CLGETDEVICEIDSFROMD3(3clc)

📦
version 1.0~svn33624 · 3 versions
, in ubuntu jammy, ubuntu noble

💖 CLGETDEVICEIDSFROMD3 — the 3clc glow-up 💖

okay bestie, sit DOWN, because this one is literally about asking OpenCL "hey which of ur devices vibe with my Direct3D 11 stuff?" and it's from the OpenCL Manual section, 3clc. yes it's a whole quest. but we're doing it together 🫶

✨ NAME ✨

clGetDeviceIDsFromD3D11KHR — Querying OpenCL Devices Corresponding to Direct3D 11 Devices.

no cap, that's the whole plot. you pass in a D3D11 thing, you get back the OpenCL devices that match it. iconic behaviour honestly.

🎀 SYNOPSIS 🎀

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);

seven arguments. seven. she's high maintenance but she delivers 💅

🌸 PARAMETERS 🌸

  • platform — this is the platform ID you got back from clGetPlatformIDs(3clc). it's giving "which OpenCL platform are we even talking to rn".
  • d3d_device_source — tells us what kind of thing d3d_object actually is. it may be one of these two, and yes you must pick correctly or chaos:
    • CL_D3D11_DEVICE_KHR — meaning the type of d3d_object is ID3D11Device *
    • CL_D3D11_DXGI_ADAPTER_KHR — meaning the type of d3d_object is IDXGIAdapter *
  • d3d_object — the actual object whose corresponding OpenCL devices we're out here querying. and bestie, the type of d3d_object must be as specified in the table above. no mixing, no matching, no "close enough". the type has to line up exactly. 😤
  • d3d_device_set — which set of devices you want returned. must be one of these two:
    • CL_PREFERRED_DEVICES_FOR_D3D11_KHR — the OpenCL devices associated with the specified Direct3D object. these are the ones returned in devices.
    • CL_ALL_DEVICES_FOR_D3D11_KHR — all OpenCL devices which may interoperate with the specified Direct3D object. ⚠️ heads up though: performance of sharing data on these devices may be considerably less than on the preferred devices. so like, they'll work, but they're not the main characters.
  • num_entries — the number of cl_device_id entries that can be added to devices. if devices is not NULL, num_entries must be greater than zero. (zero + non-NULL devices = not the vibe.)
  • devices — returns a list of the 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 just ignored, no hard feelings. and 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 too. everybody's so chill.

🦋 DESCRIPTION 🦋

so here's the tea: the OpenCL devices corresponding to a Direct3D 11 device may be queried. the OpenCL devices corresponding to a DXGI adapter may also be queried. and here's the cute little hierarchy moment — 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. nesting dolls. matryoshka. you get it 🪆

💜 NOTES 💜

okay this is the long one, general information about sharing memory objects with Direct3D 11. hydrate, we're going in.

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. 💀 like, actually 💀

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. refcount girlies stay winning 🫶

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. no take-backsies, bestie.

Properties of Direct3D 11 objects may be queried using clGetMemObjectInfo(3clc) and clGetImageInfo(3clc) with param_name CL_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. 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. so like... don't look at it. it's not ready. 🙈

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). yeah no, we don't do that here.
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 pointer is gone. let her rest. 🪦

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. read the rules. the rules. 📜

🔥 ERRORS 🔥

Returns CL_SUCCESS if the function is executed successfully. Otherwise it may return:

  • CL_INVALID_PLATFORM if platform is not a valid platform. (girl, who even are you)
  • 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. 😭 she looked. she found nothing.

⭐ SPECIFICATION ⭐

OpenCL Specification[1]

🌈 SEE ALSO 🌈

cl_khr_d3d11_sharing(3clc), clCreateFromD3D11BufferKHR(3clc), clCreateFromD3D11Texture2DKHR(3clc), clCreateFromD3D11Texture3DKHR(3clc), clEnqueueAcquireD3D11ObjectsKHR(3clc), clEnqueueReleaseD3D11ObjectsKHR(3clc)

the whole friend group, fr fr.

👑 AUTHORS 👑

The Khronos Group

✨ and that's part 1, bestie — hold on, there's more ✨

Copyright © 2007-2011 The Khronos Group Inc.

Okay so bestie, here's the legal bit and it's actually very chill of them. 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 — and yes that includes, without limitation, the rights to:

  • use them 💅
  • copy them 📋
  • modify them ✨
  • merge them 🫶
  • publish them 📢
  • distribute them 🌈
  • sublicense them 🔁
  • and/or sell copies of the Materials 💸

...and to permit persons to whom the Materials are furnished to do so too. Slay, everyone's invited.

But the one condition — the vibe check you cannot fail: the copyright notice above and this permission notice have to be included in all copies or substantial portions of the Materials. Periodt. 🎀

📝 NOTES 📝

  1. OpenCL Specification, page 102, section 9.11.7.1 — Querying OpenCL Devices Corresponding to Direct3D

And that's the whole page, bestie — you made it to the end of the manual and you ate. 👑 This one's from The Khronos Group, dated 01/14/2021, and it lives in the wild as CLGETDEVICEIDSFROMD3(3clc). Go forth and query those devices. 🦋✨

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