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  1. #include<algorithm>
  2. #include<atomic>
  3. #include<exception>
  4. #include<iostream>
  5. #include<memory>
  6. #include<stdexcept>
  7. #include<thread>
  8. #include<utility>
  9. #include<vector>
  10. using namespace std;
  11.  
  12. class thr_stack
  13. {
  14. 	struct Node
  15. 	{
  16. 		int data;
  17. 		std::shared_ptr<Node> next;
  18. 		Node(const std::shared_ptr<Node> &next_,int data_)
  19. 			:data{data_},next{next_}{}
  20. 	};
  21. 	std::shared_ptr<Node> begin_;
  22. public:
  23. 	void emplace(int data)
  24. 	{
  25. 		begin_=std::make_shared<Node>(begin_,data);
  26. 	}
  27. 	int pop()
  28. 	{
  29. 		std::shared_ptr<Node> node{std::atomic_load(&begin_)};
  30. 		while(node&&!std::atomic_compare_exchange_weak_explicit(&begin_,&node,node->next
  31. 			  ,std::memory_order_seq_cst
  32. 			  ,std::memory_order_seq_cst))
  33. 			;
  34. 		if(node)
  35. 			return node->data;
  36. 		throw logic_error{"nullptr"};
  37. 	}
  38. 	~thr_stack()
  39. 	{
  40. 		while(begin_)
  41. 		{
  42. 			std::shared_ptr<Node> p{std::move(begin_->next)};
  43. 			begin_.reset();
  44. 			begin_=std::move(p);
  45. 		}
  46. 	}
  47. };
  48.  
  49. constexpr int max_num{1000000};
  50. thr_stack stack;
  51. vector<atomic<int>> vec(max_num);
  52.  
  53. void read_test(int);
  54.  
  55. int main()
  56. {
  57. 	for(int i{0};i!=max_num;++i)
  58. 		stack.emplace(i);
  59. #if 1	//the problem here
  60. 	const unsigned int thread_count{std::thread::hardware_concurrency()};
  61. 	vector<thread> thr;
  62. 	for(unsigned int i{0};i!=thread_count;++i)
  63. 		thr.emplace_back(read_test,max_num/thread_count);
  64. 	for(unsigned int i{0};i!=thread_count;++i)
  65. 		thr[i].join();
  66. #else
  67. 	read_test(max_num);
  68. #endif
  69. 	if(all_of(begin(vec),end(vec),[](auto &val){return val==1;}))
  70. 		cout<<"succeed"<<endl;
  71. }
  72.  
  73. void read_test(int count)
  74. {
  75. 	try
  76. 	{
  77. 		for(int i{0};i!=count;++i)
  78. 			++vec.at(stack.pop());
  79. 	}catch(const exception &e)
  80. 	{
  81. 		cerr<<e.what()<<endl;	//cannot catch anything
  82. 	}
  83. }
Success #stdin #stdout 0.5s 67392KB
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https://ideone.com/dmc08e
language:
C++14 (gcc 8.3)
created:
9 years ago
visibility:
public

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