1 #ifndef THREAD_POOL_H_

2 #define THREAD_POOL_H_

3

4 #include <list>

5 #include <functional>

6 #include <thread>

7 #include <mutex>

8 #include <condition_variable>

9

10 class ThreadPool {

11 private:

12 int num_threads;

13 std::thread *thread; // array of threads

14

15 struct WorkItem {

16 std::function<void ()> work;

17 std::function<void ()> done;

18 };

19

20 int qsize;

21 std::list<WorkItem> workq;

22 mutable std::mutex workq_mutex;

23 std::condition_variable workq_condvar;

24

25 int nactive; // number of active workers (not sleeping)

26

27 // condvar used by wait

28 std::condition_variable done_condvar;

29

30 bool quit;

31

32 void thread_func();

33

34 public:

35 ThreadPool(int num_threads = -1);

36 ~ThreadPool();

37

38 void add_work(std::function<void ()> func);

39 void add_work(std::function<void ()> work_func, std::function<void ()> done_func);

40

41 // returns the number of queued work items

42 int queued() const;

43 // returns the number of active threads

44 int active() const;

45 // returns number of pending work items (both in the queue and active)

46 int pending() const;

47

48 // waits for all work to be completed

49 long wait();

50 long wait(long timeout);

51 };

52

53 #endif // THREAD_POOL_H_