git.sesse.net Git - nageru/blob - quittable_sleeper.h

   1 #ifndef _QUITTABLE_SLEEPER
   2 #define _QUITTABLE_SLEEPER 1
   3
   4 // A class that assists with fast shutdown of threads. You can set
   5 // a flag that says the thread should quit, which it can then check
   6 // in a loop -- and if the thread sleeps (using the sleep_* functions
   7 // on the class), that sleep will immediately be aborted.
   8 //
   9 // All member functions on this class are thread-safe.
  10
  11 #include <chrono>
  12 #include <mutex>
  13
  14 class QuittableSleeper {
  15 public:
  16         void quit()
  17         {
  18                 std::lock_guard<std::mutex> l(mu);
  19                 should_quit_var = true;
  20                 quit_cond.notify_all();
  21         }
  22
  23         void unquit()
  24         {
  25                 std::lock_guard<std::mutex> l(mu);
  26                 should_quit_var = false;
  27         }
  28
  29         bool should_quit() const
  30         {
  31                 std::lock_guard<std::mutex> l(mu);
  32                 return should_quit_var;
  33         }
  34
  35         template<class Rep, class Period>
  36         void sleep_for(const std::chrono::duration<Rep, Period> &duration)
  37         {
  38                 std::chrono::steady_clock::time_point t =
  39                         std::chrono::steady_clock::now() +
  40                         std::chrono::duration_cast<std::chrono::steady_clock::duration>(duration);
  41                 sleep_until(t);
  42         }
  43
  44         template<class Clock, class Duration>
  45         void sleep_until(const std::chrono::time_point<Clock, Duration> &t)
  46         {
  47                 std::unique_lock<std::mutex> lock(mu);
  48                 quit_cond.wait_until(lock, t, [this]{
  49                         return should_quit_var;
  50                 });
  51         }
  52
  53 private:
  54         mutable std::mutex mu;
  55         bool should_quit_var = false;
  56         std::condition_variable quit_cond;
  57 };
  58
  59 #endif  // !defined(_QUITTABLE_SLEEPER)