线程池的实现

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

using namespace std;

class ThreadPool {
public:
	ThreadPool(int numThreads):m_stop(false){
		for (int i = 0; i < numThreads; ++i) {
			threads.emplace_back([this] {
				while (1) {
					unique_lock<mutex> lock(m_mtx);
					m_cv.wait(lock, [this] {
						return !tasks.empty() || m_stop;
					});

					if (m_stop && tasks.empty())
					{
						return;
					}

					std::function<void()> task(std::move(tasks.front()));
					tasks.pop();
					lock.unlock();
					task();
				}
			});
		}
	}

	~ThreadPool() {
		{
			unique_lock<mutex> lock(m_mtx);
			m_stop = true;
		}
		m_cv.notify_all();
		for (auto& t : threads)
		{
			t.join();
		}
	}

	template<typename F, class... Args>
	void enQueue(F &&f, Args&&... args) {
		function<void()> task = 
			bind(forward<F>(f), forward<Args>((args)...));
		{
			unique_lock<mutex> lock(m_mtx);
			tasks.emplace(move(task));
		}

		m_cv.notify_one();
	}
private:
	vector<thread> threads;
	queue<function<void()> > tasks;

	mutex m_mtx;
	condition_variable m_cv;

	bool m_stop;
};





int main(){
	ThreadPool pool(4);
	for (size_t i = 0; i < 10; i++)
	{
		pool.enQueue([i] {
			cout << "task:" << i << "is running" << endl;
		});
	}


	system("pause");
	return 0;
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86