.. _reference-doc: OpenCL Platform/Runtime Documentation ===================================== Version Queries --------------- .. module:: pyopencl .. moduleauthor:: Andreas Kloeckner .. data:: VERSION Gives the numeric version of PyOpenCL as a variable-length tuple of integers. Enables easy version checks such as *VERSION >= (0, 93)*. .. data:: VERSION_STATUS A text string such as `"rc4"` or `"beta"` qualifying the status of the release. .. data:: VERSION_TEXT The full release name (such as `"0.93rc4"`) in string form. .. function:: get_cl_header_version() Return a variable-length tuple of integers representing the version of the OpenCL header against which PyOpenCL was compiled. .. versionadded:: 0.92 .. _errors: Error Reporting --------------- .. class:: Error Base class for all PyOpenCL exceptions. .. class:: MemoryError .. class:: LogicError .. class:: RuntimeError Constants --------- .. include:: constants.inc Platforms, Devices and Contexts ------------------------------- .. |comparable| replace:: Instances of this class are hashable, and two instances of this class may be compared using *"=="* and *"!="*. (Hashability was added in version 2011.2.) .. |buf-iface| replace:: must implement the Python buffer interface. (e.g. by being an :class:`numpy.ndarray`) .. |explain-waitfor| replace:: *wait_for* may either be *None* or a list of :class:`Event` instances for whose completion this command waits before starting exeuction. .. |std-enqueue-blurb| replace:: Returns a new :class:`Event`. |explain-waitfor| .. |copy-depr| replace:: **Note:** This function is deprecated as of PyOpenCL 2011.1. Use :func:`enqueue_copy` instead. .. function:: get_platforms() Return a list of :class:`Platform` instances. .. class:: Platform .. attribute:: info Lower case versions of the :class:`platform_info` constants may be used as attributes on instances of this class to directly query info attributes. .. method:: get_info(param) See :class:`platform_info` for values of *param*. .. method:: get_devices(device_type=device_type.ALL) Return a list of devices matching *device_type*. See :class:`device_type` for values of *device_type*. |comparable| .. class:: Device .. attribute:: info Lower case versions of the :class:`device_info` constants may be used as attributes on instances of this class to directly query info attributes. .. method:: get_info(param) See :class:`device_info` for values of *param*. Two instances of this class may be compared using *=="* and *"!="*. .. class:: Context(devices=None, properties=None, dev_type=None) Create a new context. *properties* is a list of key-value tuples, where each key must be one of :class:`context_properties`. At most one of *devices* and *dev_type* may be not `None`, where *devices* is a list of :class:`Device` instances, and *dev_type* is one of the :class:`device_type` constants. If neither is specified, a context with a *dev_type* of :attr:`device_type.DEFAULT` is created. .. note:: Calling the constructor with no arguments will fail for recent CL drivers that support the OpenCL ICD. If you want similar, just-give-me-a-context-already behavior, we recommend :func:`create_some_context`. See, e.g. this `explanation by AMD `_. .. note:: For :attr:`context_properties.CL_GL_CONTEXT_KHR`, :attr:`context_properties.CL_EGL_DISPLAY_KHR`, :attr:`context_properties.CL_GLX_DISPLAY_KHR`, :attr:`context_properties.CL_WGL_HDC_KHR`, and :attr:`context_properties.CL_CGL_SHAREGROUP_KHR` :attr:`context_properties.CL_CGL_SHAREGROUP_APPLE` the value in the key-value pair is a PyOpenGL context or display instance. .. versionchanged:: 0.91.2 Constructor arguments *dev_type* added. .. attribute:: info Lower case versions of the :class:`context_info` constants may be used as attributes on instances of this class to directly query info attributes. .. method:: get_info(param) See :class:`context_info` for values of *param*. .. method:: create_sub_devices(properties) *properties* is an array of one (or more) of the forms:: [ dpp.EQUALLY, 8] [ dpp.BY_COUNTS, 5, 7, 9, dpp.PARTITION_BY_COUNTS_LIST_END] [ dpp.BY_NAMES, 5, 7, 9, dpp.PARTITION_BY_NAMES_LIST_END] [ dpp.BY_AFFINITY_DOMAIN, dad.L1_CACHE] where `dpp` represents :class:`device_partition_property` and `dad` represent :class:`device_affinity_domain`. `PROPERTIES_LIST_END_EXT` is added automatically. Only available with CL 1.2. .. versionadded:: 2011.2 .. method:: create_sub_devices_ext(properties) *properties* is an array of one (or more) of the forms:: [ dppe.EQUALLY, 8] [ dppe.BY_COUNTS, 5, 7, 9, dppe.PARTITION_BY_COUNTS_LIST_END] [ dppe.BY_NAMES, 5, 7, 9, dppe.PARTITION_BY_NAMES_LIST_END] [ dppe.BY_AFFINITY_DOMAIN, ad.L1_CACHE] where `dppe` represents :class:`device_partition_property_ext` and `ad` represent :class:`affinity_domain_ext`. `PROPERTIES_LIST_END_EXT` is added automatically. Only available with the `cl_ext_device_fission` extension. .. versionadded:: 2011.1 |comparable| .. function:: create_some_context(interactive=True) Create a :class:`Context` 'somehow'. If multiple choices for platform and/or device exist, *interactive* is True, and *sys.stdin.isatty()* is also True, then the user is queried about which device should be chosen. Otherwise, a device is chosen in an implementation-defined manner. Command Queues and Events ------------------------- .. class:: CommandQueue(context, device=None, properties=None) Create a new command queue. *properties* is a bit field consisting of :class:`command_queue_properties` values. if *device* is None, one of the devices in *context* is chosen in an implementation-defined manner. .. attribute:: info Lower case versions of the :class:`command_queue_info` constants may be used as attributes on instances of this class to directly query info attributes. .. method:: get_info(param) See :class:`command_queue_info` for values of *param*. .. method:: set_property(prop, enable) See :class:`command_queue_properties` for possible values of *prop*. *enable* is a :class:`bool`. Unavailable in OpenCL 1.1 and newer. .. method:: flush() .. method:: finish() |comparable| .. class:: Event .. attribute:: info Lower case versions of the :class:`event_info` constants may be used as attributes on instances of this class to directly query info attributes. .. attribute:: profile.info Lower case versions of the :class:`profiling_info` constants may be used as attributes on the attribute `profile` of this class to directly query profiling info. For example, you may use *evt.profile.end* instead of *evt.get_profiling_info(pyopencl.profiling_info.END)*. .. method:: get_info(param) See :class:`event_info` for values of *param*. .. method:: get_profiling_info(param) See :class:`profiling_info` for values of *param*. See :attr:`profile` for an easier way of obtaining the same information. .. method:: wait() |comparable| .. function:: wait_for_events(events) .. function:: enqueue_barrier(queue, wait_for=None) Enqueues a barrier operation. which ensures that all queued commands in command_queue have finished execution. This command is a synchronization point. .. versionadded:: 0.91.5 .. versionchanged:: 2011.2 Takes *wait_for* and returns an :class:`Event` .. function:: enqueue_marker(queue, wait_for=None) Returns an :class:`Event`. .. versionchanged:: 2011.2 Takes *wait_for*. .. function:: enqueue_wait_for_events(queue, events) **Note:** This function is deprecated as of PyOpenCL 2011.2. Use :func:`enqueue_marker` instead. .. class:: UserEvent(context) A subclass of :class:`Event`. Only available with OpenCL 1.1 and newer. .. versionadded:: 0.92 .. method:: set_status(status) See :class:`command_execution_status` for possible values of *status*. .. class:: NannyEvent Transfers between host and device return events of this type. They hold a reference to the host-side buffer and wait for the transfer to complete when they are freed. Therefore, they can safely release the reference to the object they're guarding upon destruction. A subclass of :class:`Event`. .. versionadded:: 2011.2 .. method:: get_ward() .. method:: wait() In addition to performing the same wait as :meth:`Event.wait()`, this method also releases the reference to the guarded object. Memory ------ .. class:: MemoryObject .. attribute:: info Lower case versions of the :class:`mem_info` constants may be used as attributes on instances of this class to directly query info attributes. .. attribute:: hostbuf .. method:: get_info(param) See :class:`mem_info` for values of *param*. .. method:: release() .. method:: get_host_array(shape, dtype, order="C") Return the memory object's associated host memory area as a :class:`numpy.ndarray` of the given *shape*, *dtype* and *order*. |comparable| .. function:: enqueue_migrate_mem_objects(queue, mem_objects, flags=0, wait_for=None) :param flags: from :class:`mem_migration_flags` .. versionadded:: 2011.2 Only available with CL 1.2. .. function:: enqueue_migrate_mem_object_ext(queue, mem_objects, flags=0, wait_for=None) :param flags: from :class:`migrate_mem_object_flags_ext` .. versionadded:: 2011.2 Only available with the `cl_ext_migrate_memobject` extension. Buffers ^^^^^^^ .. class:: Buffer(context, flags, size=0, hostbuf=None) Create a :class:`Buffer`. See :class:`mem_flags` for values of *flags*. If *hostbuf* is specified, *size* defaults to the size of the specified buffer if it is passed as zero. :class:`Buffer` is a subclass of :class:`MemoryObject`. Note that actual memory allocation in OpenCL may be deferred. Buffers are attached to a :class:`Context` and are only moved to a device once the buffer is used on that device. That is also the point when out-of-memory errors will occur. If you'd like to be sure that there's enough memory for your allocation, either use :func:`enqueue_migrate_mem_objects` (if available) or simply perform a small transfer to the buffer. See also :class:`pyopencl.tools.ImmediateAllocator`. .. method:: get_sub_region(origin, size, flags=0) Only available in OpenCL 1.1 and newer. .. method:: __getitem__(slc) *slc* is a :class:`slice` object indicating from which byte index range a sub-buffer is to be created. The *flags* argument of :meth:`get_sub_region` is set to the same flags with which *self* was created. .. function:: enqueue_fill_buffer(queue, mem, pattern, offset, size, wait_for=None) :arg pattern: a buffer object (likely a :class:`numpy.ndarray`) |std-enqueue-blurb| Only available with CL 1.2. .. versionadded:: 2011.2 Image Formats ^^^^^^^^^^^^^ .. class:: ImageFormat([channel_order, channel_type]) .. versionchanged:: 0.91 Constructor arguments added. .. attribute:: channel_order See :class:`channel_order` for possible values. .. attribute:: channel_data_type See :class:`channel_type` for possible values. .. attribute:: channel_count .. versionadded:: 0.91.5 .. attribute:: dtype_size .. versionadded:: 0.91.5 .. attribute:: itemsize .. versionadded:: 0.91.5 .. method:: __repr__ Returns a :class:`str` representation of the image format. .. versionadded:: 0.91 .. function:: get_supported_image_formats(context, flags, image_type) See :class:`mem_flags` for possible values of *flags* and :class:`mem_object_type` for possible values of *image_type*. Images ^^^^^^ .. class:: Image(context, flags, format, shape=None, pitches=None, hostbuf=None, is_array=False, buffer=None): See :class:`mem_flags` for values of *flags*. *shape* is a 2- or 3-tuple. *format* is an instance of :class:`ImageFormat`. *pitches* is a 1-tuple for 2D images and a 2-tuple for 3D images, indicating the distance in bytes from one scan line to the next, and from one 2D image slice to the next. If *hostbuf* is given and *shape* is `None`, then *hostbuf.shape* is used as the *shape* parameter. :class:`Image` is a subclass of :class:`MemoryObject`. .. note:: If you want to load images from :mod:`numpy.ndarray` instances or read images back into them, be aware that OpenCL images expect the *x* dimension to vary fastest, whereas in the default (C) order of :mod:`numpy` arrays, the last index varies fastest. If your array is arranged in the wrong order in memory, there are two possible fixes for this: * Convert the array to Fortran (column-major) order using :func:`numpy.asarray`. * Pass *ary.T.copy()* to the image creation function. .. versionadded:: 0.91 .. versionchanged:: 2011.2 Added *is_array* and *buffer*, which are only available on CL 1.2 and newer. .. attribute:: info Lower case versions of the :class:`mem_info` and :class:`image_info` constants may be used as attributes on instances of this class to directly query info attributes. .. attribute:: shape Return the value of the *shape* constructor argument as a :class:`tuple`. .. method:: get_image_info(param) See :class:`image_info` for values of *param*. .. method:: release() |comparable| .. function:: image_from_array(ctx, ary, num_channels=None, mode="r", norm_int=False) Build a 2D or 3D :class:`Image` from the :class:`numpy.ndarray` *ary*. If *num_channels* is greater than one, the last dimension of *ary* must be identical to *num_channels*. *ary* must be in C order. If *num_channels* is not given, it defaults to 1 for scalar types and the number of entries for :ref:`vector-types`. The :class:`ImageFormat` is chosen as the first *num_channels* components of "RGBA". :param mode: "r" or "w" for read/write .. note:: When reading from the image object, the indices passed to `read_imagef` are in the reverse order from what they would be when accessing *ary* from Python. If *norm_int* is `True`, then the integer values are normalized to a floating point scale of 0..1 when read. .. versionadded:: 2011.2 .. function:: enqueue_fill_image(queue, mem, color, origin, region, wait_for=None) :arg color: a buffer object (likely a :class:`numpy.ndarray`) |std-enqueue-blurb| Only available with CL 1.2. .. versionadded:: 2011.2 Transfers ^^^^^^^^^ .. function:: enqueue_copy(queue, dest, src, **kwargs) Copy from :class:`Image`, :class:`Buffer` or the host to :class:`Image`, :class:`Buffer` or the host. (Note: host-to-host copies are unsupported.) The following keyword arguments are available: :arg wait_for: (optional, default empty) :arg is_blocking: Wait for completion. Defaults to *True*. (Available on any copy involving host memory) :return: A :class:`NannyEvent` if the transfer involved a host-side buffer, otherwise an :class:`Event`. :class:`Buffer` ↔ host transfers: :arg device_offset: offset in bytes (optional) :class:`Buffer` ↔ :class:`Buffer` transfers: :arg byte_count: (optional) :arg src_offset: (optional) :arg dest_offset: (optional) Rectangular :class:`Buffer` ↔ host transfers (CL 1.1 and newer): :arg buffer_origin: :class:`tuple` of :class:`int` of length three or shorter. (mandatory) :arg host_origin: :class:`tuple` of :class:`int` of length three or shorter. (mandatory) :arg region: :class:`tuple` of :class:`int` of length three or shorter. (mandatory) :arg buffer_pitches: :class:`tuple` of :class:`int` of length two or shorter. (optional, "tightly-packed" if unspecified) :arg host_pitches: :class:`tuple` of :class:`int` of length two or shorter. (optional, "tightly-packed" if unspecified) :class:`Image` ↔ host transfers: :arg origin: :class:`tuple` of :class:`int` of length three or shorter. (mandatory) :arg region: :class:`tuple` of :class:`int` of length three or shorter. (mandatory) :arg pitches: :class:`tuple` of :class:`int` of length two or shorter. (optional) :class:`Buffer` ↔ :class:`Image` transfers: :arg offset: offset in buffer (mandatory) :arg origin: :class:`tuple` of :class:`int` of length three or shorter. (mandatory) :arg region: :class:`tuple` of :class:`int` of length three or shorter. (mandatory) :class:`Image` ↔ :class:`Image` transfers: :arg src_origin: :class:`tuple` of :class:`int` of length three or shorter. (mandatory) :arg dest_origin: :class:`tuple` of :class:`int` of length three or shorter. (mandatory) :arg region: :class:`tuple` of :class:`int` of length three or shorter. (mandatory) |std-enqueue-blurb| .. versionadded:: 2011.1 Mapping Memory into Host Address Space ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ .. class:: MemoryMap .. method:: release(queue=None, wait_for=None) .. function:: enqueue_map_buffer(queue, buf, flags, offset, shape, dtype, order="C", wait_for=None, is_blocking=True) |explain-waitfor| *shape*, *dtype*, and *order* have the same meaning as in :func:`numpy.empty`. See :class:`map_flags` for possible values of *flags*. :return: a tuple *(array, event)*. *array* is a :class:`numpy.ndarray` representing the host side of the map. Its *.base* member contains a :class:`MemoryMap`. .. versionchanged:: 2011.1 *is_blocking* now defaults to True. .. versionchanged:: 2012.2 *order* now defaults to "C". .. function:: enqueue_map_image(queue, buf, flags, origin, region, shape, dtype, order="C", wait_for=None, is_blocking=True) |explain-waitfor| *shape*, *dtype*, and *order* have the same meaning as in :func:`numpy.empty`. See :class:`map_flags` for possible values of *flags*. :return: a tuple *(array, event)*. *array* is a :class:`numpy.ndarray` representing the host side of the map. Its *.base* member contains a :class:`MemoryMap`. .. versionchanged:: 2011.1 *is_blocking* now defaults to True. .. versionchanged:: 2012.2 *order* now defaults to "C". Samplers ^^^^^^^^ .. class:: Sampler(context, normalized_coords, addressing_mode, filter_mode) *normalized_coords* is a :class:`bool` indicating whether to use coordinates between 0 and 1 (*True*) or the texture's natural pixel size (*False*). See :class:`addressing_mode` and :class:`filter_mode` for possible argument values. .. attribute:: info Lower case versions of the :class:`sampler_info` constants may be used as attributes on instances of this class to directly query info attributes. .. method:: get_info(param) See :class:`sampler_info` for values of *param*. |comparable| Programs and Kernels -------------------- .. class:: Program(context, src) Program(context, devices, binaries) *binaries* must contain one binary for each entry in *devices*. .. attribute:: info Lower case versions of the :class:`program_info` constants may be used as attributes on instances of this class to directly query info attributes. .. method:: get_info(param) See :class:`program_info` for values of *param*. .. method:: get_build_info(device, param) See :class:`program_build_info` for values of *param*. .. method:: build(options=[], devices=None) *options* is a string of compiler flags. Returns *self*. By default, built binaries are cached in an on-disk cache called :file:`pyopencl-compiler-cache-vN-uidNAME-pyVERSION` in the directory returned by :func:`tempfile.gettempdir`. By setting the environment variable :envvar:`PYOPENCL_NO_CACHE` to any non-empty value, this caching is suppressed. .. versionchanged:: 2011.1 *options* may now also be a :class:`list` of :class:`str`. .. versionchanged:: 2012.2 Added :envvar:`PYOPENCL_NO_CACHE`. .. method:: compile(self, options=[], devices=None, headers=[]) :param headers: a list of tuples *(name, program)*. Only available with CL 1.2. .. versionadded:: 2011.2 .. attribute:: kernel_name :class:`Kernel` objects can be produced from a built (see :meth:`build`) program simply by attribute lookup. .. note:: The :class:`program_info` attributes live in the same name space and take precedence over :class:`Kernel` names. |comparable| .. method:: all_kernels() Returns a list of all :class:`Kernel` objects in the :class:`Program`. .. function:: create_program_with_built_in_kernels(context, devices, kernel_names) Only available with CL 1.2. .. versionadded:: 2011.2 .. function:: link_program(context, programs, options=[], devices=None) Only available with CL 1.2. .. versionadded:: 2011.2 .. function:: unload_platform_compiler(platform) Only available with CL 1.2. .. versionadded:: 2011.2 .. class:: Kernel(program, name) .. attribute:: info Lower case versions of the :class:`kernel_info` constants may be used as attributes on instances of this class to directly query info attributes. .. method:: get_info(param) See :class:`kernel_info` for values of *param*. .. method:: get_work_group_info(param, device) See :class:`kernel_work_group_info` for values of *param*. .. method:: get_arg_info(arg_index, param) See :class:`kernel_arg_info` for values of *param*. Only available in OpenCL 1.2 and newer. .. method:: set_arg(self, index, arg) *arg* may be * `None`: This may be passed for `__global` memory references to pass a NULL pointer to the kernel. * Anything that satisfies the Python buffer interface, in particular :class:`numpy.ndarray`, :class:`str`, or :mod:`numpy`'s sized scalars, such as :class:`numpy.int32` or :class:`numpy.float64`. .. note:: Note that Python's own :class:`int` or :class:`float` objects will not work out of the box. See :meth:`Kernel.set_scalar_arg_dtypes` for a way to make them work. Alternatively, the standard library module :mod:`struct` can be used to convert Python's native number types to binary data in a :class:`str`. * An instance of :class:`MemoryObject`. (e.g. :class:`Buffer`, :class:`Image`, etc.) * An instance of :class:`LocalMemory`. * An instance of :class:`Sampler`. .. method:: set_args(self, *args) Invoke :meth:`set_arg` on each element of *args* in turn. .. versionadded:: 0.92 .. method:: set_scalar_arg_dtypes(arg_dtypes) Inform the wrapper about the sized types of scalar :class:`Kernel` arguments. For each argument, *arg_dtypes* contains an entry. For non-scalars, this must be *None*. For scalars, it must be an object acceptable to the :class:`numpy.dtype` constructor, indicating that the corresponding scalar argument is of that type. After invoking this function with the proper information, most suitable number types will automatically be cast to the right type for kernel invocation. .. note :: The information set by this rountine is attached to a single kernel instance. A new kernel instance is created every time you use `program.kernel` attribute access. The following will therefore not work:: prg = cl.Program(...).build() prg.kernel.set_scalar_arg_dtypes(...) prg.kernel(queue, n_globals, None, args) .. method:: __call__(queue, global_size, local_size, *args, global_offset=None, wait_for=None, g_times_l=False) Use :func:`enqueue_nd_range_kernel` to enqueue a kernel execution, after using :meth:`set_args` to set each argument in turn. See the documentation for :meth:`set_arg` to see what argument types are allowed. |std-enqueue-blurb| *None* may be passed for local_size. If *g_times_l* is specified, the global size will be multiplied by the local size. (which makes the behavior more like Nvidia CUDA) In this case, *global_size* and *local_size* also do not have to have the same number of dimensions. .. note:: :meth:`__call__` is *not* thread-safe. It sets the arguments using :meth:`set_args` and then runs :func:`enqueue_nd_range_kernel`. Another thread could race it in doing the same things, with undefined outcome. This issue is inherited from the C-level OpenCL API. The recommended solution is to make a kernel (i.e. access `prg.kernel_name`, which corresponds to making a new kernel) for every thread that may enqueue calls to the kernel. A solution involving implicit locks was discussed and decided against on the mailing list in `October 2012 `_. .. versionchanged:: 0.92 *local_size* was promoted to third positional argument from being a keyword argument. The old keyword argument usage will continue to be accepted with a warning throughout the 0.92 release cycle. This is a backward-compatible change (just barely!) because *local_size* as third positional argument can only be a :class:`tuple` or *None*. :class:`tuple` instances are never valid :class:`Kernel` arguments, and *None* is valid as an argument, but its treatment in the wrapper had a bug (now fixed) that prevented it from working. .. versionchanged:: 2011.1 Added the *g_times_l* keyword arg. |comparable| .. class:: LocalMemory(size) A helper class to pass `__local` memory arguments to kernels. .. versionadded:: 0.91.2 .. attribute:: size The size of local buffer in bytes to be provided. .. function:: enqueue_nd_range_kernel(queue, kernel, global_work_size, local_work_size, global_work_offset=None, wait_for=None, g_times_l=True) |std-enqueue-blurb| If *g_times_l* is specified, the global size will be multiplied by the local size. (which makes the behavior more like Nvidia CUDA) In this case, *global_size* and *local_size* also do not have to have the same number of dimensions. .. versionchanged:: 2011.1 Added the *g_times_l* keyword arg. .. function:: enqueue_task(queue, kernel, wait_for=None) |std-enqueue-blurb| .. _gl-interop: GL Interoperability ------------------- Functionality in this section is only available when PyOpenCL is compiled with GL support. See :func:`have_gl`. .. versionadded:: 0.91 .. function:: have_gl() Return *True* if PyOpenCL was compiled with OpenGL interoperability, otherwise *False*. .. function:: get_gl_sharing_context_properties() Return a :class:`list` of :class:`context_properties` that will allow a newly created context to share the currently active GL context. .. function:: get_apple_cgl_share_group() Get share group handle for current CGL context. Apple OS X only. .. versionadded:: 2011.1 .. class:: GLBuffer(context, flags, bufobj) :class:`GLBuffer` is a subclass of :class:`MemoryObject`. .. attribute:: gl_object .. class:: GLRenderBuffer(context, flags, bufobj) :class:`GLRenderBuffer` is a subclass of :class:`MemoryObject`. .. attribute:: gl_object .. class:: GLTexture(context, flags, texture_target, miplevel, texture, dims) *dims* is either 2 or 3. :class:`GLTexture` is a subclass of :class:`Image`. .. attribute:: gl_object .. method:: get_gl_texture_info(param) See :class:`gl_texture_info` for values of *param*. Only available when PyOpenCL is compiled with GL support. See :func:`have_gl`. .. function:: enqueue_acquire_gl_objects(queue, mem_objects, wait_for=None) *mem_objects* is a list of :class:`MemoryObject` instances. |std-enqueue-blurb| .. function:: enqueue_release_gl_objects(queue, mem_objects, wait_for=None) *mem_objects* is a list of :class:`MemoryObject` instances. |std-enqueue-blurb| .. function:: get_gl_context_info_khr(properties, param_name, platform=None) Get information on which CL device corresponds to a given GL/EGL/WGL/CGL device. See the :class:`Context` constructor for the meaning of *properties* and :class:`gl_context_info` for *param_name*. .. versionchanged:: 2011.2 Accepts the *platform* argument. Using *platform* equal to None is deprecated as of PyOpenCL 2011.2.