Review Videos! • clocks, clock_cast, leap_seconds (https://youtu.be/WX3OmVu4lAs) • time_zone and time_zone_link (https://youtu.be/MODhhr7m-5s) • system_clock::now(), file_clock, leap second awareness (https://youtu 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 { public: is_steady = false; static time_point now() {} }; static_assert(is_clock_v); For a type T to qualify as a Clock, it must satisfy each of the following conditions: • The following qualified-ids

in :  std::system_clock: wall clock time from system-wide real-time clock  std::steady_clock: guarantees it never goes backwards  std::high_resolution_clock: has shortest possible tick C++20 adds:  utc_clock, tai_clock, gps_clock, and file_clock  Every clock has a now() method21 Clocks – Examples  Example: // Get current time as a time_point. system_clock::time_point tpoint tpoint { system_clock::now() }; // Or: auto tpoint { system_clock::now() }; // Convert to a time_t. time_t tt { system_clock::to_time_t(tpoint) }; // Convert to local time. tm* t { localtime(&tt) }; // Write

uint64_t CPU_CLOCK_HZ = 400'000'000; // API to implement: std::chrono::nanoseconds elapsed_time(uint64_t num_cpu_ticks); 1 2 3 4 8Example: “CPU ticks” time units constexpr uint64_t CPU_CLOCK_HZ = 400'000'000; nds elapsed_time(uint64_t num_cpu_ticks) { using NS_PER_TICK = std::ratio<1'000'000'000, CPU_CLOCK_HZ>; return std::chrono::nanoseconds{ num_cpu_ticks * NS_PER_TICK::num / NS_PER_TICK::den NS_PER_TICK::den }; } 1 2 3 4 5 6 8.1Example: “CPU ticks” time units constexpr uint64_t CPU_CLOCK_HZ = 400'000'000; // API to implement: std::chrono::nanoseconds elapsed_time(uint64_t num_cpu_ticks); 1 2

(int i { startValue }; i < startValue + numberOfValues; ++i) { time_t t { system_clock::to_time_t(system_clock::now()) }; cout << std::ctime(&t); co_yield i; } } int main() { auto gen 1 week into days62 Calendars & Timezones  New clocks (besides system_clock, steady_clock, high_resolution_clock):  utc_clock: represents Coordinated Universal Time (UTC), measures time since 00:00:00 00:00:00 UTC, Thursday, 1 January 1970, including leap seconds  tai_clock: represents International Atomic Time (TAI), measures time since 00:00:00, 1 January 1958, and was offseted 10 seconds ahead of

auto start = Clock::now(); for( size_t i=0; iconcrete(); } auto end = Clock::now(); auto concrete_duration = end-start; start = Clock::now(); for( for( size_t i=0; ivirt(); } end = Clock::now(); auto virt_duration = end-start;There are interesting technical details and surprising conclusions that virtual

above: async def minute_loop2(): while True: nxt = gen.sleep(60) # Start the clock. await do_something() # Run while the clock is ticking. await nxt # Wait for the timer to run out. 6.1.4 Queue example request. • start_time: Time at which the HTTP operation started, based on time.time (not the monotonic clock used by IOLoop.time). May be None if the request timed out while in the queue. • time_info: dictionary implementa- tions. request_time is now more accurate for curl_httpclient because it uses a monotonic clock when available. rethrow() → None If there was an error on the request, raise an HTTPError. Exceptions

in the Game Boy's CPU, typically corresponding to one clock tick of the CPU. Emulators with T-cycle accuracy simulate the exact number of clock ticks for every instruction, providing the highest level in the Game Boy's CPU, typically corresponding to one clock tick of the CPU. Emulators with T-cycle accuracy simulate the exact number of clock ticks for every instruction, providing the highest level

63Modules Timer Clock & Oscillator SysTick UART ADC GPIO Delays (us, ms) PWM Time measurement Communication with PC Analog input LEDs Clock configuration C 64Modules Timer Clock & Oscillator Oscillator SysTick UART ADC GPIO C++ C 65 PWM Time measurement Analog input Clock configuration Delays (us, ms) LEDs Communication with PCEnumerations enum class modes : std::uint32_t { input = 0b00

minute_loop2(): while True: nxt = gen.sleep(60) # Start the clock. await do_something() # Run while the clock is ticking. await nxt # Wait for the timer to run out started, based on time.time [https://docs.python.org/3/library/time.html#time.time] (not the monotonic clock used by IOLoop.time). May be None if the request timed out while in the queue. time_info: dictionary implementations. request_time is now more accurate for curl_httpclient because it uses a monotonic clock when available. rethrow() → None [https://docs.python.org/3/library/constants.html#None] If there

TracyPlot(name, tick); // ... activity ... TracyPlot(name, baseline); baseline up-tick down-tick clock (sustain) plots baseline up-tick down-tick pulse (heartbeat) plots TracyPlot(name, tick); TracyPlot(name palliative workarounds: • Use FrameMarkStart and FrameMarkEnd • Use “matching” TracyMessage’s • Use clock/sustain TracyPlot • Assign unique ZoneColor to each task • My recommendation: use TracyAlloc and (it’s basically a stackable clock/sustain plot!) 87 e.g.: task starts in main thread, moves between worker threads, and gets retired