Provided by: opencl-1.2-man-doc_1.0~svn22836-1.1_all 
NAME
clGetDeviceIDsFromD3D11KHR - Querying OpenCL Devices Corresponding to Direct3D 11 Devices.
cl_int clGetDeviceIDsFromD3D11KHR(cl_platform_id platform,
cl_d3d11_device_source_khr d3d_device_source,
void *d3d_object,
cl_d3d11_device_set_khr d3d_device_set,
cl_uint num_entries, cl_device_id *devices,
cl_uint *num_devices);
PARAMETERS
platform
Refers to the platform ID returned by clGetPlatformIDs(3clc).
d3d_device_source
Specifies the type of d3d_object and may be one of the following:.
┌──────────────────────────┬────────────────────┐
│cl_d3d_device_source_khr │ Type of d3d_object │
├──────────────────────────┼────────────────────┤
│CL_D3D11_DEVICE_KHR │ ID3D11Device * │
├──────────────────────────┼────────────────────┤
│CL_D3D11_DXGI_ADAPTER_KHR │ IDXGIAdapter * │
└──────────────────────────┴────────────────────┘
d3d_object
Specifies the object whose corresponding OpenCL devices are being queried. The type of
d3d_object must be as specified in the table above.
d3d_device_set
Specifies the set of devices to return, and must be one of the following:
┌───────────────────────────────────┬──────────────────────────────────┐
│cl_d3d_device_set_khr │ Devices returned in devices │
├───────────────────────────────────┼──────────────────────────────────┤
│CL_PREFERRED_DEVICES_FOR_D3D11_KHR │ The OpenCL devices associated │
│ │ with the specified Direct3D │
│ │ object. │
├───────────────────────────────────┼──────────────────────────────────┤
│CL_ALL_DEVICES_FOR_D3D11_KHR │ All OpenCL devices which may │
│ │ interoperate with the specified │
│ │ Direct3D object. Performance of │
│ │ sharing data on these devices │
│ │ may be considerably less than on │
│ │ the preferred devices. │
└───────────────────────────────────┴──────────────────────────────────┘
num_entries
The number of cl_device_id entries that can be added to devices. If devices is not
NULL, the num_entries must be greater than zero.
devices
Returns a list of OpenCL devices found. The cl_device_id values returned in devices
can be used to identify a specific OpenCL device. If devices is NULL, this argument is
ignored. The number of OpenCL devices returned is the mininum of the value specified
by num_entries and the number of OpenCL devices corresponding to d3d_object.
num_devices
Returns the number of OpenCL devices available that correspond to d3d_object. If
num_devices is NULL, this argument is ignored.
DESCRIPTION
The OpenCL devices corresponding to a Direct3D 11 device may be queried. The OpenCL
devices corresponding to a DXGI adapter may also be queried. The OpenCL devices
corresponding to a Direct3D 11 device will be a subset of the OpenCL devices corresponding
to the DXGI adapter against which the Direct3D 11 device was created.
NOTES
General information about sharing memory objects with Direct3D 11 follows.
The goal of this extension is to provide interoperability between OpenCL and Direct3D 11.
This is designed to function analogously to the OpenGL interoperability. If this extension
is supported by an implementation, the string cl_khr_d3d11_sharing(3clc) will be present
in the CL_PLATFORM_EXTENSIONS or CL_DEVICE_EXTENSIONS string described in the table of
allowed values for param_name for clGetDeviceInfo(3clc).
As currently proposed the interfaces for this extension would be provided in cl_d3d11.h.
This section discusses OpenCL functions that allow applications to use Direct3D 11
resources as OpenCL memory objects. This allows efficient sharing of data between OpenCL
and Direct3D 11. The OpenCL API may be used to execute kernels that read and/or write
memory objects that are also Direct3D 11 resources. An OpenCL image object may be created
from a Direct3D 11 texture resource. An OpenCL buffer object may be created from a
Direct3D 11 buffer resource. OpenCL memory objects may be created from Direct3D 11 objects
if and only if the OpenCL context has been created from a Direct3D 11 device.
An OpenCL memory object created from a Direct3D 11 resource remains valid as long as the
corresponding Direct3D 11 resource has not been deleted. If the Direct3D 11 resource is
deleted through the Direct3D 11 API, subsequent use of the OpenCL memory object will
result in undefined behavior, including but not limited to possible OpenCL errors, data
corruption, and program termination.
The successful creation of a cl_context against a Direct3D 11 device specified via the
context create parameter CL_CONTEXT_D3D11_DEVICE_KHR will increment the internal Direct3D
reference count on the specified Direct3D 11 device. The internal Direct3D reference count
on that Direct3D 11 device will be decremented when the OpenCL reference count on the
returned OpenCL context drops to zero.
The OpenCL context and corresponding command-queues are dependent on the existence of the
Direct3D 11 device from which the OpenCL context was created. If the Direct3D 11 device is
deleted through the Direct3D 11 API, subsequent use of the OpenCL context will result in
undefined behavior, including but not limited to possible OpenCL errors, data corruption,
and program termination.
Properties of Direct3D 11 objects may be queried using clGetMemObjectInfo(3clc) and
clGetImageInfo(3clc) with param_nameCL_MEM_D3D11_RESOURCE_KHR and
CL_IMAGE_D3D11_SUBRESOURCE_KHR as described for clGetImageInfo(3clc) and in the
information below about accessing mapped regions of a memory object. Accessing mapped
regions of a memory object.PP This section describes the behavior of OpenCL commands that
access mapped regions of a memory object.
The contents of the region of a memory object and associated memory objects (sub-buffer
objects or 1D image buffer objects that overlap this region) mapped for writing (i.e.
CL_MAP_WRITE or CL_MAP_WRITE_INVALIDATE_REGION is set in map_flags argument to
clEnqueueMapBuffer(3clc) or clEnqueueMapImage(3clc)) are considered to be undefined until
this region is unmapped.
Multiple commands in command-queues can map a region or overlapping regions of a memory
object and associated memory objects (sub-buffer objects or 1D image buffer objects that
overlap this region) for reading (i.e. map_flags = CL_MAP_READ). The contents of the
regions of a memory object mapped for reading can also be read by kernels and other OpenCL
commands (such as clEnqueueCopyBuffer(3clc)) executing on a device(s).
Mapping (and unmapping) overlapped regions in a memory object and/or associated memory
objects (sub-buffer objects or 1D image buffer objects that overlap this region) for
writing is an error and will result in CL_INVALID_OPERATION error returned by
clEnqueueMapBuffer(3clc) or clEnqueueMapImage(3clc).
If a memory object is currently mapped for writing, the application must ensure that the
memory object is unmapped before any enqueued kernels or commands that read from or write
to this memory object or any of its associated memory objects (sub-buffer or 1D image
buffer objects) or its parent object (if the memory object is a sub-buffer or 1D image
buffer object) begin execution; otherwise the behavior is undefined.
If a memory object is currently mapped for reading, the application must ensure that the
memory object is unmapped before any enqueued kernels or commands that write to this
memory object or any of its associated memory objects (sub-buffer or 1D image buffer
objects) or its parent object (if the memory object is a sub-buffer or 1D image buffer
object) begin execution; otherwise the behavior is undefined.
Accessing the contents of the memory region referred to by the mapped pointer that has
been unmapped is undefined.
The mapped pointer returned by clEnqueueMapBuffer(3clc) or clEnqueueMapImage(3clc) can be
used as ptr argument value to clEnqueueReadBuffer(3clc), clEnqueueWriteBuffer(3clc),
clEnqueueReadBufferRect(3clc), clEnqueueWriteBufferRect(3clc), clEnqueueReadImage(3clc),
and clEnqueueWriteImage(3clc), provided the rules described above are adhered to.
ERRORS
Returns CL_SUCCESS if the function is executed successfully. Otherwise it may return:
· CL_INVALID_PLATFORM if platform is not a valid platform.
· CL_INVALID_VALUE if d3d_device_source is not a valid value, d3d_device_set is not a
valid value, num_entries is equal to zero and devices is not NULL, or if both
num_devices and devices are NULL.
· CL_DEVICE_NOT_FOUND if no OpenCL devices that correspond to d3d_object were found.
SPECIFICATION
OpenCL Specification[1]
SEE ALSO
cl_khr_d3d11_sharing(3clc), clCreateFromD3D11BufferKHR(3clc),
clCreateFromD3D11Texture2DKHR(3clc), clCreateFromD3D11Texture3DKHR(3clc),
clEnqueueAcquireD3D11ObjectsKHR(3clc), clEnqueueReleaseD3D11ObjectsKHR(3clc)
AUTHORS
The Khronos Group
COPYRIGHT
Copyright © 2007-2011 The Khronos Group Inc.
Permission is hereby granted, free of charge, to any person obtaining a copy of this
software and/or associated documentation files (the "Materials"), to deal in the Materials
without restriction, including without limitation the rights to use, copy, modify, merge,
publish, distribute, sublicense, and/or sell copies of the Materials, and to permit
persons to whom the Materials are furnished to do so, subject to the condition that this
copyright notice and permission notice shall be included in all copies or substantial
portions of the Materials.
NOTES
1. OpenCL Specification
page 102, section 9.11.7.1 - Querying OpenCL Devices Corresponding to Direct3D