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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /widget/tests/gtest/TestTimeConverter.cpp | |
parent | Initial commit. (diff) | |
download | firefox-esr-upstream.tar.xz firefox-esr-upstream.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'widget/tests/gtest/TestTimeConverter.cpp')
-rw-r--r-- | widget/tests/gtest/TestTimeConverter.cpp | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/widget/tests/gtest/TestTimeConverter.cpp b/widget/tests/gtest/TestTimeConverter.cpp new file mode 100644 index 0000000000..22cbc3f9e6 --- /dev/null +++ b/widget/tests/gtest/TestTimeConverter.cpp @@ -0,0 +1,265 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this file, + * You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "gtest/gtest.h" +#include "mozilla/TimeStamp.h" +#include "SystemTimeConverter.h" + +using mozilla::SystemTimeConverter; +using mozilla::TimeDuration; +using mozilla::TimeStamp; + +namespace { + +// This class provides a mock implementation of the CurrentTimeGetter template +// type used in SystemTimeConverter. It can be constructed with a particular +// Time and always returns that Time. +template <typename Time> +class MockCurrentTimeGetter { + public: + MockCurrentTimeGetter() : mTime(0) {} + explicit MockCurrentTimeGetter(Time aTime) : mTime(aTime) {} + + // Methods needed for CurrentTimeGetter compatibility + Time GetCurrentTime() const { return mTime; } + void GetTimeAsyncForPossibleBackwardsSkew(const TimeStamp& aNow) {} + + private: + Time mTime; +}; + +// This is another mock implementation of the CurrentTimeGetter template +// type used in SystemTimeConverter, except this asserts that it will not be +// used. i.e. it should only be used in calls to SystemTimeConverter that we +// know will not invoke it. +template <typename Time> +class UnusedCurrentTimeGetter { + public: + Time GetCurrentTime() const { + EXPECT_TRUE(false); + return 0; + } + + void GetTimeAsyncForPossibleBackwardsSkew(const TimeStamp& aNow) { + EXPECT_TRUE(false); + } +}; + +// This class provides a mock implementation of the TimeStampNowProvider +// template type used in SystemTimeConverter. It also has other things in it +// that allow the test to better control time for testing purposes. +class MockTimeStamp { + public: + // This should generally be called at the start of every test function, as + // it will initialize this class's static fields to sane values. In particular + // it will initialize the baseline TimeStamp against which all other + // TimeStamps are compared. + static void Init() { + sBaseline = TimeStamp::Now(); + sTimeStamp = sBaseline; + } + + // Advance the timestamp returned by `MockTimeStamp::Now()` + static void Advance(double ms) { + sTimeStamp += TimeDuration::FromMilliseconds(ms); + } + + // Returns the baseline TimeStamp, that is used as a fixed reference point + // in time against which other TimeStamps can be compared. This is needed + // because mozilla::TimeStamp itself doesn't provide any conversion to + // human-readable strings, and we need to convert it to a TimeDuration in + // order to get that. This baseline TimeStamp can be used to turn an + // arbitrary TimeStamp into a TimeDuration. + static TimeStamp Baseline() { return sBaseline; } + + // This is the method needed for TimeStampNowProvider compatibility, and + // simulates `TimeStamp::Now()` + static TimeStamp Now() { return sTimeStamp; } + + private: + static TimeStamp sTimeStamp; + static TimeStamp sBaseline; +}; + +TimeStamp MockTimeStamp::sTimeStamp; +TimeStamp MockTimeStamp::sBaseline; + +// Could have platform-specific implementations of this using DWORD, guint32, +// etc behind ifdefs. But this is sufficient for now. +using GTestTime = uint32_t; +using TimeConverter = SystemTimeConverter<GTestTime, MockTimeStamp>; + +} // namespace + +// Checks the expectation that the TimeStamp `ts` is exactly `ms` milliseconds +// after the baseline timestamp. This is a macro so gtest still gives us useful +// line numbers for failures. +#define EXPECT_TS(ts, ms) \ + EXPECT_EQ((ts)-MockTimeStamp::Baseline(), TimeDuration::FromMilliseconds(ms)) + +#define EXPECT_TS_FUZZY(ts, ms) \ + EXPECT_DOUBLE_EQ(((ts)-MockTimeStamp::Baseline()).ToMilliseconds(), ms) + +TEST(TimeConverter, SanityCheck) +{ + MockTimeStamp::Init(); + + MockCurrentTimeGetter timeGetter(10); + UnusedCurrentTimeGetter<GTestTime> unused; + TimeConverter converter; + + // This call sets the reference time and timestamp + TimeStamp ts = converter.GetTimeStampFromSystemTime(10, timeGetter); + EXPECT_TS(ts, 0); + + // Advance "TimeStamp::Now" by 10ms, use the same event time and OS time. + // Since the event time is the same as before, we expect to get back the + // same TimeStamp as before too, despite Now() changing. + MockTimeStamp::Advance(10); + ts = converter.GetTimeStampFromSystemTime(10, unused); + EXPECT_TS(ts, 0); + + // Now let's use an event time 20ms after the old event. This will trigger + // forward skew detection and resync the TimeStamp for the new event to Now(). + ts = converter.GetTimeStampFromSystemTime(30, unused); + EXPECT_TS(ts, 10); +} + +TEST(TimeConverter, Overflow) +{ + // This tests wrapping time around the max value supported in the GTestTime + // type and ensuring it is handled properly. + + MockTimeStamp::Init(); + + const GTestTime max = std::numeric_limits<GTestTime>::max(); + const GTestTime min = std::numeric_limits<GTestTime>::min(); + double fullRange = (double)max - (double)min; + double wrapPeriod = fullRange + 1.0; + + GTestTime almostOverflowed = max - 100; + GTestTime overflowed = max + 100; + MockCurrentTimeGetter timeGetter(almostOverflowed); + UnusedCurrentTimeGetter<GTestTime> unused; + TimeConverter converter; + + // Set reference time to 100ms before the overflow point + TimeStamp ts = + converter.GetTimeStampFromSystemTime(almostOverflowed, timeGetter); + EXPECT_TS(ts, 0); + + // Advance everything by 200ms and verify we get back a TimeStamp 200ms from + // the baseline despite wrapping an overflow. + MockTimeStamp::Advance(200); + ts = converter.GetTimeStampFromSystemTime(overflowed, unused); + EXPECT_TS(ts, 200); + + // Advance by another full wraparound of the time. This loses some precision + // so we have to do the FUZZY match + MockTimeStamp::Advance(wrapPeriod); + ts = converter.GetTimeStampFromSystemTime(overflowed, unused); + EXPECT_TS_FUZZY(ts, 200.0 + wrapPeriod); +} + +TEST(TimeConverter, InvertedOverflow) +{ + // This tests time going from near the min value of GTestTime to the max + // value of GTestTime + + MockTimeStamp::Init(); + + const GTestTime max = std::numeric_limits<GTestTime>::max(); + const GTestTime min = std::numeric_limits<GTestTime>::min(); + double fullRange = (double)max - (double)min; + double wrapPeriod = fullRange + 1.0; + + GTestTime nearRangeMin = min + 100; + GTestTime nearRangeMax = max - 100; + double gap = (double)nearRangeMax - (double)nearRangeMin; + + MockCurrentTimeGetter timeGetter(nearRangeMin); + UnusedCurrentTimeGetter<GTestTime> unused; + TimeConverter converter; + + // Set reference time to value near min numeric limit + TimeStamp ts = converter.GetTimeStampFromSystemTime(nearRangeMin, timeGetter); + EXPECT_TS(ts, 0); + + // Advance to value near max numeric limit + MockTimeStamp::Advance(gap); + ts = converter.GetTimeStampFromSystemTime(nearRangeMax, unused); + EXPECT_TS(ts, gap); + + // Advance by another full wraparound of the time. This loses some precision + // so we have to do the FUZZY match + MockTimeStamp::Advance(wrapPeriod); + ts = converter.GetTimeStampFromSystemTime(nearRangeMax, unused); + EXPECT_TS_FUZZY(ts, gap + wrapPeriod); +} + +TEST(TimeConverter, HalfRangeBoundary) +{ + MockTimeStamp::Init(); + + GTestTime max = std::numeric_limits<GTestTime>::max(); + GTestTime min = std::numeric_limits<GTestTime>::min(); + double fullRange = (double)max - (double)min; + double wrapPeriod = fullRange + 1.0; + GTestTime halfRange = (GTestTime)(fullRange / 2.0); + GTestTime halfWrapPeriod = (GTestTime)(wrapPeriod / 2.0); + + TimeConverter converter; + + GTestTime firstEvent = 10; + MockCurrentTimeGetter timeGetter(firstEvent); + UnusedCurrentTimeGetter<GTestTime> unused; + + // Set reference time + TimeStamp ts = converter.GetTimeStampFromSystemTime(firstEvent, timeGetter); + EXPECT_TS(ts, 0); + + // Advance event time by just under the half-period, to trigger about as big + // a forwards skew as we possibly can. + GTestTime secondEvent = firstEvent + (halfWrapPeriod - 1); + ts = converter.GetTimeStampFromSystemTime(secondEvent, unused); + EXPECT_TS(ts, 0); + + // The above forwards skew will have reset the reference timestamp. Now + // advance Now time by just under the half-range, to trigger about as big + // a backwards skew as we possibly can. + MockTimeStamp::Advance(halfRange - 1); + ts = converter.GetTimeStampFromSystemTime(secondEvent, unused); + EXPECT_TS(ts, 0); +} + +TEST(TimeConverter, FractionalMillisBug1626734) +{ + MockTimeStamp::Init(); + + TimeConverter converter; + + GTestTime eventTime = 10; + MockCurrentTimeGetter timeGetter(eventTime); + UnusedCurrentTimeGetter<GTestTime> unused; + + TimeStamp ts = converter.GetTimeStampFromSystemTime(eventTime, timeGetter); + EXPECT_TS(ts, 0); + + MockTimeStamp::Advance(0.2); + ts = converter.GetTimeStampFromSystemTime(eventTime, unused); + EXPECT_TS(ts, 0); + + MockTimeStamp::Advance(0.9); + TimeStamp ts2 = converter.GetTimeStampFromSystemTime(eventTime, unused); + EXPECT_TS(ts2, 0); + + // Since ts2 came from a "future" call relative to ts, we expect ts2 to not + // be "before" ts. (i.e. time shouldn't go backwards, even by fractional + // milliseconds). This assertion is technically already implied by the + // EXPECT_TS checks above, but fixing this assertion is the end result that + // we wanted in bug 1626734 so it feels appropriate to recheck it explicitly. + EXPECT_TRUE(ts <= ts2); +} |