-scroll histograms SHOULD be emitted for each // scroll. for (int s = 1; s <= 10; s++) { base::HistogramTester histogram_tester; histogram_emitter_->OnScrollStarted(); histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); histogram_emitter_->OnScrollEnded(); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.PerScroll", 0, 1); ExpectNoFixedWindowHistograms(histogram_tester); } // Start of scroll 11, frames 11-64: Fixed window histograms SHOULD be emitted // after frame 64. { base::HistogramTester histogram_tester; histogram_emitter_->OnScrollStarted(); for (int i = 11; i <= 63; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } ExpectNoHistograms(histogram_tester); // Frame 64. histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({ {JankReason::kMissedVsyncDuringFastScroll, 5}, }), kDamaging); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow", 1 * 100 / 64 /* Frame 64 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDueToDeceleratingInputFrameDelivery", 0, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDuringFastScroll", 1 * 100 / 64 /* Frame 64 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncAtStartOfFling", 0, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDuringFling", 0, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.MissedVsyncsSum4.FixedWindow", 5 /* Frame 64 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.MissedVsyncsMax4.FixedWindow", 5 /* Frame 64 */, 1); ExpectNoPerScrollHistograms(histogram_tester); } // End of scroll 11: Per-scroll histograms SHOULD be emitted. { base::HistogramTester histogram_tester; histogram_emitter_->OnScrollEnded(); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.PerScroll", 1 * 100 / 54 /* Frame 64 */, 1); ExpectNoFixedWindowHistograms(histogram_tester); } } // Regression test for https://crbug.com/475797611. TEST_F(ScrollJankV4HistogramEmitterTest, ShouldNotCrashWhenAllFramesAreJanky) { base::HistogramTester histogram_tester; for (int i = 0; i < 64; i++) { histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts( {{JankReason::kMissedVsyncDueToDeceleratingInputFrameDelivery, 1}}), kDamaging); } histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow", 100, 1); } TEST_F(ScrollJankV4HistogramEmitterTest, CountsNonDamagingFrames) { // Scroll 1 with frames 1-27 (all damaging): Per-scroll histograms SHOULD be // emitted after the scroll ends. { base::HistogramTester histogram_tester; histogram_emitter_->OnScrollStarted(); for (int i = 1; i <= 13; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } // Frames 14 & 15: Janky damaging frames. histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts( {{JankReason::kMissedVsyncDueToDeceleratingInputFrameDelivery, 1}}), kDamaging); histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts( {{JankReason::kMissedVsyncDueToDeceleratingInputFrameDelivery, 2}}), kDamaging); for (int i = 16; i <= 27; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } ExpectNoHistograms(histogram_tester); histogram_emitter_->OnScrollEnded(); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.PerScroll", 2 * 100 / 27 /* Frames 14 & 15 */, 1); ExpectNoFixedWindowHistograms(histogram_tester); } // Start of scroll 2 with frames 28-147 (all non-damaging): NO histograms // should be emitted. { base::HistogramTester histogram_tester; histogram_emitter_->OnScrollStarted(); for (int i = 28; i <= 88; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kNonDamaging); } // Frame 89: Janky non-damaging frame. histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({{JankReason::kMissedVsyncDuringFastScroll, 4}}), kNonDamaging); for (int i = 90; i <= 140; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kNonDamaging); } // Frame 141: Janky non-damaging frame. histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({{JankReason::kMissedVsyncDuringFastScroll, 8}}), kNonDamaging); for (int i = 142; i <= 147; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kNonDamaging); } // `histogram_emitter_` doesn't yet know whether scroll 2 contains any // damaging frames, so even though it has already encountered 147 frames, it // hasn't emitted any fixed window UMA histograms. ExpectNoHistograms(histogram_tester); } // Frame 148 (damaging): Fixed window histograms for frames 1-64 and 65-128 // SHOULD be emitted. { base::HistogramTester histogram_tester; histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts( {{JankReason::kMissedVsyncDueToDeceleratingInputFrameDelivery, 16}}), kDamaging); EXPECT_THAT( histogram_tester.GetAllSamples( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow"), base::BucketsAre(base::Bucket(2 * 100 / 64, 1) /* Frames 14 & 15 */, base::Bucket(1 * 100 / 64, 1) /* Frame 89 */ )); EXPECT_THAT( histogram_tester.GetAllSamples( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDueToDeceleratingInputFrameDelivery"), base::BucketsAre(base::Bucket(2 * 100 / 64, 1) /* Frames 14 & 15 */, base::Bucket(0, 1))); EXPECT_THAT(histogram_tester.GetAllSamples( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDuringFastScroll"), base::BucketsAre(base::Bucket(0, 1), base::Bucket(1 * 100 / 64, 1) /* Frame 89 */ )); EXPECT_THAT(histogram_tester.GetAllSamples( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncAtStartOfFling"), base::BucketsAre(base::Bucket(0, 2))); EXPECT_THAT(histogram_tester.GetAllSamples( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDuringFling"), base::BucketsAre(base::Bucket(0, 2))); EXPECT_THAT(histogram_tester.GetAllSamples( "Event.ScrollJank.MissedVsyncsSum4.FixedWindow"), base::BucketsAre(base::Bucket(1 + 2, 1) /* Frames 14 & 15 */, base::Bucket(4, 1) /* Frame 89 */)); EXPECT_THAT(histogram_tester.GetAllSamples( "Event.ScrollJank.MissedVsyncsMax4.FixedWindow"), base::BucketsAre(base::Bucket(2, 1) /* Frame 15 */, base::Bucket(4, 1) /* Frame 89 */)); ExpectNoPerScrollHistograms(histogram_tester); } // Frames 149-192 (non-damaging): Fixed window histograms for frames 129-192 // SHOULD be emitted after frame 192. { base::HistogramTester histogram_tester; for (int i = 149; i <= 170; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kNonDamaging); } // Frames 171-173: Janky non-damaging frame. histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({{JankReason::kMissedVsyncDuringFastScroll, 32}}), kNonDamaging); histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({{JankReason::kMissedVsyncDuringFastScroll, 64}}), kNonDamaging); histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts( {{JankReason::kMissedVsyncDuringFastScroll, 128}}), kNonDamaging); for (int i = 174; i <= 191; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kNonDamaging); } ExpectNoHistograms(histogram_tester); // Frame 192: Non-janky non-damaging frame. histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow", 5 * 100 / 64 /* Frames 141, 148 & 171-173 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDueToDeceleratingInputFrameDelivery", 1 * 100 / 64 /* Frame 148 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDuringFastScroll", 4 * 100 / 64 /* Frames 141 & 171-173 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncAtStartOfFling", 0, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDuringFling", 0, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.MissedVsyncsSum4.FixedWindow", 8 + 16 + 32 + 64 + 128 /* Frames 141, 148 & 171-173 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.MissedVsyncsMax4.FixedWindow", 128 /* Frame 173 */, 1); ExpectNoPerScrollHistograms(histogram_tester); } // Frames 193-227 (non-damaging), end of scroll 2: Per-scroll histograms // SHOULD be emitted after the scroll ends. { base::HistogramTester histogram_tester; for (int i = 193; i <= 227; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kNonDamaging); } ExpectNoHistograms(histogram_tester); histogram_emitter_->OnScrollEnded(); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.PerScroll", 6 * 100 / 200 /* Frames 89, 141, 148 & 171-173 */, 1); ExpectNoFixedWindowHistograms(histogram_tester); } // Start of scroll 3 with frames 228-256 (all damaging): Fixed window // histograms for frames 193-256 SHOULD be emitted after frame 256. { base::HistogramTester histogram_tester; histogram_emitter_->OnScrollStarted(); for (int i = 228; i <= 240; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } // Frames 241-242: Janky damaging frames. histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({{JankReason::kMissedVsyncAtStartOfFling, 256}}), kDamaging); histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({{JankReason::kMissedVsyncDuringFling, 512}}), kDamaging); for (int i = 243; i <= 255; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } ExpectNoHistograms(histogram_tester); // Frame 256: Non-janky damaging frame. histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow", 2 * 100 / 64 /* Frames 241 & 242 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDueToDeceleratingInputFrameDelivery", 0, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDuringFastScroll", 0, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncAtStartOfFling", 1 * 100 / 64 /* Frame 241 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDuringFling", 1 * 100 / 64 /* Frame 242 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.MissedVsyncsSum4.FixedWindow", 256 + 512 /* Frames 241 & 242 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.MissedVsyncsMax4.FixedWindow", 512 /* Frame 242 */, 1); ExpectNoPerScrollHistograms(histogram_tester); } // End of scroll 3: Per-scroll histograms SHOULD be emitted. { base::HistogramTester histogram_tester; histogram_emitter_->OnScrollEnded(); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.PerScroll", 2 * 100 / 29 /* Frames 241 & 242 */, 1); ExpectNoFixedWindowHistograms(histogram_tester); } } TEST_F(ScrollJankV4HistogramEmitterTest, IgnoresCompletelyNonDamagingScrolls) { // Scroll 1 with 32 damaging frames: Per-scroll histograms SHOULD be emitted // after the scroll ends. { base::HistogramTester histogram_tester; histogram_emitter_->OnScrollStarted(); for (int i = 1; i <= 15; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } // Frame 16: Janky damaging frame histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts( {{JankReason::kMissedVsyncDueToDeceleratingInputFrameDelivery, 2}}), kDamaging); for (int i = 17; i <= 32; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } ExpectNoHistograms(histogram_tester); histogram_emitter_->OnScrollEnded(); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.PerScroll", 1 * 100 / 32 /* Frame 16 */, 1); ExpectNoFixedWindowHistograms(histogram_tester); } // COMPLETELY NON-DAMAGING scroll 2: NO histograms should be emitted. { base::HistogramTester histogram_tester; histogram_emitter_->OnScrollStarted(); for (int non_damaging = 1; non_damaging <= 50; non_damaging++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kNonDamaging); } // Note: This jank will be lost because it's within a completely // non-damaging scroll. histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({{JankReason::kMissedVsyncDuringFastScroll, 3}}), kNonDamaging); for (int non_damaging = 52; non_damaging <= 100; non_damaging++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kNonDamaging); } histogram_emitter_->OnScrollEnded(); ExpectNoHistograms(histogram_tester); } // Start of scroll 3 with 32 damaging frames: Fixed window histograms SHOULD // be emitted after frame 64. { base::HistogramTester histogram_tester; histogram_emitter_->OnScrollStarted(); for (int i = 33; i <= 47; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } // Frame 48: Janky damaging frame histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({{JankReason::kMissedVsyncDuringFling, 4}}), kDamaging); for (int i = 49; i <= 63; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); } ExpectNoHistograms(histogram_tester); // Frame 64: Non-janky damaging frame. histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow", 2 * 100 / 64 /* Frames 16 & 48 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDueToDeceleratingInputFrameDelivery", 1 * 100 / 64 /* Frame 16 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDuringFastScroll", 0, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncAtStartOfFling", 0, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow." "MissedVsyncDuringFling", 1 * 100 / 64 /* Frame 48 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.MissedVsyncsSum4.FixedWindow", 2 + 4 /* Frames 16 & 48 */, 1); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.MissedVsyncsMax4.FixedWindow", 4 /* Frame 48 */, 1); ExpectNoPerScrollHistograms(histogram_tester); } // End of scroll 3: Per-scroll histograms SHOULD be emitted. { base::HistogramTester histogram_tester; histogram_emitter_->OnScrollEnded(); histogram_tester.ExpectUniqueSample( "Event.ScrollJank.DelayedFramesPercentage4.PerScroll", 1 * 100 / 32 /* Frame 48 */, 1); ExpectNoFixedWindowHistograms(histogram_tester); } } TEST_F(ScrollJankV4HistogramEmitterTest, LimitsNumberOfPendingFixedWindows) { base::HistogramTester histogram_tester; histogram_emitter_->OnScrollStarted(); // If the emitter didn't limit the number of pending fixed windows, there // would be 100 pending windows. for (int i = 1; i <= 6400; i++) { histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kNonDamaging); } ExpectNoHistograms(histogram_tester); histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); // However, the emitter limits the number of pending fixed windows to 20. EXPECT_THAT(histogram_tester.GetAllSamples( "Event.ScrollJank.DelayedFramesPercentage4.FixedWindow"), base::BucketsAre(base::Bucket(0, 20))); } class MockScrollJankOsReporter : public ScrollJankOsReporter { public: MOCK_METHOD(void, ReportScrollJankStats, (uint32_t total_frames, uint32_t janky_frames), (override)); base::WeakPtr GetWeakPtr() { return weak_factory_.GetWeakPtr(); } private: base::WeakPtrFactory weak_factory_{this}; }; TEST_F(ScrollJankV4HistogramEmitterTest, ReportsScrollJankStatsToOs) { testing::StrictMock os_reporter; histogram_emitter_->SetOsReporter(os_reporter.GetWeakPtr()); histogram_emitter_->OnScrollStarted(); histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({{JankReason::kMissedVsyncDuringFling, 2}}), kDamaging); EXPECT_CALL(os_reporter, ReportScrollJankStats(2, 1)).Times(1); histogram_emitter_->OnScrollEnded(); } TEST_F(ScrollJankV4HistogramEmitterTest, DeletingOsReporterDoesNotCauseCrash) { { testing::StrictMock os_reporter; histogram_emitter_->SetOsReporter(os_reporter.GetWeakPtr()); } histogram_emitter_->OnScrollStarted(); histogram_emitter_->OnFrameWithScrollUpdates(kNonJankyFrame, kDamaging); histogram_emitter_->OnFrameWithScrollUpdates( MakeMissedVsyncCounts({{JankReason::kMissedVsyncDuringFling, 2}}), kDamaging); histogram_emitter_->OnScrollEnded(); } } // namespace cc