NAME

       clEnqueueAcquireD3D11ObjectsKHR - Acquire OpenCL memory objects that have been created
       from Direct3D 11 resources

       cl_int clEnqueueAcquireD3D11ObjectsKHR(cl_command_queue command_queue,
                                              cl_uint num_objects, const cl_mem *mem_objects,
                                              cl_uint num_events_in_wait_list,
                                              const cl_event *event_wait_list, cl_event *event);

PARAMETERS

       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.

NOTES

       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(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 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:

       ·   CL_INVALID_VALUE if num_objects is zero and mem_objects is not a NULL value or if
           num_objects > 0 and mem_objects is NULL.

       ·   CL_INVALID_MEM_OBJECT if memory objects in mem_objects are not valid OpenCL memory
           objects or if memory objects in mem_objects have not been created from Direct3D 11
           resources.

       ·   CL_INVALID_COMMAND_QUEUE if command_queue is not a valid command-queue.

       ·   CL_INVALID_CONTEXT if context associated with command_queue was not created from a
           Direct3D 11 context.

       ·   CL_D3D11_RESOURCE_ALREADY_ACQUIRED_KHR if memory objects in mem_objects have
           previously been acquired using clEnqueueAcquireD3D11ObjectsKHR but have not been
           released using clEnqueueReleaseD3D11ObjectsKHR(3clc).

       ·   CL_D3D11_RESOURCE_ALREADY_ACQUIRED_KHR when any of mem_objectsare currently acquired
           by OpenCL.

       ·   CL_INVALID_EVENT_WAIT_LIST if 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_OUT_OF_HOST_MEMORY if there is a failure to allocate resources required by the
           OpenCL implementation on the host.

SPECIFICATION

       OpenCL Specification[1]

SEE ALSO

       cl_khr_d3d11_sharing(3clc), clGetDeviceIDsFromD3D11KHR(3clc),
       clCreateFromD3D11BufferKHR(3clc), clCreateFromD3D11Texture2DKHR(3clc),
       clCreateFromD3D11Texture3DKHR(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 108, section 9.11.7.6 - Sharing memory objects created from Direct3D 11...