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  1. // Type your code here, or load an example.
  2. #include <iostream>
  3. #include <numeric>
  4. #include <string>
  5. #include <mutex>
  6. #include <thread>
  7.  
  8. template <class T>
  9. class   SharedVariable {
  10. private:
  11.     std::mutex  mtx;
  12.     T           data;
  13. public:
  14.     T   Get(void) {
  15.         T       data_cpy;
  16.         std::lock_guard<std::mutex> lck(mtx);
  17.         data_cpy = this->data;
  18.         return data_cpy;
  19.     }
  20.     void Set(const T data) {
  21.         std::lock_guard<std::mutex> lck(mtx);
  22.         this->data = data;
  23.     }
  24. };    
  25.  
  26. void func(int & i ,std::mutex & mtx) {
  27.     std::lock_guard<std::mutex> lck(mtx);
  28.     int tmp = i;
  29.     std::this_thread::yield();
  30.     i = tmp +1 ;
  31. }
  32.  
  33. void func2(SharedVariable<int> & sv_int) {
  34.     int tmp = sv_int.Get();
  35.     std::this_thread::yield();
  36.     sv_int.Set(tmp +1);
  37. }
  38.  
  39. #define TH_NUM 8
  40.  
  41. void func_test(){
  42.     int x = 0 ;
  43. 	std::mutex mtx ;
  44. 	bool strt_flag = false;
  45. 	std::thread t [TH_NUM];
  46.     for (size_t i = 0 ;i < TH_NUM;++i) { 
  47.         t[i] = std::thread([&]() {
  48.             while(!strt_flag);
  49.             func(x , mtx);
  50.         });
  51.  
  52.     }
  53.     strt_flag = true;
  54.     for (int i = 0 ;i<TH_NUM ;++i) {
  55.  
  56.     	t[i].join();
  57.  
  58.     } 
  59.     std::cout<<"x = "<< x <<std::endl;
  60. }
  61.  
  62. void func2_test(){
  63.     SharedVariable<int> sv_int;
  64.     sv_int.Set(0);
  65.     std::thread t [TH_NUM];
  66.     bool strt_flag = false;
  67.     for (size_t i = 0 ;i < TH_NUM;++i) { 
  68.         t[i] = std::thread([&]() {
  69.             while(!strt_flag);
  70.             func2(sv_int);
  71.         });
  72.     }
  73.     strt_flag = true;
  74.     for (size_t i = 0 ;i < TH_NUM;++i) { 
  75.         t[i].join();
  76.     }
  77.     std::cout<<"sv_int = "<< sv_int.Get() <<std::endl;
  78. }
  79.  
  80.  
  81. int main () {
  82.     func_test();
  83.     func2_test();
  84.  
  85.     return 0;
  86. }
Success #stdin #stdout 0s 4392KB
comments ()
stdin
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Standard input is empty
stdout
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x = 8
sv_int = 4
https://ideone.com/wHfCXi
language:
C++ (gcc 8.3)
created:
4 years ago
visibility:
public

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