double_buffer.h

Go to the documentation of this file.

#ifndef LIPH_DOUBLE_BUFFER_H_
#define LIPH_DOUBLE_BUFFER_H_
 
#include <atomic>
#include <memory>
 
namespace liph {
 
template <class T>
class double_buffer {
public:
    template <class... Args>
    double_buffer(Args&&...args) : v0_(std::forward<Args>(args)...), v1_(std::forward<Args>(args)...) {}
 
    const T& get() const { return *pv_[idx_]; }
    T& get_free() const { return *pv_[1 - idx_]; }
    void swap() { idx_ = 1 - idx_; };
 
private:
    T v0_;
    T v1_;
    T *pv_[2]{&v0_, &v1_};
    std::atomic<int> idx_{0};
};
 
/* #if __cplusplus < 202002L */
 
template <class T>
class double_buffer_with_shared_ptr {
public:
    std::shared_ptr<T> get() const { return std::atomic_load(&v0_); }
 
    template <class... Args>
    std::shared_ptr<T> get_free(Args&&...args) {
        v1_ = std::make_shared<T>(std::forward<Args>(args)...);
        return v1_;
    }
 
    void swap() { std::atomic_store(&v0_, v1_); }
 
private:
    std::shared_ptr<T> v0_;
    std::shared_ptr<T> v1_;
};
 
/* #else  // C++20 */
 
/* template <class T> */
/* class double_buffer_with_shared_ptr { */
/* public: */
/*     std::shared_ptr<T> Get() const { return v0_; } */
 
/*     template <class... Args> */
/*     std::shared_ptr<T> GetFree(Args&&...args) { */
/*         v1_ = std::make_shared<T>(std::forward<Args>(args)...); */
/*         return v1_; */
/*     } */
 
/*     void Switch() { v0_ = v1_; } */
 
/* private: */
/*     std::atomic<std::shared_ptr<T> > v0_; */
/*     std::atomic<std::shared_ptr<T> > v1_; */
/* }; */
 
/* #endif */
 
}  // namespace liph
 
#endif  // LIPH_DOUBLE_BUFFER_H_