Calling a function for each second

[Hasala]

In my program I want to call a function for each second. Once the function has been called it should be called again after an exact second. Like this I want to call the function for each second.
How can this be done? I tried with the function clock() in <ctime> as well. It didn't work since it didn't allow me to measure the time duration of a second in an accurate manner.
Please help me on this.

Thanks in Advance!

[Cubbi]

1. modern compiler option: spawn a thread that runs an endless loop that sleeps for one second and calls your function

#include <thread>
#include <chrono>
void fn()
{
    for(;;)
   {
        std::this_thread::sleep_for(std::chrono::seconds(1));
        // <-- call your function here
   }
}
int main()
{
    std::thread(fn).detach();
    // <- do something that takes more than a second here
}

2. any compiler option: start a boost.asio timer with a callback that is your function: here's a tutorial http://www.boost.org/doc/libs/1_49_0/doc/html/boost_asio/tutorial/tuttimer2.html

3. for completeness: use system-specific timer API (e.g. setitimer() on POSIX) and write a signal handler (e.g. SIGALRM on POSIX) that calls your function.

Note that all options have varying degrees of precision, and nothing gives the absolute "exact second".

[viliml]

If you don't have c++11:

#include <ctime>

using namespace std;

int main()
{
     int a=clock()/CLOCKS_PER_SEC;//this gets the time in sec.
     while(true)
     {
           while(clock()/CLOCKS_PER_SEC-a<1);
           //call your function
           a=clock()/CLOCKS_PER_SEC;
           }
     }