runtime.rst



OpenCL Platform/Runtime Documentation

Version Queries

Error Reporting
Base class for all PyOpenCL exceptions.

Constants

Platforms, Devices and Contexts
Two instances of this class may be compared
using "==" and "!=".
Two instances of this class may be compared using ==" and "!=".
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.

Two instances of this class may be compared
using "==" and "!=".

Command Queues and Events
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.
Two instances of this class may be compared
using "==" and "!=".
Two instances of this class may be compared
using "==" and "!=".
A subclass of :class:`Event`. Only available with OpenCL 1.1 and newer.

Memory
Two instances of this class may be compared
using "==" and "!=".

Buffers
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`.

Image Formats

Images
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.


Two instances of this class may be compared
using "==" and "!=".

Transfers

Mapping Memory into Host Address Space

Samplers
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.
Two instances of this class may be compared
using "==" and "!=".

Programs and Kernels
binaries must contain one binary for each entry in devices.
Two instances of this class may be compared
using "==" and "!=".
Two instances of this class may be compared
using "==" and "!=".
A helper class to pass __local memory arguments to kernels.

GL Interoperability
Functionality in this section is only available when PyOpenCL is compiled
with GL support. See :func:`have_gl`.
:class:`GLBuffer` is a subclass of :class:`MemoryObject`.
:class:`GLRenderBuffer` is a subclass of :class:`MemoryObject`.
dims is either 2 or 3.
:class:`GLTexture` is a subclass of :class:`Image`.