SF TimeStats: add unittests for TimeStats

Bug: 119290000
Test: atest libsurfaceflinger_unittest:TimeStatsTest
Change-Id: I27bc835e607090e8a4742b9d384dc579e102f16c
diff --git a/services/surfaceflinger/tests/unittests/TimeStatsTest.cpp b/services/surfaceflinger/tests/unittests/TimeStatsTest.cpp
new file mode 100644
index 0000000..186ed79
--- /dev/null
+++ b/services/surfaceflinger/tests/unittests/TimeStatsTest.cpp
@@ -0,0 +1,513 @@
+/*
+ * Copyright 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#undef LOG_TAG
+#define LOG_TAG "LibSurfaceFlingerUnittests"
+
+#include <gtest/gtest.h>
+
+#include <log/log.h>
+#include <utils/String16.h>
+#include <utils/String8.h>
+#include <utils/Vector.h>
+
+#include <random>
+
+#include "TimeStats/TimeStats.h"
+
+using namespace android::surfaceflinger;
+using namespace google::protobuf;
+
+namespace android {
+namespace {
+
+// clang-format off
+#define FMT_PROTO          true
+#define FMT_STRING         false
+#define LAYER_ID_0         0
+#define LAYER_ID_1         1
+#define LAYER_ID_INVALID   -1
+#define NUM_LAYERS         1
+#define NUM_LAYERS_INVALID "INVALID"
+
+enum InputCommand : int32_t {
+    ENABLE                 = 0,
+    DISABLE                = 1,
+    CLEAR                  = 2,
+    DUMP_ALL               = 3,
+    DUMP_MAXLAYERS_1       = 4,
+    DUMP_MAXLAYERS_INVALID = 5,
+    INPUT_COMMAND_BEGIN    = ENABLE,
+    INPUT_COMMAND_END      = DUMP_MAXLAYERS_INVALID,
+    INPUT_COMMAND_RANGE    = INPUT_COMMAND_END - INPUT_COMMAND_BEGIN + 1,
+};
+
+enum TimeStamp : int32_t {
+    POST                   = 0,
+    ACQUIRE                = 1,
+    ACQUIRE_FENCE          = 2,
+    LATCH                  = 3,
+    DESIRED                = 4,
+    PRESENT                = 5,
+    PRESENT_FENCE          = 6,
+    TIME_STAMP_BEGIN       = POST,
+    TIME_STAMP_END         = PRESENT,
+    TIME_STAMP_RANGE       = TIME_STAMP_END - TIME_STAMP_BEGIN + 1,
+};
+
+static const TimeStamp NORMAL_SEQUENCE[] = {
+        TimeStamp::POST,
+        TimeStamp::ACQUIRE,
+        TimeStamp::LATCH,
+        TimeStamp::DESIRED,
+        TimeStamp::PRESENT,
+};
+
+static const TimeStamp NORMAL_SEQUENCE_2[] = {
+        TimeStamp::POST,
+        TimeStamp::ACQUIRE_FENCE,
+        TimeStamp::LATCH,
+        TimeStamp::DESIRED,
+        TimeStamp::PRESENT_FENCE,
+};
+
+static const TimeStamp UNORDERED_SEQUENCE[] = {
+        TimeStamp::ACQUIRE,
+        TimeStamp::LATCH,
+        TimeStamp::POST,
+        TimeStamp::DESIRED,
+        TimeStamp::PRESENT,
+};
+
+static const TimeStamp INCOMPLETE_SEQUENCE[] = {
+        TimeStamp::POST,
+};
+// clang-format on
+
+class TimeStatsTest : public testing::Test {
+public:
+    TimeStatsTest() {
+        const ::testing::TestInfo* const test_info =
+                ::testing::UnitTest::GetInstance()->current_test_info();
+        ALOGD("**** Setting up for %s.%s\n", test_info->test_case_name(), test_info->name());
+    }
+
+    ~TimeStatsTest() {
+        const ::testing::TestInfo* const test_info =
+                ::testing::UnitTest::GetInstance()->current_test_info();
+        ALOGD("**** Tearing down after %s.%s\n", test_info->test_case_name(), test_info->name());
+    }
+
+    std::string inputCommand(InputCommand cmd, bool useProto);
+
+    void setTimeStamp(TimeStamp type, int32_t id, uint64_t frameNumber, nsecs_t ts);
+
+    int32_t genRandomInt32(int32_t begin, int32_t end);
+
+    template <size_t N>
+    void insertTimeRecord(const TimeStamp (&sequence)[N], int32_t id, uint64_t frameNumber,
+                          nsecs_t ts) {
+        for (size_t i = 0; i < N; i++, ts += 1000000) {
+            setTimeStamp(sequence[i], id, frameNumber, ts);
+        }
+    }
+
+    std::mt19937 mRandomEngine = std::mt19937(std::random_device()());
+    std::unique_ptr<TimeStats> mTimeStats = std::make_unique<TimeStats>();
+};
+
+std::string TimeStatsTest::inputCommand(InputCommand cmd, bool useProto) {
+    size_t index = 0;
+    String8 result;
+    Vector<String16> args;
+
+    switch (cmd) {
+        case InputCommand::ENABLE:
+            args.push_back(String16("-enable"));
+            break;
+        case InputCommand::DISABLE:
+            args.push_back(String16("-disable"));
+            break;
+        case InputCommand::CLEAR:
+            args.push_back(String16("-clear"));
+            break;
+        case InputCommand::DUMP_ALL:
+            args.push_back(String16("-dump"));
+            break;
+        case InputCommand::DUMP_MAXLAYERS_1:
+            args.push_back(String16("-dump"));
+            args.push_back(String16("-maxlayers"));
+            args.push_back(String16(std::to_string(NUM_LAYERS).c_str()));
+            break;
+        case InputCommand::DUMP_MAXLAYERS_INVALID:
+            args.push_back(String16("-dump"));
+            args.push_back(String16("-maxlayers"));
+            args.push_back(String16(NUM_LAYERS_INVALID));
+            break;
+        default:
+            ALOGD("Invalid control command");
+    }
+
+    EXPECT_NO_FATAL_FAILURE(mTimeStats->parseArgs(useProto, args, index, result));
+    return std::string(result.string(), result.size());
+}
+
+static std::string genLayerName(int32_t layerID) {
+    return (layerID < 0 ? "invalid.dummy" : "com.dummy#") + std::to_string(layerID);
+}
+
+void TimeStatsTest::setTimeStamp(TimeStamp type, int32_t id, uint64_t frameNumber, nsecs_t ts) {
+    switch (type) {
+        case TimeStamp::POST:
+            ASSERT_NO_FATAL_FAILURE(mTimeStats->setPostTime(id, frameNumber, genLayerName(id), ts));
+            break;
+        case TimeStamp::ACQUIRE:
+            ASSERT_NO_FATAL_FAILURE(mTimeStats->setAcquireTime(id, frameNumber, ts));
+            break;
+        case TimeStamp::ACQUIRE_FENCE:
+            ASSERT_NO_FATAL_FAILURE(
+                    mTimeStats->setAcquireFence(id, frameNumber, std::make_shared<FenceTime>(ts)));
+            break;
+        case TimeStamp::LATCH:
+            ASSERT_NO_FATAL_FAILURE(mTimeStats->setLatchTime(id, frameNumber, ts));
+            break;
+        case TimeStamp::DESIRED:
+            ASSERT_NO_FATAL_FAILURE(mTimeStats->setDesiredTime(id, frameNumber, ts));
+            break;
+        case TimeStamp::PRESENT:
+            ASSERT_NO_FATAL_FAILURE(mTimeStats->setPresentTime(id, frameNumber, ts));
+            break;
+        case TimeStamp::PRESENT_FENCE:
+            ASSERT_NO_FATAL_FAILURE(
+                    mTimeStats->setPresentFence(id, frameNumber, std::make_shared<FenceTime>(ts)));
+            break;
+        default:
+            ALOGD("Invalid timestamp type");
+    }
+}
+
+int32_t TimeStatsTest::genRandomInt32(int32_t begin, int32_t end) {
+    std::uniform_int_distribution<int32_t> distr(begin, end);
+    return distr(mRandomEngine);
+}
+
+TEST_F(TimeStatsTest, canEnableAndDisableTimeStats) {
+    EXPECT_TRUE(inputCommand(InputCommand::ENABLE, FMT_STRING).empty());
+    ASSERT_TRUE(mTimeStats->isEnabled());
+
+    EXPECT_TRUE(inputCommand(InputCommand::DISABLE, FMT_STRING).empty());
+    ASSERT_FALSE(mTimeStats->isEnabled());
+}
+
+TEST_F(TimeStatsTest, canIncreaseGlobalStats) {
+    constexpr size_t TOTAL_FRAMES = 5;
+    constexpr size_t MISSED_FRAMES = 4;
+    constexpr size_t CLIENT_COMPOSITION_FRAMES = 3;
+
+    EXPECT_TRUE(inputCommand(InputCommand::ENABLE, FMT_STRING).empty());
+
+    for (size_t i = 0; i < TOTAL_FRAMES; i++) {
+        ASSERT_NO_FATAL_FAILURE(mTimeStats->incrementTotalFrames());
+    }
+    for (size_t i = 0; i < MISSED_FRAMES; i++) {
+        ASSERT_NO_FATAL_FAILURE(mTimeStats->incrementMissedFrames());
+    }
+    for (size_t i = 0; i < CLIENT_COMPOSITION_FRAMES; i++) {
+        ASSERT_NO_FATAL_FAILURE(mTimeStats->incrementClientCompositionFrames());
+    }
+
+    SFTimeStatsGlobalProto globalProto;
+    ASSERT_TRUE(globalProto.ParseFromString(inputCommand(InputCommand::DUMP_ALL, FMT_PROTO)));
+
+    ASSERT_TRUE(globalProto.has_total_frames());
+    EXPECT_EQ(TOTAL_FRAMES, globalProto.total_frames());
+    ASSERT_TRUE(globalProto.has_missed_frames());
+    EXPECT_EQ(MISSED_FRAMES, globalProto.missed_frames());
+    ASSERT_TRUE(globalProto.has_client_composition_frames());
+    EXPECT_EQ(CLIENT_COMPOSITION_FRAMES, globalProto.client_composition_frames());
+}
+
+TEST_F(TimeStatsTest, canInsertGlobalPresentToPresent) {
+    EXPECT_TRUE(inputCommand(InputCommand::ENABLE, FMT_STRING).empty());
+
+    ASSERT_NO_FATAL_FAILURE(
+            mTimeStats->setPresentFenceGlobal(std::make_shared<FenceTime>(1000000)));
+    ASSERT_NO_FATAL_FAILURE(
+            mTimeStats->setPresentFenceGlobal(std::make_shared<FenceTime>(2000000)));
+
+    ASSERT_NO_FATAL_FAILURE(mTimeStats->setPowerMode(HWC_POWER_MODE_NORMAL));
+    ASSERT_NO_FATAL_FAILURE(
+            mTimeStats->setPresentFenceGlobal(std::make_shared<FenceTime>(3000000)));
+    ASSERT_NO_FATAL_FAILURE(
+            mTimeStats->setPresentFenceGlobal(std::make_shared<FenceTime>(5000000)));
+
+    ASSERT_NO_FATAL_FAILURE(mTimeStats->setPowerMode(HWC_POWER_MODE_OFF));
+    ASSERT_NO_FATAL_FAILURE(
+            mTimeStats->setPresentFenceGlobal(std::make_shared<FenceTime>(6000000)));
+    ASSERT_NO_FATAL_FAILURE(
+            mTimeStats->setPresentFenceGlobal(std::make_shared<FenceTime>(8000000)));
+
+    SFTimeStatsGlobalProto globalProto;
+    ASSERT_TRUE(globalProto.ParseFromString(inputCommand(InputCommand::DUMP_ALL, FMT_PROTO)));
+
+    ASSERT_EQ(1, globalProto.present_to_present_size());
+    const SFTimeStatsHistogramBucketProto& histogramProto = globalProto.present_to_present().Get(0);
+    EXPECT_EQ(1, histogramProto.frame_count());
+    EXPECT_EQ(2, histogramProto.time_millis());
+}
+
+TEST_F(TimeStatsTest, canInsertOneLayerTimeStats) {
+    EXPECT_TRUE(inputCommand(InputCommand::ENABLE, FMT_STRING).empty());
+
+    insertTimeRecord(NORMAL_SEQUENCE, LAYER_ID_0, 1, 1000000);
+    insertTimeRecord(NORMAL_SEQUENCE_2, LAYER_ID_0, 2, 2000000);
+
+    SFTimeStatsGlobalProto globalProto;
+    ASSERT_TRUE(globalProto.ParseFromString(inputCommand(InputCommand::DUMP_ALL, FMT_PROTO)));
+
+    ASSERT_EQ(1, globalProto.stats_size());
+    const SFTimeStatsLayerProto& layerProto = globalProto.stats().Get(0);
+    ASSERT_TRUE(layerProto.has_layer_name());
+    EXPECT_EQ(genLayerName(LAYER_ID_0), layerProto.layer_name());
+    ASSERT_TRUE(layerProto.has_total_frames());
+    EXPECT_EQ(1, layerProto.total_frames());
+    ASSERT_EQ(6, layerProto.deltas_size());
+    for (const SFTimeStatsDeltaProto& deltaProto : layerProto.deltas()) {
+        ASSERT_EQ(1, deltaProto.histograms_size());
+        const SFTimeStatsHistogramBucketProto& histogramProto = deltaProto.histograms().Get(0);
+        EXPECT_EQ(1, histogramProto.frame_count());
+        if ("post2acquire" == deltaProto.delta_name()) {
+            EXPECT_EQ(1, histogramProto.time_millis());
+        } else if ("post2present" == deltaProto.delta_name()) {
+            EXPECT_EQ(4, histogramProto.time_millis());
+        } else if ("acquire2present" == deltaProto.delta_name()) {
+            EXPECT_EQ(3, histogramProto.time_millis());
+        } else if ("latch2present" == deltaProto.delta_name()) {
+            EXPECT_EQ(2, histogramProto.time_millis());
+        } else if ("desired2present" == deltaProto.delta_name()) {
+            EXPECT_EQ(1, histogramProto.time_millis());
+        } else if ("present2present" == deltaProto.delta_name()) {
+            EXPECT_EQ(1, histogramProto.time_millis());
+        } else {
+            FAIL() << "Unknown delta_name: " << deltaProto.delta_name();
+        }
+    }
+}
+
+TEST_F(TimeStatsTest, canNotInsertInvalidLayerNameTimeStats) {
+    EXPECT_TRUE(inputCommand(InputCommand::ENABLE, FMT_STRING).empty());
+
+    insertTimeRecord(NORMAL_SEQUENCE, LAYER_ID_INVALID, 1, 1000000);
+    insertTimeRecord(NORMAL_SEQUENCE_2, LAYER_ID_INVALID, 2, 2000000);
+
+    SFTimeStatsGlobalProto globalProto;
+    ASSERT_TRUE(globalProto.ParseFromString(inputCommand(InputCommand::DUMP_ALL, FMT_PROTO)));
+
+    ASSERT_EQ(0, globalProto.stats_size());
+}
+
+TEST_F(TimeStatsTest, canInsertMultipleLayersTimeStats) {
+    EXPECT_TRUE(inputCommand(InputCommand::ENABLE, FMT_STRING).empty());
+
+    insertTimeRecord(NORMAL_SEQUENCE, LAYER_ID_0, 1, 1000000);
+    insertTimeRecord(NORMAL_SEQUENCE, LAYER_ID_1, 1, 1000000);
+    insertTimeRecord(NORMAL_SEQUENCE, LAYER_ID_0, 2, 2000000);
+    insertTimeRecord(NORMAL_SEQUENCE, LAYER_ID_1, 2, 2000000);
+
+    SFTimeStatsGlobalProto globalProto;
+    ASSERT_TRUE(globalProto.ParseFromString(inputCommand(InputCommand::DUMP_ALL, FMT_PROTO)));
+
+    EXPECT_EQ(2, globalProto.stats_size());
+}
+
+TEST_F(TimeStatsTest, canInsertUnorderedLayerTimeStats) {
+    EXPECT_TRUE(inputCommand(InputCommand::ENABLE, FMT_STRING).empty());
+
+    insertTimeRecord(NORMAL_SEQUENCE, LAYER_ID_0, 1, 1000000);
+    insertTimeRecord(UNORDERED_SEQUENCE, LAYER_ID_0, 2, 2000000);
+
+    SFTimeStatsGlobalProto globalProto;
+    ASSERT_TRUE(globalProto.ParseFromString(inputCommand(InputCommand::DUMP_ALL, FMT_PROTO)));
+
+    ASSERT_EQ(1, globalProto.stats_size());
+    const SFTimeStatsLayerProto& layerProto = globalProto.stats().Get(0);
+    ASSERT_TRUE(layerProto.has_layer_name());
+    EXPECT_EQ(genLayerName(LAYER_ID_0), layerProto.layer_name());
+    ASSERT_TRUE(layerProto.has_total_frames());
+    EXPECT_EQ(1, layerProto.total_frames());
+    ASSERT_EQ(6, layerProto.deltas_size());
+    for (const SFTimeStatsDeltaProto& deltaProto : layerProto.deltas()) {
+        ASSERT_EQ(1, deltaProto.histograms_size());
+        const SFTimeStatsHistogramBucketProto& histogramProto = deltaProto.histograms().Get(0);
+        EXPECT_EQ(1, histogramProto.frame_count());
+        if ("post2acquire" == deltaProto.delta_name()) {
+            EXPECT_EQ(0, histogramProto.time_millis());
+        } else if ("post2present" == deltaProto.delta_name()) {
+            EXPECT_EQ(2, histogramProto.time_millis());
+        } else if ("acquire2present" == deltaProto.delta_name()) {
+            EXPECT_EQ(2, histogramProto.time_millis());
+        } else if ("latch2present" == deltaProto.delta_name()) {
+            EXPECT_EQ(2, histogramProto.time_millis());
+        } else if ("desired2present" == deltaProto.delta_name()) {
+            EXPECT_EQ(1, histogramProto.time_millis());
+        } else if ("present2present" == deltaProto.delta_name()) {
+            EXPECT_EQ(1, histogramProto.time_millis());
+        } else {
+            FAIL() << "Unknown delta_name: " << deltaProto.delta_name();
+        }
+    }
+}
+
+TEST_F(TimeStatsTest, canRemoveTimeRecord) {
+    EXPECT_TRUE(inputCommand(InputCommand::ENABLE, FMT_STRING).empty());
+
+    insertTimeRecord(NORMAL_SEQUENCE, LAYER_ID_0, 1, 1000000);
+    insertTimeRecord(INCOMPLETE_SEQUENCE, LAYER_ID_0, 2, 2000000);
+    ASSERT_NO_FATAL_FAILURE(mTimeStats->removeTimeRecord(0, 2));
+    insertTimeRecord(NORMAL_SEQUENCE, LAYER_ID_0, 3, 3000000);
+
+    SFTimeStatsGlobalProto globalProto;
+    ASSERT_TRUE(globalProto.ParseFromString(inputCommand(InputCommand::DUMP_ALL, FMT_PROTO)));
+
+    ASSERT_EQ(1, globalProto.stats_size());
+    const SFTimeStatsLayerProto& layerProto = globalProto.stats().Get(0);
+    ASSERT_TRUE(layerProto.has_total_frames());
+    EXPECT_EQ(1, layerProto.total_frames());
+}
+
+TEST_F(TimeStatsTest, canRecoverFromIncompleteTimeRecordError) {
+    EXPECT_TRUE(inputCommand(InputCommand::ENABLE, FMT_STRING).empty());
+
+    uint64_t frameNumber = 1;
+    nsecs_t ts = 1000000;
+    insertTimeRecord(INCOMPLETE_SEQUENCE, LAYER_ID_0, 1, 1000000);
+    for (size_t i = 0; i < TimeStats::MAX_NUM_TIME_RECORDS + 2; i++) {
+        frameNumber++;
+        ts += 1000000;
+        insertTimeRecord(NORMAL_SEQUENCE, LAYER_ID_0, frameNumber, ts);
+    }
+
+    SFTimeStatsGlobalProto globalProto;
+    ASSERT_TRUE(globalProto.ParseFromString(inputCommand(InputCommand::DUMP_ALL, FMT_PROTO)));
+
+    ASSERT_EQ(1, globalProto.stats_size());
+    const SFTimeStatsLayerProto& layerProto = globalProto.stats().Get(0);
+    ASSERT_TRUE(layerProto.has_total_frames());
+    EXPECT_EQ(1, layerProto.total_frames());
+}
+
+TEST_F(TimeStatsTest, layerTimeStatsOnDestroy) {
+    EXPECT_TRUE(inputCommand(InputCommand::ENABLE, FMT_STRING).empty());
+
+    insertTimeRecord(NORMAL_SEQUENCE, LAYER_ID_0, 1, 1000000);
+    insertTimeRecord(NORMAL_SEQUENCE, LAYER_ID_0, 2, 2000000);
+    ASSERT_NO_FATAL_FAILURE(mTimeStats->onDestroy(0));
+    insertTimeRecord(NORMAL_SEQUENCE, LAYER_ID_0, 3, 3000000);
+
+    SFTimeStatsGlobalProto globalProto;
+    ASSERT_TRUE(globalProto.ParseFromString(inputCommand(InputCommand::DUMP_ALL, FMT_PROTO)));
+
+    ASSERT_EQ(1, globalProto.stats_size());
+    const SFTimeStatsLayerProto& layerProto = globalProto.stats().Get(0);
+    ASSERT_TRUE(layerProto.has_total_frames());
+    EXPECT_EQ(1, layerProto.total_frames());
+}
+
+TEST_F(TimeStatsTest, canClearTimeStats) {
+    EXPECT_TRUE(inputCommand(InputCommand::ENABLE, FMT_STRING).empty());
+
+    ASSERT_NO_FATAL_FAILURE(mTimeStats->incrementTotalFrames());
+    ASSERT_NO_FATAL_FAILURE(mTimeStats->incrementMissedFrames());
+    ASSERT_NO_FATAL_FAILURE(mTimeStats->incrementClientCompositionFrames());
+    ASSERT_NO_FATAL_FAILURE(mTimeStats->setPowerMode(HWC_POWER_MODE_NORMAL));
+    ASSERT_NO_FATAL_FAILURE(
+            mTimeStats->setPresentFenceGlobal(std::make_shared<FenceTime>(1000000)));
+    ASSERT_NO_FATAL_FAILURE(
+            mTimeStats->setPresentFenceGlobal(std::make_shared<FenceTime>(2000000)));
+    insertTimeRecord(NORMAL_SEQUENCE, LAYER_ID_0, 1, 1000000);
+    insertTimeRecord(NORMAL_SEQUENCE, LAYER_ID_0, 2, 2000000);
+
+    EXPECT_TRUE(inputCommand(InputCommand::CLEAR, FMT_STRING).empty());
+
+    SFTimeStatsGlobalProto globalProto;
+    ASSERT_TRUE(globalProto.ParseFromString(inputCommand(InputCommand::DUMP_ALL, FMT_PROTO)));
+
+    EXPECT_EQ(0, globalProto.total_frames());
+    EXPECT_EQ(0, globalProto.missed_frames());
+    EXPECT_EQ(0, globalProto.client_composition_frames());
+    EXPECT_EQ(0, globalProto.present_to_present_size());
+    EXPECT_EQ(0, globalProto.stats_size());
+}
+
+TEST_F(TimeStatsTest, canDumpWithMaxLayers) {
+    EXPECT_TRUE(inputCommand(InputCommand::ENABLE, FMT_STRING).empty());
+
+    insertTimeRecord(NORMAL_SEQUENCE, LAYER_ID_0, 1, 1000000);
+    insertTimeRecord(NORMAL_SEQUENCE, LAYER_ID_1, 1, 1000000);
+    insertTimeRecord(NORMAL_SEQUENCE, LAYER_ID_0, 2, 2000000);
+    insertTimeRecord(NORMAL_SEQUENCE, LAYER_ID_1, 2, 2000000);
+    insertTimeRecord(NORMAL_SEQUENCE, LAYER_ID_1, 3, 2000000);
+
+    SFTimeStatsGlobalProto globalProto;
+    ASSERT_TRUE(
+            globalProto.ParseFromString(inputCommand(InputCommand::DUMP_MAXLAYERS_1, FMT_PROTO)));
+
+    ASSERT_EQ(1, globalProto.stats_size());
+    const SFTimeStatsLayerProto& layerProto = globalProto.stats().Get(0);
+    ASSERT_TRUE(layerProto.has_layer_name());
+    EXPECT_EQ(genLayerName(LAYER_ID_1), layerProto.layer_name());
+    ASSERT_TRUE(layerProto.has_total_frames());
+    EXPECT_EQ(2, layerProto.total_frames());
+}
+
+TEST_F(TimeStatsTest, canDumpWithInvalidMaxLayers) {
+    EXPECT_TRUE(inputCommand(InputCommand::ENABLE, FMT_STRING).empty());
+
+    insertTimeRecord(NORMAL_SEQUENCE, LAYER_ID_0, 1, 1000000);
+    insertTimeRecord(NORMAL_SEQUENCE, LAYER_ID_0, 2, 2000000);
+
+    SFTimeStatsGlobalProto globalProto;
+    ASSERT_TRUE(globalProto.ParseFromString(
+            inputCommand(InputCommand::DUMP_MAXLAYERS_INVALID, FMT_PROTO)));
+
+    ASSERT_EQ(0, globalProto.stats_size());
+}
+
+TEST_F(TimeStatsTest, canSurviveMonkey) {
+    EXPECT_TRUE(inputCommand(InputCommand::ENABLE, FMT_STRING).empty());
+
+    for (size_t i = 0; i < 10000000; ++i) {
+        const int32_t layerID = genRandomInt32(-1, 10);
+        const int32_t frameNumber = genRandomInt32(1, 10);
+        switch (genRandomInt32(0, 100)) {
+            case 0:
+                ALOGV("removeTimeRecord");
+                ASSERT_NO_FATAL_FAILURE(mTimeStats->removeTimeRecord(layerID, frameNumber));
+                continue;
+            case 1:
+                ALOGV("onDestroy");
+                ASSERT_NO_FATAL_FAILURE(mTimeStats->onDestroy(layerID));
+                continue;
+        }
+        TimeStamp type = static_cast<TimeStamp>(genRandomInt32(TIME_STAMP_BEGIN, TIME_STAMP_END));
+        const int32_t ts = genRandomInt32(1, 1000000000);
+        ALOGV("type[%d], layerID[%d], frameNumber[%d], ts[%d]", type, layerID, frameNumber, ts);
+        setTimeStamp(type, layerID, frameNumber, ts);
+    }
+}
+
+} // namespace
+} // namespace android