clock – Page 3 – Tarik Billa

How do I get monotonic time durations in python?

April 3, 2023 by Tarik

That function is simple enough that you can use ctypes to access it: #!/usr/bin/env python __all__ = [“monotonic_time”] import ctypes, os CLOCK_MONOTONIC_RAW = 4 # see <linux/time.h> class timespec(ctypes.Structure): _fields_ = [ (‘tv_sec’, ctypes.c_long), (‘tv_nsec’, ctypes.c_long) ] librt = ctypes.CDLL(‘librt.so.1’, use_errno=True) clock_gettime = librt.clock_gettime clock_gettime.argtypes = [ctypes.c_int, ctypes.POINTER(timespec)] def monotonic_time(): t = timespec() if clock_gettime(CLOCK_MONOTONIC_RAW … Read more

Emulator’s clock doesn’t match the host system clock

April 1, 2023 by Tarik

I had the same problem and got it resolved by just restarting the emulator using emulator power button.

How to create a JQuery Clock / Timer

March 21, 2023 by Tarik

You’re looking for the setInterval function, which runs a function every x milliseconds. For example: var start = new Date; setInterval(function() { $(‘.Timer’).text((new Date – start) / 1000 + ” Seconds”); }, 1000);

Timing algorithm: clock() vs time() in C++

March 7, 2023 by Tarik

<chrono> would be a better library if you’re using C++11. #include <iostream> #include <chrono> #include <thread> void f() { std::this_thread::sleep_for(std::chrono::seconds(1)); } int main() { auto t1 = std::chrono::high_resolution_clock::now(); f(); auto t2 = std::chrono::high_resolution_clock::now(); std::cout << “f() took ” << std::chrono::duration_cast<std::chrono::milliseconds>(t2-t1).count() << ” milliseconds\n”; } Example taken from here.

Time in milliseconds in C

March 4, 2023 by Tarik

Yes, this program has likely used less than a millsecond. Try using microsecond resolution with timeval. e.g: #include <sys/time.h> struct timeval stop, start; gettimeofday(&start, NULL); //do stuff gettimeofday(&stop, NULL); printf(“took %lu us\n”, (stop.tv_sec – start.tv_sec) * 1000000 + stop.tv_usec – start.tv_usec); You can then query the difference (in microseconds) between stop.tv_usec – start.tv_usec. Note that … Read more

clock_gettime alternative in Mac OS X

February 20, 2023 by Tarik

After hours of perusing different answers, blogs, and headers, I found a portable way to get the current time: #include <time.h> #include <sys/time.h> #ifdef __MACH__ #include <mach/clock.h> #include <mach/mach.h> #endif struct timespec ts; #ifdef __MACH__ // OS X does not have clock_gettime, use clock_get_time clock_serv_t cclock; mach_timespec_t mts; host_get_clock_service(mach_host_self(), CALENDAR_CLOCK, &cclock); clock_get_time(cclock, &mts); mach_port_deallocate(mach_task_self(), cclock); … Read more

Is it legal for a C++ optimizer to reorder calls to clock()?

February 20, 2023 by Tarik

Well, there is something called Subclause 5.1.2.3 of the C Standard [ISO/IEC 9899:2011] which states: In the abstract machine, all expressions are evaluated as specified by the semantics. An actual implementation need not evaluate part of an expression if it can deduce that its value is not used and that no needed side effects are … Read more

WSL2 Clock is out of sync with Windows

February 13, 2023 by Tarik

In case anyone finds this via search and doesn’t notice that there is actually a solution listed in the question, you can fix WSL clock drift via. sudo hwclock -s If you just need to do it occasionally, this is a fine solution. If you need to do it more frequently, consider @piouson’s solution

What happened to clockless computer chips?

February 7, 2023 by Tarik

Here’s an article from a few years ago that’s gung-ho on the technology, but I think the answer can be found in this quote: Why, for example, did Intel scrap its asynchronous chip? The answer is that although the chip ran three times as fast and used half the electrical power as clocked counterparts, that … Read more

C++ obtaining milliseconds time on Linux — clock() doesn’t seem to work properly

January 5, 2023 by Tarik

#include <sys/time.h> #include <stdio.h> #include <unistd.h> int main() { struct timeval start, end; long mtime, seconds, useconds; gettimeofday(&start, NULL); usleep(2000); gettimeofday(&end, NULL); seconds = end.tv_sec – start.tv_sec; useconds = end.tv_usec – start.tv_usec; mtime = ((seconds) * 1000 + useconds/1000.0) + 0.5; printf(“Elapsed time: %ld milliseconds\n”, mtime); return 0; }