fork(7) download 
  1. #include <iostream>
  2. #include <thread>
  3. #include <iostream>
  4. #include <condition_variable>
  5. #include <list>
  6.  
  7. using namespace std;
  8.  
  9. class Worker
  10. {
  11. public:
  12. 	Worker(bool run) : m_Running(run) { if (run) private_start(); }
  13. 	Worker() : m_Running(false) { }
  14. 	~Worker() { stop(); }
  15.  
  16. 	template<typename... Args>
  17. 	void push_task(Args&&... args)
  18. 	{
  19. 		{
  20. 			std::lock_guard<std::mutex> lk(m_Mutex);
  21. 			m_Queue.push_back(std::bind(std::forward<Args>(args)...));
  22. 		}
  23.  
  24. 		m_Condition.notify_all();
  25. 	}
  26.  
  27. 	void start()
  28. 	{
  29. 		{
  30. 			std::lock_guard<std::mutex> lk(m_Mutex);
  31. 			if (m_Running == true) return;
  32. 			m_Running = true;
  33. 		}
  34.  
  35. 		private_start();
  36. 	}
  37.  
  38. 	void stop()
  39. 	{
  40. 		{
  41. 			std::lock_guard<std::mutex> lk(m_Mutex);
  42. 			if (m_Running == false) return;
  43. 			m_Running = false;
  44. 		}
  45.  
  46. 		m_Condition.notify_all();
  47. 		m_Thread.join();
  48. 	}
  49.  
  50. private:
  51. 	void private_start()
  52. 	{
  53. 		m_Thread = std::thread([this]
  54. 		{
  55. 			for (;;)
  56. 			{
  57. 				decltype(m_Queue) local_queue;
  58. 				{
  59. 					std::unique_lock<std::mutex> lk(m_Mutex);
  60. 					m_Condition.wait(lk, [&] { return !m_Queue.empty() + !m_Running; });
  61.  
  62. 					if (!m_Running)
  63. 					{
  64. 						for (auto& func : m_Queue)
  65. 							func();
  66.  
  67.                         m_Queue.clear();
  68. 						return;
  69. 					}
  70.  
  71. 					std::swap(m_Queue, local_queue);
  72. 				}
  73.  
  74. 				for (auto& func : local_queue)
  75. 					func();
  76. 			}
  77. 		});
  78. 	}
  79.  
  80. private:
  81. 	std::condition_variable m_Condition;
  82. 	std::list<std::function<void()>> m_Queue;
  83. 	std::mutex m_Mutex;
  84. 	std::thread m_Thread;
  85. 	bool m_Running = false;
  86. };
  87.  
  88. void do_work(unsigned id)
  89. {
  90. 	// uncomment if you want to sync the output stream
  91. 	// static std::mutex cout_mutex;
  92. 	// std::lock_guard<std::mutex> lk(cout_mutex);
  93. 	std::cout << id << std::endl;
  94. }
  95.  
  96. int main()
  97. {
  98. 	{
  99. 		Worker workers[3];
  100. 		int counter = 0;
  101.  
  102. 		for (auto& worker : workers)
  103. 			worker.start();
  104.  
  105. 		for (auto& worker : workers)
  106. 		{
  107. 			for (int i = 0; i < 5; i++)
  108. 				worker.push_task(do_work, ++counter + i);
  109. 		}
  110. 	}
  111.  
  112. 	std::cout << "finish" << std::endl;
  113. 	getchar();
  114.  
  115. 	return 0;
  116. }
Success #stdin #stdout 0s 28048KB
comments (?)
stdin 
Standard input is empty
stdout 
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finish
https://ideone.com/ARbq5O
language:
C++14 (gcc 8.3)
created:
9 years ago
visibility:
public

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