Add a unit test for timers

Source/platform/TimerTest.cpp

Index: Source/platform/TimerTest.cpp
diff --git a/Source/platform/TimerTest.cpp b/Source/platform/TimerTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..4773cd6ddc1ea71ef48c980781dbd57b29b89f3a
--- /dev/null
+++ b/Source/platform/TimerTest.cpp
@@ -0,0 +1,684 @@
+// Copyright 2015 The Chromium 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 "config.h"
+#include "platform/Timer.h"
+
+#include "public/platform/Platform.h"
+#include "public/platform/WebScheduler.h"
+#include "public/platform/WebThread.h"
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+#include <queue>
+
+using testing::ElementsAre;
+
+namespace blink {
+namespace {
+double gCurrentTimeSecs = 0.0;
+
+double currentTime()
+{
+    return gCurrentTimeSecs;
+}
+
+class MockWebScheduler : public WebScheduler {
+public:
+    explicit MockWebScheduler() { }
+    ~MockWebScheduler() override { }
+
+    bool shouldYieldForHighPriorityWork() override
+    {
+        return false;
+    }
+
+    bool canExceedIdleDeadlineIfRequired() override
+    {
+        return false;
+    }
+
+    void postIdleTask(const WebTraceLocation&, WebThread::IdleTask*) override
+    {
+    }
+
+    void postNonNestableIdleTask(const WebTraceLocation&, WebThread::IdleTask*) override
+    {
+    }
+
+    void postIdleTaskAfterWakeup(const WebTraceLocation&, WebThread::IdleTask*) override
+    {
+    }
+
+    void postLoadingTask(const WebTraceLocation&, WebThread::Task*) override
+    {
+    }
+
+    void postTimerTask(const WebTraceLocation&, WebThread::Task* task, long long delayMs) override
+    {
+    }
+};
+
+class FakeWebThread : public WebThread {
+public:
+    explicit FakeWebThread(WebScheduler* webScheduler) : m_webScheduler(webScheduler) { }
+    ~FakeWebThread() override { }
+
+    // WebThread implementation:
+    void postTask(const WebTraceLocation&, Task*)
+    {
+        ASSERT_NOT_REACHED();
+    }
+
+    virtual void postDelayedTask(const WebTraceLocation&, Task*, long long)
+    {
+        ASSERT_NOT_REACHED();
+    }
+
+    virtual bool isCurrentThread() const
+    {
+        ASSERT_NOT_REACHED();
+        return true;
+    }
+
+    virtual PlatformThreadId threadId() const
+    {
+        ASSERT_NOT_REACHED();
+        return 0;
+    }
+
+    WebScheduler* scheduler() const override
+    {
+        return m_webScheduler;
+    }
+
+    virtual void enterRunLoop()
+    {
+        ASSERT_NOT_REACHED();
+    }
+
+    virtual void exitRunLoop()
+    {
+        ASSERT_NOT_REACHED();
+    }
+
+private:
+    WebScheduler* m_webScheduler;
+};
+
+class TimerTestPlatform : public Platform {
+public:
+    explicit TimerTestPlatform(WebThread* webThread)
+        : m_webThread(webThread)
+        , m_timerInterval(-1) { }
+    ~TimerTestPlatform() override { }
+
+    WebThread* currentThread() override
+    {
+        return m_webThread;
+    }
+
+    void cryptographicallyRandomValues(unsigned char*, size_t) override
+    {
+        ASSERT_NOT_REACHED();
+    }
+
+    const unsigned char* getTraceCategoryEnabledFlag(const char* categoryName) override
+    {
+        static const unsigned char enabled[] = {0};
+        return enabled;
+    }
+
+    void setSharedTimerFiredFunction(SharedTimerFunction timerFunction) override
+    {
+        s_timerFunction = timerFunction;
+    }
+
+    void setSharedTimerFireInterval(double interval) override
+    {
+        m_timerInterval = interval;
+    }
+
+    virtual void stopSharedTimer() override
+    {
+        m_timerInterval = -1;
+    }
+
+    void runUntilIdle()
+    {
+        while (hasOneTimerTask()) {
+            gCurrentTimeSecs += m_timerInterval;
+            s_timerFunction();
+        }
+    }
+
+    void runUntilIdleOrDeadlinePassed(double deadline)
+    {
+        while (hasOneTimerTask()) {
+            double newTime = gCurrentTimeSecs + m_timerInterval;
+            if (newTime >= deadline) {
+                gCurrentTimeSecs = deadline;
+                break;
+            }
+            gCurrentTimeSecs = newTime;
+            s_timerFunction();
+        }
+    }
+
+    bool hasOneTimerTask() const
+    {
+        return s_timerFunction && m_timerInterval >= 0;
+    }
+
+    long nextTimerTaskDelayMillis() const
+    {
+        ASSERT(hasOneTimerTask());
+        return static_cast<long>(m_timerInterval * 1000);
+    }
+
+private:
+    WebThread* m_webThread;
+    double m_timerInterval;
+
+    // This needs to be static because the callback is registered only once by
+    // PlatformThreadData.
+    static SharedTimerFunction s_timerFunction;
+};
+
+Platform::SharedTimerFunction TimerTestPlatform::s_timerFunction;
+
+class TimerTest : public testing::Test {
+public:
+    void SetUp() override
+    {
+        m_mockWebScheduler = adoptPtr(new MockWebScheduler());
+        m_fakeWebThread = adoptPtr(new FakeWebThread(m_mockWebScheduler.get()));
+        m_platform = adoptPtr(new TimerTestPlatform(m_fakeWebThread.get()));
+        m_oldPlatform = Platform::current();
+        Platform::initialize(m_platform.get());
+        WTF::setMonotonicallyIncreasingTimeFunction(currentTime);
+
+        m_runTimes.clear();
+        gCurrentTimeSecs = 10.0;
+        m_startTime = gCurrentTimeSecs;
+    }
+
+    void TearDown() override
+    {
+        Platform::initialize(m_oldPlatform);
+    }
+
+    void countingTask(Timer<TimerTest>*)
+    {
+        m_runTimes.push_back(monotonicallyIncreasingTime());
+    }
+
+    void advanceTimeBy(double timeSecs)
+    {
+        gCurrentTimeSecs += timeSecs;
+    }
+
+    void runUntilIdle()
+    {
+        m_platform->runUntilIdle();
+    }
+
+    void runUntilIdleOrDeadlinePassed(double deadline)
+    {
+        m_platform->runUntilIdleOrDeadlinePassed(deadline);
+    }
+
+    bool hasOneTimerTask() const
+    {
+        return m_platform->hasOneTimerTask();
+    }
+
+    long nextTimerTaskDelayMillis() const
+    {
+        return m_platform->nextTimerTaskDelayMillis();
+    }
+
+protected:
+    double m_startTime;
+    std::vector<double> m_runTimes;
+
+private:
+    OwnPtr<MockWebScheduler> m_mockWebScheduler;
+    OwnPtr<FakeWebThread> m_fakeWebThread;
+    OwnPtr<TimerTestPlatform> m_platform;
+    Platform* m_oldPlatform;
+};
+
+TEST_F(TimerTest, StartOneShot_Zero)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startOneShot(0, FROM_HERE);
+
+    ASSERT(hasOneTimerTask());
+    EXPECT_EQ(0ll, nextTimerTaskDelayMillis());
+
+    runUntilIdle();
+    EXPECT_THAT(m_runTimes, ElementsAre(m_startTime));
+}
+
+TEST_F(TimerTest, StartOneShot_ZeroAndCancel)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startOneShot(0, FROM_HERE);
+
+    ASSERT(hasOneTimerTask());
+    EXPECT_EQ(0ll, nextTimerTaskDelayMillis());
+
+    timer.stop();
+
+    runUntilIdle();
+    EXPECT_TRUE(m_runTimes.empty());
+}
+
+TEST_F(TimerTest, StartOneShot_ZeroAndCancelThenRepost)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startOneShot(0, FROM_HERE);
+
+    ASSERT(hasOneTimerTask());
+    EXPECT_EQ(0ll, nextTimerTaskDelayMillis());
+
+    timer.stop();
+
+    runUntilIdle();
+    EXPECT_TRUE(m_runTimes.empty());
+
+    timer.startOneShot(0, FROM_HERE);
+
+    ASSERT(hasOneTimerTask());
+    EXPECT_EQ(0ll, nextTimerTaskDelayMillis());
+
+    runUntilIdle();
+    EXPECT_THAT(m_runTimes, ElementsAre(m_startTime));
+}
+
+TEST_F(TimerTest, StartOneShot_Zero_RepostingAfterRunning)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startOneShot(0, FROM_HERE);
+
+    ASSERT(hasOneTimerTask());
+    EXPECT_EQ(0ll, nextTimerTaskDelayMillis());
+
+    runUntilIdle();
+    EXPECT_THAT(m_runTimes, ElementsAre(m_startTime));
+
+    timer.startOneShot(0, FROM_HERE);
+
+    ASSERT(hasOneTimerTask());
+    EXPECT_EQ(0ll, nextTimerTaskDelayMillis());
+
+    runUntilIdle();
+    EXPECT_THAT(m_runTimes, ElementsAre(m_startTime, m_startTime));
+}
+
+TEST_F(TimerTest, StartOneShot_NonZero)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startOneShot(10.0, FROM_HERE);
+
+    ASSERT(hasOneTimerTask());
+    EXPECT_EQ(10000ll, nextTimerTaskDelayMillis());
+
+    runUntilIdle();
+    EXPECT_THAT(m_runTimes, ElementsAre(m_startTime + 10.0));
+}
+
+TEST_F(TimerTest, StartOneShot_NonZeroAndCancel)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startOneShot(10, FROM_HERE);
+
+    ASSERT(hasOneTimerTask());
+    EXPECT_EQ(10000ll, nextTimerTaskDelayMillis());
+
+    timer.stop();
+
+    runUntilIdle();
+    EXPECT_TRUE(m_runTimes.empty());
+}
+
+TEST_F(TimerTest, StartOneShot_NonZeroAndCancelThenRepost)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startOneShot(10, FROM_HERE);
+
+    ASSERT(hasOneTimerTask());
+    EXPECT_EQ(10000ll, nextTimerTaskDelayMillis());
+
+    timer.stop();
+
+    runUntilIdle();
+    EXPECT_TRUE(m_runTimes.empty());
+
+    double secondPostTime = monotonicallyIncreasingTime();
+    timer.startOneShot(10, FROM_HERE);
+
+    ASSERT(hasOneTimerTask());
+    EXPECT_EQ(10000ll, nextTimerTaskDelayMillis());
+
+    runUntilIdle();
+    EXPECT_THAT(m_runTimes, ElementsAre(secondPostTime + 10.0));
+}
+
+TEST_F(TimerTest, StartOneShot_NonZero_RepostingAfterRunning)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startOneShot(10, FROM_HERE);
+
+    ASSERT(hasOneTimerTask());
+    EXPECT_EQ(10000ll, nextTimerTaskDelayMillis());
+
+    runUntilIdle();
+    EXPECT_THAT(m_runTimes, ElementsAre(m_startTime + 10.0));
+
+    timer.startOneShot(20, FROM_HERE);
+
+    ASSERT(hasOneTimerTask());
+    EXPECT_EQ(20000ll, nextTimerTaskDelayMillis());
+
+    runUntilIdle();
+    EXPECT_THAT(m_runTimes, ElementsAre(m_startTime + 10.0, m_startTime + 30.0));
+}
+
+TEST_F(TimerTest, PostingTimerTwiceWithSameRunTimeDoesNothing)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startOneShot(10, FROM_HERE);
+    timer.startOneShot(10, FROM_HERE);
+
+    ASSERT(hasOneTimerTask());
+    EXPECT_EQ(10000ll, nextTimerTaskDelayMillis());
+
+    runUntilIdle();
+    EXPECT_THAT(m_runTimes, ElementsAre(m_startTime + 10.0));
+}
+
+TEST_F(TimerTest, PostingTimerTwiceWithNewerRunTimeCancelsOriginalTask)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startOneShot(10, FROM_HERE);
+    timer.startOneShot(0, FROM_HERE);
+
+    runUntilIdle();
+    EXPECT_THAT(m_runTimes, ElementsAre(m_startTime + 0.0));
+}
+
+TEST_F(TimerTest, PostingTimerTwiceWithLaterRunTimeCancelsOriginalTask)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startOneShot(0, FROM_HERE);
+    timer.startOneShot(10, FROM_HERE);
+
+    runUntilIdle();
+    EXPECT_THAT(m_runTimes, ElementsAre(m_startTime + 10.0));
+}
+
+TEST_F(TimerTest, StartRepeatingTask)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startRepeating(1.0, FROM_HERE);
+
+    ASSERT(hasOneTimerTask());
+    EXPECT_EQ(1000ll, nextTimerTaskDelayMillis());
+
+    runUntilIdleOrDeadlinePassed(m_startTime + 5.5);
+    EXPECT_THAT(m_runTimes, ElementsAre(
+        m_startTime + 1.0, m_startTime + 2.0, m_startTime + 3.0, m_startTime + 4.0, m_startTime + 5.0));
+}
+
+TEST_F(TimerTest, StartRepeatingTask_ThenCancel)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startRepeating(1.0, FROM_HERE);
+
+    ASSERT(hasOneTimerTask());
+    EXPECT_EQ(1000ll, nextTimerTaskDelayMillis());
+
+    runUntilIdleOrDeadlinePassed(m_startTime + 2.5);
+    EXPECT_THAT(m_runTimes, ElementsAre(m_startTime + 1.0, m_startTime + 2.0));
+
+    timer.stop();
+    runUntilIdle();
+
+    EXPECT_THAT(m_runTimes, ElementsAre(m_startTime + 1.0, m_startTime + 2.0));
+}
+
+TEST_F(TimerTest, StartRepeatingTask_ThenPostOneShot)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startRepeating(1.0, FROM_HERE);
+
+    ASSERT(hasOneTimerTask());
+    EXPECT_EQ(1000ll, nextTimerTaskDelayMillis());
+
+    runUntilIdleOrDeadlinePassed(m_startTime + 2.5);
+    EXPECT_THAT(m_runTimes, ElementsAre(m_startTime + 1.0, m_startTime + 2.0));
+
+    timer.startOneShot(0, FROM_HERE);
+    runUntilIdle();
+
+    EXPECT_THAT(m_runTimes, ElementsAre(m_startTime + 1.0, m_startTime + 2.0, m_startTime + 2.5));
+}
+
+TEST_F(TimerTest, IsActive_NeverPosted)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+
+    EXPECT_FALSE(timer.isActive());
+}
+
+TEST_F(TimerTest, IsActive_AfterPosting_OneShotZero)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startOneShot(0, FROM_HERE);
+
+    EXPECT_TRUE(timer.isActive());
+}
+
+TEST_F(TimerTest, IsActive_AfterPosting_OneShotNonZero)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startOneShot(10, FROM_HERE);
+
+    EXPECT_TRUE(timer.isActive());
+}
+
+TEST_F(TimerTest, IsActive_AfterPosting_Repeating)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startRepeating(1.0, FROM_HERE);
+
+    EXPECT_TRUE(timer.isActive());
+}
+
+TEST_F(TimerTest, IsActive_AfterRunning_OneShotZero)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startOneShot(0, FROM_HERE);
+
+    runUntilIdle();
+    EXPECT_FALSE(timer.isActive());
+}
+
+TEST_F(TimerTest, IsActive_AfterRunning_OneShotNonZero)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startOneShot(10, FROM_HERE);
+
+    runUntilIdle();
+    EXPECT_FALSE(timer.isActive());
+}
+
+TEST_F(TimerTest, IsActive_AfterRunning_Repeating)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startRepeating(1.0, FROM_HERE);
+
+    runUntilIdleOrDeadlinePassed(m_startTime + 10);
+    EXPECT_TRUE(timer.isActive()); // It should run until cancelled.
+}
+
+TEST_F(TimerTest, NextFireInterval_OneShotZero)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startOneShot(0, FROM_HERE);
+
+    EXPECT_FLOAT_EQ(0.0, timer.nextFireInterval());
+}
+
+TEST_F(TimerTest, NextFireInterval_OneShotNonZero)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startOneShot(10, FROM_HERE);
+
+    EXPECT_FLOAT_EQ(10.0, timer.nextFireInterval());
+}
+
+TEST_F(TimerTest, NextFireInterval_OneShotNonZero_AfterAFewSeconds)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startOneShot(10, FROM_HERE);
+
+    advanceTimeBy(2.0);
+    EXPECT_FLOAT_EQ(8.0, timer.nextFireInterval());
+}
+
+TEST_F(TimerTest, NextFireInterval_Repeating)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startRepeating(20, FROM_HERE);
+
+    EXPECT_FLOAT_EQ(20.0, timer.nextFireInterval());
+}
+
+TEST_F(TimerTest, RepeatInterval_NeverStarted)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+
+    EXPECT_FLOAT_EQ(0.0, timer.repeatInterval());
+}
+
+TEST_F(TimerTest, RepeatInterval_OneShotZero)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startOneShot(0, FROM_HERE);
+
+    EXPECT_FLOAT_EQ(0.0, timer.repeatInterval());
+}
+
+TEST_F(TimerTest, RepeatInterval_OneShotNonZero)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startOneShot(10, FROM_HERE);
+
+    EXPECT_FLOAT_EQ(0.0, timer.repeatInterval());
+}
+
+TEST_F(TimerTest, RepeatInterval_Repeating)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startRepeating(20, FROM_HERE);
+
+    EXPECT_FLOAT_EQ(20.0, timer.repeatInterval());
+}
+
+TEST_F(TimerTest, AugmentRepeatInterval)
+{
+    Timer<TimerTest> timer(this, &TimerTest::countingTask);
+    timer.startRepeating(10, FROM_HERE);
+    EXPECT_FLOAT_EQ(10.0, timer.repeatInterval());
+    EXPECT_FLOAT_EQ(10.0, timer.nextFireInterval());
+
+    advanceTimeBy(2.0);
+    timer.augmentRepeatInterval(10);
+
+    EXPECT_FLOAT_EQ(20.0, timer.repeatInterval());
+    EXPECT_FLOAT_EQ(18.0, timer.nextFireInterval());
+
+    runUntilIdleOrDeadlinePassed(m_startTime + 50.0);
+    EXPECT_THAT(m_runTimes, ElementsAre(m_startTime + 20.0, m_startTime + 40.0));
+}
+
+class MockTimerWithAlignment : public TimerBase {
+public:
+    MockTimerWithAlignment() : m_lastFireTime(0.0), m_alignedFireTime(0.0) { }
+
+    virtual void fired() override
+    {
+    }
+
+    double alignedFireTime(double fireTime) const override
+    {
+        m_lastFireTime = fireTime;
+        return m_alignedFireTime;
+    }
+
+    void setAlignedFireTime(double alignedFireTime)
+    {
+        m_alignedFireTime = alignedFireTime;
+    }
+
+    double lastFireTime() const
+    {
+        return m_lastFireTime;
+    }
+
+private:
+    mutable double m_lastFireTime;
+    double m_alignedFireTime;
+};
+
+TEST_F(TimerTest, TimerAlignment_OneShotZero)
+{
+    MockTimerWithAlignment timer;
+    timer.setAlignedFireTime(m_startTime + 1.0);
+
+    timer.start(0.0, 0.0, FROM_HERE);
+
+    // The nextFireInterval gets overrriden.
+    EXPECT_FLOAT_EQ(1.0, timer.nextFireInterval());
+    EXPECT_FLOAT_EQ(0.0, timer.nextUnalignedFireInterval());
+    EXPECT_FLOAT_EQ(m_startTime, timer.lastFireTime());
+}
+
+TEST_F(TimerTest, TimerAlignment_OneShotNonZero)
+{
+    MockTimerWithAlignment timer;
+    timer.setAlignedFireTime(m_startTime + 1.0);
+
+    timer.start(0.5, 0.0, FROM_HERE);
+
+    // The nextFireInterval gets overrriden.
+    EXPECT_FLOAT_EQ(1.0, timer.nextFireInterval());
+    EXPECT_FLOAT_EQ(0.5, timer.nextUnalignedFireInterval());
+    EXPECT_FLOAT_EQ(m_startTime + 0.5, timer.lastFireTime());
+}
+
+TEST_F(TimerTest, DidChangeAlignmentInterval)
+{
+    MockTimerWithAlignment timer;
+    timer.setAlignedFireTime(m_startTime + 1.0);
+
+    timer.start(0.0, 0.0, FROM_HERE);
+
+    EXPECT_FLOAT_EQ(1.0, timer.nextFireInterval());
+    EXPECT_FLOAT_EQ(0.0, timer.nextUnalignedFireInterval());
+    EXPECT_FLOAT_EQ(m_startTime, timer.lastFireTime());
+
+    timer.setAlignedFireTime(m_startTime);
+    timer.didChangeAlignmentInterval();
+
+    EXPECT_FLOAT_EQ(0.0, timer.nextFireInterval());
+    EXPECT_FLOAT_EQ(0.0, timer.nextUnalignedFireInterval());
+    EXPECT_FLOAT_EQ(m_startTime, timer.lastFireTime());
+}
+
+
+} // namespace
+} // namespace blink