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`
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
shape is a 2- or 3-tuple.
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 "!=".

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`.