multithreading - Threads handling in C++ 11 -

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i have base class, manages threaded functions , derived, can set it's functions run concurrently of base class. during test in emulating fast starts/stops of function, programs crashes. seems, problem in mutexes can wrong. problem?

class threadedbase { public:     threadedbase(){}     virtual ~threadedbase() {         (int = 0; < m_threadedtasks.size(); ++i) {             *m_threadedtasks[i]->run = false;             m_threadedtasks[i]->thread->join();         }          while (m_threadedtasks.size()) {             m_threadedtasks.erase(m_threadedtasks.begin());         }     }      void addtask(std::function<void()> f) {         static int = 0;         m_threadedtasks.insert({ i++, new threadedtask(f)});     }      void startn(int n) {         std::lock_guard<std::mutex> lock(m_threadedtasks[n]->mtx);         std::cout << "startn\n";         if (*m_threadedtasks[n]->run == true) return;         *m_threadedtasks[n]->run = true;          m_threadedtasks[n]->thread = new std::thread((std::mem_fn(&threadedbase::run)), this, n);     }      void stopn(int n) {         std::lock_guard<std::mutex> lock(m_threadedtasks[n]->mtx);         std::cout << "stopn\n";         *m_threadedtasks[n]->run = false;     }  private:     struct threadedtask     {         threadedtask(std::function<void()> f) : function(f), thread(nullptr), run(new bool(false)) {}         ~threadedtask() {             thread->join();             delete thread;             delete run;         }         std::function<void()> function;         std::thread *thread;         mutable std::mutex mtx;         bool *run;     };     std::unordered_map<int, threadedtask*> m_threadedtasks;      void run(int n) {         while (*m_threadedtasks[n]->run) {             std::lock_guard<std::mutex> lock(m_threadedtasks[n]->mtx);             m_threadedtasks[n]->function();             std::cout << "yet loop\n";         }          // todo: erase if needed         std::lock_guard<std::mutex> lock(m_threadedtasks[n]->mtx);         *m_threadedtasks[n]->run = false;         delete m_threadedtasks[n]->thread;         m_threadedtasks[n]->thread = nullptr;     } };  class test : public threadedbase { public:     test() : threadedbase() {         addtask(std::bind(std::mem_fn(&test::threadedblock1), this));         addtask(std::bind(std::mem_fn(&test::threadedblock2), this));     };     void threadedblock1() {         std::this_thread::sleep_for(std::chrono::milliseconds(200));         std::cout << "task1 finished ";     }     void threadedblock2() {         std::this_thread::sleep_for(std::chrono::milliseconds(200));         std::cout << "task2 finished ";     }     ~test() { std::cout << "deleting\n"; }      void startn(int n) {         threadedbase::startn(n);     }     void stopn(int n) {         threadedbase::stopn(n);     } };  int main() {     test *t = new test();      srand(time(null));     while (true) {         (0 + rand() % 2 == 0) ? t->startn(0) : t->stopn(0);     }      std::this_thread::sleep_for(std::chrono::seconds(100));      return 0; }

thank's joachim pileborg i've made code work. following:

class threadedbase { public:     threadedbase(){}     virtual ~threadedbase() {         (int = 0; < m_threadedtasks.size(); ++i) {             m_threadedtasks[i]->run = false;             m_threadedtasks[i]->thread.join();         }          while (m_threadedtasks.size()) {             m_threadedtasks.erase(m_threadedtasks.begin());         }     }      void addtask(std::function<void()> f) {         static int = 0;         m_threadedtasks.insert({ i++, new threadedtask(f) });     }      void startn(int n) {         std::lock_guard<std::mutex> lock(m_threadedtasks[n]->mtx);         if (m_threadedtasks[n]->run == true) return;         m_threadedtasks[n]->run = true;         m_threadedtasks[n]->thread = std::thread(&threadedbase::run, this, n);     }      void stopn(int n) {         m_threadedtasks[n]->run = false;         if (m_threadedtasks[n]->thread.joinable())             m_threadedtasks[n]->thread.join();     }  private:     struct threadedtask     {         threadedtask(std::function<void()> f) : function(f), thread(), mtx(), run(false) {}         ~threadedtask() {             thread.join();         }         std::function<void()> function;         std::thread thread;         mutable std::mutex mtx;         bool run;     };     std::unordered_map<int, threadedtask*> m_threadedtasks;      void run(int n) {         while (m_threadedtasks[n]->run) {             std::lock_guard<std::mutex> lock(m_threadedtasks[n]->mtx);             m_threadedtasks[n]->function();             std::cout << "yet loop\n";         }         // todo: erase if needed         m_threadedtasks[n]->run = false;     } };  class test : public threadedbase { public:     test() : threadedbase() {         addtask(std::bind(&test::threadedblock1, this));         addtask(std::bind(&test::threadedblock2, this));     };     void threadedblock1() {         std::this_thread::sleep_for(std::chrono::milliseconds(5));         std::cout << "task1 finished ";     }     void threadedblock2() {         std::this_thread::sleep_for(std::chrono::milliseconds(5));         std::cout << "task2 finished ";     }     ~test() { std::cout << "deleting\n"; }      void startn(int n) {         threadedbase::startn(n);     }     void stopn(int n) {         threadedbase::stopn(n);     } };  int main() {     test *t = new test();      srand(time(null));     while (true) {         (0 + rand() % 2 == 0) ? t->startn(0) : t->stopn(0);     }      std::this_thread::sleep_for(std::chrono::seconds(100));      return 0; }

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