Using setInterval() in C++

Question

In JavaScript, there is a function called setInterval(). Can it be achieved in C++? If a loop is used, the program does not continue but keeps calling the function.

Answer 1

Use std::thread to achieve.

// <thread> should have been included
void setInterval(auto function,int interval) {
    thread th([&]() {
        while(true) {
            Sleep(interval);
            function();
        }
    });
    th.detach();
}
//...
setInterval([]() {
    cout<<"1 sec past\n";
},
1000);

Answer 2

There is no built in setInterval in C++. you can imitate this function with asynchronous function:

template <class F, class... Args>
void setInterval(std::atomic_bool& cancelToken,size_t interval,F&& f, Args&&... args){
  cancelToken.store(true);
  auto cb = std::bind(std::forward<F>(f),std::forward<Args>(args)...);
  std::async(std::launch::async,[=,&cancelToken]()mutable{
     while (cancelToken.load()){
        cb();
        std::this_thread::sleep_for(std::chrono::milliseconds(interval));
     }
  });
}

use cancelToken to cancel the interval with

cancelToken.store(false);

do notice though, that this mchanism construct a new thread for the task. it is not usable for many interval functions. in this case, I'd use already written thread-pool with some sort of time-measurment mechanism.

Edit : example use:

int main(int argc, const char * argv[]) {
    std::atomic_bool b;
    setInterval(b, 1000, printf, "hi there\n");
    getchar();
}