Wake up a std::thread from usleep

Question

Consider the following example:

#include 
#include 
#include 

#include 
#include 

         


        

Answer 1

Sleep for a short amount of time and look to see if a variable has changed.

#include 
#include 
#include 

std::atomic sharedVar(1);
void sleepy()
{
    while (sharedVar.load())
    {
        usleep(500);
    }
}

int main()
{
    std :: thread sleepy_thread(sleepy);
    // wake up
    sharedVar.store(0);
}