Class IThreadContext

quantum/interface/quantum_ithread_context.h:37–245

/// @tparam RET The type of value returned via the promise associated with this context.
template <class RET>
struct IThreadContext : public IThreadContextBase
{
    using ContextTag = ThreadContextTag;
    using Ptr = std::shared_ptr<IThreadContext<RET>>;
    using Impl = Context<RET>;
    
    /// @brief Waits for the future associated with this context to be ready.
    /// @note Blocks until the future is ready or until an exception is thrown.
    virtual void wait() const = 0;
    
    /// @brief Waits for the future associated with this context to be ready for a maximum of 'timeMs' milliseconds.
    /// @param[in] timeMs The maximum amount of milliseconds to wait until the future value becomes ready.
    /// @return 'ready' if value was posted before duration expired or 'timeout' otherwise.
    /// @note Blocks until the value is ready, until 'timeMs' duration expires or until an exception is thrown.
    virtual std::future_status waitFor(std::chrono::milliseconds timeMs) const = 0;
    
    /// @brief Waits for the future in the 'num-th' continuation context to be ready.
    /// @details Allowed range for num is [-1, total_continuations). -1 is equivalent of calling wait() or
    ///          waitAt(total_continuations-1) on the last context in the chain (i.e. the context which is returned
    ///          via end()). Position 0 represents the first future in the chain.
    /// @param[in] num The number indicating which future to wait on.
    /// @note Blocks until the value is ready or an exception is thrown.
    virtual void waitAt(int num) const = 0;
    
    /// @brief Waits for the future in the 'num-th' continuation context to be ready for a maximum of 'timeMs' milliseconds.
    /// @details Allowed range for num is [-1, total_continuations). -1 is equivalent of calling wait() or
    ///          waitAt(total_continuations-1) on the last context in the chain (i.e. the context which is returned
    ///          via end()). Position 0 represents the first future in the chain.
    /// @param[in] num The number indicating which future to wait on.
    /// @param[in] timeMs The maximum amount of milliseconds to wait until the future value becomes ready.
    /// @return 'ready' if value was posted before duration expired or 'timeout' otherwise.
    /// @note Blocks until the value is ready, until 'timeMs' duration expires or until an exception is thrown.
    virtual std::future_status waitForAt(int num, std::chrono::milliseconds timeMs) const = 0;
    
    /// @brief Wait for all the futures in the continuation chain to be ready.
    /// @note Blocks until all future values are ready. If any future throws, the exception is swallowed.
    virtual void waitAll() const = 0;
    
    /// @brief Get the future value associated with this context.
    /// @note Blocks until the future is ready or until an exception is thrown. Once this function returns, the future
    ///       becomes invalidated (i.e. cannot be read again).
    template <class V = RET>
    NonBufferRetType<V> get();
    
    /// @brief Get a reference the future value associated with this context.
    /// @return A reference to the future value.
    /// @note Blocks until the future is ready or until an exception is thrown. Contrary to get(), this function does
    ///       not invalidate the future and as such may be read again.
    template <class V = RET>
    const NonBufferRetType<V>& getRef() const;
    
    /// @brief Get the future value from the 'num-th' continuation context.
    /// @details Allowed range for num is [-1, total_continuations). -1 is equivalent of calling get() or
    ///          getAt(total_continuations-1) on the last context in the chain (i.e. the context which is returned
    ///          via end()). Position 0 represents the first future in the chain.
    /// @tparam OTHER_RET The type of the future value associated with the 'num-th' context.
    /// @param[in] num The number indicating which future to wait on.
    /// @return The future value of the 'num-th' thread context.