inline future<HostIterator> copy_to_host_async(DeviceIterator first,
DeviceIterator last,
HostIterator result,
command_queue &queue)
{
typedef typename
std::iterator_traits<DeviceIterator>::value_type
value_type;
size_t count = iterator_range_size(first, last);
if(count == 0){
return future<HostIterator>();
}
const buffer &buffer = first.get_buffer();
size_t offset = first.get_index();
event event_ =
queue.enqueue_read_buffer_async(buffer,
offset * sizeof(value_type),
count * sizeof(value_type),
::boost::addressof(*result));
return make_future(iterator_plus_distance(result, count), event_);
}
inline DeviceIterator copy_to_device(HostIterator first,
HostIterator last,
DeviceIterator result,
command_queue &queue,
const wait_list &events)
{
typedef typename
std::iterator_traits<DeviceIterator>::value_type
value_type;
typedef typename
std::iterator_traits<DeviceIterator>::difference_type
difference_type;
size_t count = iterator_range_size(first, last);
if(count == 0){
return result;
}
size_t offset = result.get_index();
queue.enqueue_write_buffer(result.get_buffer(),
offset * sizeof(value_type),
count * sizeof(value_type),
::boost::addressof(*first),
events);
return result + static_cast<difference_type>(count);
}
inline DeviceIterator copy_to_device_map(HostIterator first,
HostIterator last,
DeviceIterator result,
command_queue &queue,
const wait_list &events)
{
typedef typename
std::iterator_traits<DeviceIterator>::value_type
value_type;
typedef typename
std::iterator_traits<DeviceIterator>::difference_type
difference_type;
size_t count = iterator_range_size(first, last);
if(count == 0){
return result;
}
size_t offset = result.get_index();
// map result buffer to host
value_type *pointer = static_cast<value_type*>(
queue.enqueue_map_buffer(
result.get_buffer(),
CL_MAP_WRITE,
offset * sizeof(value_type),
count * sizeof(value_type),
events
)
);
// copy [first; last) to result buffer
std::copy(first, last, pointer);
// unmap result buffer
boost::compute::event unmap_event = queue.enqueue_unmap_buffer(
result.get_buffer(),
static_cast<void*>(pointer)
);
unmap_event.wait();
return result + static_cast<difference_type>(count);
}