Process • Implementing in the Open • Organization of Work • Part II: Calendrical Types • Part III: Clocks • Part IV: Leap Seconds • What are leap seconds? • How did we implement them in MSVC? • Part Feature branch (feature/chrono) for rapid development and collaboration • Code Review Videos! • clocks, clock_cast, leap_seconds (https://youtu.be/WX3OmVu4lAs) • time_zone and time_zone_link (https://youtu clients of them! Plus, the types often end up boiling down to constants anyway!18 Part III: Clocks19 What is a clock? #include #include using namespace std::chrono; class MyClock

Compile-Time Rational Numbers  Durations  Clocks  Time Points  Dates  Time Zones 4 Agenda  Compile-Time Rational Numbers  Durations  Clocks  Time Points  Dates  Time Zones5 = ratio<1'000'000'000'000'000'000, 1>;9 Agenda  Compile-Time Rational Numbers  Durations  Clocks  Time Points  Dates  Time Zones10 Durations  Interval between two points in time  Represented // 1.519 Agenda  Compile-Time Rational Numbers  Durations  Clocks  Time Points  Dates  Time Zones20 Clocks  Several clocks available in :  std::system_clock: wall clock time from

wall-clock dependencies in TiDB. Placement Driver, for instance, allocates timestamps based on local wall-clocks, but ensures monotonicity through Raft plus a leader lease. Clock skew between PD nodes can cause strobing the clock up and down ev- ery few milliseconds. We also used libfaketime to simulate some node clocks, both CLOCK_REALTIME and CLOCK_MONOTONIC, running up to 5x faster than oth- ers. PingCAP had written increas- ing. PingCAP and Jepsen believe this could lead to consistency anomalies when monotonic clocks are not well behaved. However, we don’t have experimental ev- idence to confirm this hypothesis.

EtherCAT Video Michael Caisse Using C libraries in your Modern C++ Embedded Project Distributed Clocks Sync0 Sync0/Sync1 DC Jitter System jitter is significantly less than 1us. ciere

the processor starts Fixed locations in Flash memory, �lled with bit- mapped magic values Sets up clocks, memory segments, watchdog timer JTAG debug, code security, and much more 8 . 1/ Config Fuses

weeks w { 1 }; // 1 week days d { w }; // Convert 1 week into days62 Calendars & Timezones  New clocks (besides system_clock, steady_clock, high_resolution_clock):  utc_clock: represents Coordinated

sources you may get a warning or error message about the timing inconsistency. It may also cause clocks to become unreliable with some guest operating systems depending on how they use the TSC. 9.14.2 kernels starting with version 2.6.25. VirtualBox’s implementation currently supports paravirtual- ized clocks and SMP spinlocks. This provider is recommended for Linux guests. • Hyper-V: Presents a Microsoft dows 7 and newer operating systems. VirtualBox’s implementation currently supports par- avirtualized clocks, APIC frequency reporting, guest debugging, guest crash reporting and relaxed timer checks. This

sources you may get a warning or error message about the timing inconsistency. It may also cause clocks to become unreliable with some guest operating systems depending on how they use the TSC. 9.14.2 kernels starting with version 2.6.25. VirtualBox’s implementation currently supports paravirtual- ized clocks and SMP spinlocks. This provider is recommended for Linux guests. • Hyper-V: Presents a Microsoft dows 7 and newer operating systems. VirtualBox’s implementation currently supports par- avirtualized clocks, APIC frequency reporting, guest debugging, guest crash reporting and relaxed timer checks. This

for high schools ©2016 Zenva Pty Ltd all rights reserved Page 128 58 this.groups.clocks.forEachAlive(this.check_collision, this); 59 } 60 }; 61 62 FruitNinja.LevelState.prototype return new FruitNinja.Clock(this.game_state, name, position, {texture: "clock_image", group: "clocks", velocity: velocity}); 16 }; 1 var FruitNinja = FruitNinja || {}; Zenva Academy – Online

sources you may get a warning or error message about the timing inconsistency. It may also cause clocks to become unreliable with some guest operating systems depending on they use the TSC. 9.13.2 Accelerate