I wanted to write a quick and dirty code... but I didn't want to make it lousy in execution. Had simple requirement: Run a piece of code in a separate thread every 6 seconds but have ability to terminate (almost) immediately. Like any other lousy programmer, I didn't want to implement a timer (which is lengthy process in C++). So I stumbled upon a solution which uses std::future to terminate the sleep immediately and doesn't execute anything once the future times out. Even if I was using while loop instead of do..while, it would have come out of the scope immediately. I am publishing it here as my example is more clear and that "Bad bad code." is present in that solution. Happy programming!
to compile: > g++ -pthread test.cpp
#include <thread> #include <iostream> #include <assert.h> #include <chrono> #include <future> using namespace std; void threadFunction(std::future<void> future){ std::cout << "Starting the thread" << std::endl; do { std::cout << "Executing the thread....." << std::endl; //std::this_thread::sleep_for(std::chrono::milliseconds(6000)); //bad bad code } while (future.wait_for(std::chrono::milliseconds(6000)) == std::future_status::timeout); std::cout << "Thread Terminated" << std::endl; } main(){ std::promise<void> signal_exit; //create promise object std::future<void> future = signal_exit.get_future();//create future objects std::thread my_thread(&threadFunction, std::move(future)); //start thread, and move future std::this_thread::sleep_for(std::chrono::seconds(7)); //wait for 7 seconds std::cout << "Threads will be stopped soon...." << std::endl; signal_exit.set_value(); //set value into promise my_thread.join(); //join the thread with the main thread std::cout << "Doing task in main function" << std::endl; }
