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 }

18

19 ThreadPool::~ThreadPool()

20 {

21 quit = true;

22 condvar.notify_all();

23

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

25 fflush(stdout);

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

27 thread[i].join();

28 putchar('.');

29 fflush(stdout);

30 }

31 putchar('\n');

32 }

33

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

35 {

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

37 workq.push_back(func);

38 }

39

40 void ThreadPool::thread_func()

41 {

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

43 for(;;) {

44 if(quit) break;

45

46 condvar.wait(lock);

47

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

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

50 workq.pop_front();

51 lock.unlock();

52

53 work();

54

55 lock.lock();

56 }

57 }

58 }