Acquire OpenCL memory objects that have been created from Direct3D 11 resources
command_queue
A valid command-queue.
num_objects
The number of memory objects to be acquired in mem_objects
.
mem_objects
A pointer to a list of OpenCL memory objects that were created from Direct3D 11 resources.
num_events_in_wait_list
, event_wait_list
Specify events that need to complete before this particular
command can be executed. If event_wait_list
is NULL, then this particular command does not wait on any
event to complete. If event_wait_list
is
NULL, num_events_in_wait_list
must be 0. If
event_wait_list
is not NULL, the list of events
pointed to by event_wait_list
must be valid and
num_events_in_wait_list
must be greater than 0. The events
specified in event_wait_list
act as synchronization points.
event
Returns an event object that identifies this particular command and
can be used to query or queue a wait for this particular command to
complete. event
can be NULL in which case it will not be
possible for the application to query the status of this command or queue a wait
for this command to complete. If the event_wait_list
and the
event
arguments are not NULL, the event
argument should not refer to an element of the event_wait_list
array.
The Direct3D 11 objects are acquired by the OpenCL context associated with
command-queue
and can therefore be used by all command-queues
associated with the OpenCL context.
OpenCL memory objects created from Direct3D 11 resources must be acquired before
they can be used by any OpenCL commands queued to a command-queue. If an OpenCL
memory object created from a Direct3D 11 resource is used while it is not currently
acquired by OpenCL, the call attempting to use that OpenCL memory object will return
CL_D3D11_RESOURCE_NOT_ACQUIRED_KHR
.
If CL_CONTEXT_INTEROP_USER_SYNC
is not
specified as CL_TRUE
during context creation,
clEnqueueAcquireD3D11ObjectsKHR
provides the synchronization
guarantee that any Direct3D 11 calls involving the interop device(s) used in the
OpenCL context made before clEnqueueAcquireD3D11ObjectsKHR
is called will complete executing before event
reports
completion and before the execution of any subsequent OpenCL work issued
in command_queue
begins. If the context was created with
properties specifying CL_CONTEXT_INTEROP_USER_SYNC
as
CL_TRUE
, the user is responsible for guaranteeing that any
Direct3D 11 calls involving the interop device(s) used in the OpenCL context made
before clEnqueueAcquireD3D11ObjectsKHR
is called have completed
before calling clEnqueueAcquireD3D11ObjectsKHR
.
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
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.
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
and clGetImageInfo
with param_name
CL_MEM_D3D11_RESOURCE_KHR
and
CL_IMAGE_D3D11_SUBRESOURCE_KHR
as described for clGetImageInfo and in the information
below about accessing mapped regions of a memory object.
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
or clEnqueueMapImage) 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) 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
or clEnqueueMapImage.
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
or clEnqueueMapImage can be used as
ptr
argument value to
clEnqueueReadBuffer,
clEnqueueWriteBuffer,
clEnqueueReadBufferRect,
clEnqueueWriteBufferRect,
clEnqueueReadImage, and
clEnqueueWriteImage,
provided the rules described above are adhered to.
Returns CL_SUCCESS returns CL_SUCCESS
if the function is executed successfully. If num_objects
is 0 and
mem_objects
is NULL then the function does nothing and returns
CL_SUCCESS. Otherwise it returns one of the following errors:
num_objects
is zero and mem_objects
is not a NULL value or if
num_objects
> 0 and mem_objects
is NULL.
mem_objects
are not valid OpenCL memory objects or if memory
objects in mem_objects
have not been created from Direct3D
11 resources.
command_queue
is not a valid command-queue.
command_queue
was not created from a Direct3D 11 context.
mem_objects
have previously been acquired using
clEnqueueAcquireD3D11ObjectsKHR
but have not been released using
clEnqueueReleaseD3D11ObjectsKHR.
mem_objects
are currently acquired by OpenCL.
event_wait_list
is NULL and
num_event_in_wait_list
> 0,
or event_wait_list
is not NULL and
num_event_in_wait_list
is 0, or if event objects in
event_wait_list
are not valid events.
cl_khr_d3d11_sharing, clGetDeviceIDsFromD3D11KHR, clCreateFromD3D11BufferKHR, clCreateFromD3D11Texture2DKHR, clCreateFromD3D11Texture3DKHR, clEnqueueReleaseD3D11ObjectsKHR