I'm trying to allocated pinned memory (floats) on the host as per page 10 of
https://www.nvidia.com/content/cudazone/CUDABrowser/downloads/papers/NVIDIA_OpenCL_BestPracticesGuide.pdf .
So I want to get a direct FloatBuffer that is backed by memory allocated from clCreateBuffer with CL_MEM_ALLOC_HOST_PTR.
I scoured through the source of CLContext and found that all createXBuffer calls eventually boil down to:
(1)
public final CLBuffer<?> createBuffer(final int size, final int flags) {
final CLBuffer<?> buffer = CLBuffer.create(this, size, flags);
memoryObjects.add(buffer);
return buffer;
}
or
(2)
public final
CLBuffer createBuffer(final B directBuffer, final int flags) {
final CLBuffer buffer = CLBuffer.create(this, directBuffer, flags);
memoryObjects.add(buffer);
return buffer;
}
My understanding is that (1) will get me a CLBuffer which has a null Buffer, so this is not what I want. And (2) will not work with a null argument for directBuffer as it calls CLBuffer.create:
(3)
static CLBuffer create(final CLContext context, final B directBuffer, final int flags) {
if(!directBuffer.isDirect()) <---------------------------------------------------- NullPointerException here
throw new IllegalArgumentException("buffer is not direct");
B host_ptr = null;
if(isHostPointerFlag(flags)) {
host_ptr = directBuffer;
}
final CLBufferBinding binding = context.getPlatform().getBufferBinding();
final int[] result = new int[1];
final int size = Buffers.sizeOfBufferElem(directBuffer) * directBuffer.capacity();
final long id = binding.clCreateBuffer(context.ID, flags, size, host_ptr, result, 0);
CLException.checkForError(result[0], "can not create cl buffer");
return new CLBuffer(context, directBuffer, size, id, flags);
}
As a side note I don't think that (2) or (3) should accept Mem.ALLOCATE_BUFFER as the buffer passed is already allocated... or am I missing something?
How would I go about getting a NIO buffer into a memory block allocated by clCreateBuffer with CL_MEM_ALLOC_HOST_PTR?
Locked
