CodeDweller/multitasking.hpp

#ifndef M_MultiTasking
#define M_MultiTasking

#include <cstddef>
#include <queue>

namespace CodeDweller {

class MultiTask {
  public:
    enum class State{Running, Waiting, Finished};
    virtual ~MultiTask() {}
    virtual State task() = 0;
};

class MultiTaskQueue : public std::queue<MultiTask*> {
  public:

    void put(MultiTask& T) { push(&T); }
    MultiTask& get() { MultiTask& T = *(front()); pop(); return T; }

};

class MultiTasker : public MultiTask {
  private:
    void processBatch(size_t n, MultiTaskQueue& q, bool StopOnWait = false);

  public:
    MultiTaskQueue working;
    MultiTaskQueue waiting;
    MultiTaskQueue finished;
    State task();

    bool isReady() { return (false == working.empty()); }
    bool isWaiting() { return (false == waiting.empty() && true == working.empty()); }
    bool isFinished() { return (true == working.empty() && true == waiting.empty()); }
    bool hasWork() { return (false == isFinished()); }

    size_t completed() { return finished.size(); }
    size_t pending() { return (working.size() + waiting.size()); }
    size_t total() { return (working.size() + waiting.size() + finished.size()); }

    void put(MultiTask& t) { working.put(t); }
    MultiTask& get() { return finished.get(); }
    bool canGet() { return (false == finished.empty()); }
};

}

#endif // M_MultiTasking