1 #include "threadpool.h"

2

3 ThreadPool::ThreadPool(int num_threads)

4 {

5 quit = false;

6

7 if(num_threads == -1) {

8 num_threads = std::thread::hardware_concurrency();

9 }

10

11 printf("creating thread pool with %d threads\n", num_threads);

12

13 thread = new std::thread[num_threads];

14 for(int i=0; i<num_threads; i++) {

15 thread[i] = std::thread(&ThreadPool::thread_func, this);

16 }

17 this->num_threads = num_threads;

18 }

19

20 ThreadPool::~ThreadPool()

21 {

22 quit = true;

23 condvar.notify_all();

24

25 printf("ThreadPool: waiting for %d worker threads to stop ", num_threads);

26 fflush(stdout);

27 for(int i=0; i<num_threads; i++) {

28 thread[i].join();

29 putchar('.');

30 fflush(stdout);

31 }

32 putchar('\n');

33 }

34

35 void ThreadPool::add_work(std::function<void ()> func)

36 {

37 std::unique_lock<std::mutex> lock(workq_mutex);

38 workq.push_back(func);

39 }

40

41 void ThreadPool::thread_func()

42 {

43 std::unique_lock<std::mutex> lock(workq_mutex);

44 for(;;) {

45 if(quit) break;

46

47 condvar.wait(lock);

48

49 if(!quit && !workq.empty()) {

50 std::function<void ()> work = workq.front();

51 workq.pop_front();

52 lock.unlock();

53

54 work();

55

56 lock.lock();

57 }

58 }

59 }