Class context

compute/include/boost/compute/context.hpp:48–227

\class context \brief A compute context. The context class represents a compute context. A context object manages a set of OpenCL resources including memory buffers and program objects. Before allocating memory on the device or executing kernels you must set up a context object. To create a context for the default device on the system: \code // get the default compute device boost::compute::dev

///
/// \see device, command_queue
class context
{
public:
    /// Create a null context object.
    context()
        : m_context(0)
    {
    }

    /// Creates a new context for \p device with \p properties.
    ///
    /// \see_opencl_ref{clCreateContext}
    explicit context(const device &device,
                     const cl_context_properties *properties = 0)
    {
        BOOST_ASSERT(device.id() != 0);

        cl_device_id device_id = device.id();

        cl_int error = 0;
        m_context = clCreateContext(properties, 1, &device_id, 0, 0, &error);

        if(!m_context){
            BOOST_THROW_EXCEPTION(opencl_error(error));
        }
    }

    /// Creates a new context for \p devices with \p properties.
    ///
    /// \see_opencl_ref{clCreateContext}
    explicit context(const std::vector<device> &devices,
                     const cl_context_properties *properties = 0)
    {
        BOOST_ASSERT(!devices.empty());

        cl_int error = 0;

        m_context = clCreateContext(
            properties,
            static_cast<cl_uint>(devices.size()),
            reinterpret_cast<const cl_device_id *>(&devices[0]),
            0,
            0,
            &error
        );

        if(!m_context){
            BOOST_THROW_EXCEPTION(opencl_error(error));
        }
    }

    /// Creates a new context object for \p context. If \p retain is
    /// \c true, the reference count for \p context will be incremented.
    explicit context(cl_context context, bool retain = true)
        : m_context(context)
    {
        if(m_context && retain){
            clRetainContext(m_context);