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

QoS policy ● Timer -- periodical notification/callback ● Time/Time Source -- different type of clocks ● Actionlib w/ RethinkRobotics* -- preemptable task management ● Message Gen (idl) -- dynamic

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

Tuple heap_multiplier = 4 itertasks(limit=None)[source] rebuild_taskheap(timetuple=clocks.timetuple'>)[source] task_count = 0 task_event(type_, fields)[source] Deprecated, use event() syncing state with neighbor workers. At startup, or upon consumer restart, this will: Sync logical clocks. Sync revoked tasks. compatible_transport(app)[source] compatible_transports = {'amqp', 'redis'} syncing state with neighbor workers. At startup, or upon consumer restart, this will: Sync logical clocks. Sync revoked tasks. compatible_transport(app)[source] compatible_transports = {'amqp', 'redis'}

anymore, and must make sure to remove it. Events are now ordered using logical time Keeping physical clocks in perfect sync is impossible, so using time-stamps to order events in a distributed system isn’t difference between the senders time and the internal time is greater than 15 seconds, suggesting that the clocks are out of sync. Monotonic clock support. A monotonic clock is now used for timeouts and scheduling heap_multiplier = 4 State.itertasks(limit=None)[source] State.rebuild_taskheap(timetuple=clocks.timetuple'>) [source] State.task_count = 0 State.task_event(type_, fields)[source] Deprecated

anymore, and must make sure to remove it. Events are now ordered using logical time Keeping physical clocks in perfect sync is impossible, so using time-stamps to order events in a distributed system isn’t difference between the senders time and the internal time is greater than 15 seconds, suggesting that the clocks are out of sync. Monotonic clock support. A monotonic clock is now used for timeouts and scheduling heap_multiplier = 4 State.itertasks(limit=None)[source] State.rebuild_taskheap(timetuple=clocks.timetuple'>) [source] State.task_count = 0 State.task_event(type_, fields)[source] Deprecated

Tuple heap_multiplier = 4 itertasks(limit=None)[source] rebuild_taskheap(timetuple=clocks.timetuple'>)[source] task_count = 0 task_event(type_, fields)[source] Deprecated, use event() syncing state with neighbor workers. At startup, or upon consumer restart, this will: Sync logical clocks. Sync revoked tasks. compatible_transport(app)[source] compatible_transports = {'amqp', 'redis'} syncing state with neighbor workers. At startup, or upon consumer restart, this will: Sync logical clocks. Sync revoked tasks. compatible_transport(app)[source] compatible_transports = {'amqp', 'redis'}