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Fixed time step

12345678910111213141516#include <chrono> #include <thread> using namespace std::literals::chrono_literals; void some_complex_work(); int main() { using clock = std::chrono::steady_clock; clock::time_point next_time_point = clock::now() + 5s; some_complex_work(); std::this_thread::sleep_until(next_time_point); }

This sample is licensed under the CC0 Public Domain Dedication.

Intent

Block the execution of a thread until a fixed point in time.

Description

For the purposes of this sample, we use std::chrono::steady_clock (line 10), although any other clock will suffice.

On line 11, we create a clock::time_point representing the point in time five seconds from now. To do so, we use clock::now() to get the current time point and add the duration of 5s to it. Here we have used one of C++14’s duration literal suffixes to representing a duration with the seconds suffix, s. The using directive on line 4 is required in order to use these suffixes. For C++11, the duration can be constructed manually.

After performing some complex work on line 13, we then call std::this_thread::sleep_until on line 15, passing it the time point we computed earlier. This blocks the current thread until we have reached that time point, ensuring that execution continues exactly five seconds after the starting time, regardless of how much time the complex work took (unless it took more than five seconds).

This technique is most commonly used in a loop to ensure that the loop iterates with a fixed time step. Alternatively, if you want to sleep for a fixed amount of time, see the sleep sample.

Contributors

  • Joseph Mansfield

Last Updated

26 September 2015

Source

Fork this sample on GitHub

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