Provided by: opencl-1.2-man-doc_1.0~svn22836-1.1_all 
NAME
clGetContextInfo - Query information about a context.
cl_int clGetContextInfo(cl_context context, cl_context_info param_name, size_t param_value_size,
void *param_value, size_t *param_value_size_ret);
PARAMETERS
context
Specifies the OpenCL context being queried.
param_name
An enumeration constant that specifies the information to query. The valid values for param_name are:
┌───────────────────────────┬───────────────────────────┬────────────────────────────────┐
│cl_context_info │ Return Type │ Information returned in │
│ │ │ param_value │
├───────────────────────────┼───────────────────────────┼────────────────────────────────┤
│CL_CONTEXT_REFERENCE_COUNT │ cl_uint │ Return the context reference │
│ │ │ count. The reference count │
│ │ │ returned should be │
│ │ │ considered immediately │
│ │ │ stale. It is unsuitable for │
│ │ │ general use in applications. │
│ │ │ This feature is provided for │
│ │ │ identifying memory leaks. │
├───────────────────────────┼───────────────────────────┼────────────────────────────────┤
│CL_CONTEXT_NUM_DEVICES │ cl_uint │ Return the number of devices │
│ │ │ in context. │
├───────────────────────────┼───────────────────────────┼────────────────────────────────┤
│CL_CONTEXT_DEVICES │ cl_device_id[] │ Return the list of devices │
│ │ │ in context. │
├───────────────────────────┼───────────────────────────┼────────────────────────────────┤
│CL_CONTEXT_PROPERTIES │ cl_context_- properties[] │ Return the properties │
│ │ │ argument specified in │
│ │ │ clCreateContext(3clc) or │
│ │ │ clCreateContextFromType(3clc). │
│ │ │ If the properties argument │
│ │ │ specified in │
│ │ │ clCreateContext(3clc) or │
│ │ │ clCreateContextFromType(3clc) │
│ │ │ used to create context is │
│ │ │ not NULL, the implementation │
│ │ │ must return the values │
│ │ │ specified in the properties │
│ │ │ argument. │
│ │ │ │
│ │ │ properties argument │
│ │ │ specified in │
│ │ │ clCreateContext(3clc) or │
│ │ │ clCreateContextFromType(3clc) │
│ │ │ used to create context is │
│ │ │ NULL, the implementation may │
│ │ │ return either a │
│ │ │ param_value_size_ret of 0, │
│ │ │ i.e. there is no context │
│ │ │ property value to be │
│ │ │ returned or can return a │
│ │ │ context property value of 0 │
│ │ │ (where 0 is used to │
│ │ │ terminate the context │
│ │ │ properties list) in the │
│ │ │ memory that param_value │
│ │ │ points to. │
├───────────────────────────┼───────────────────────────┼────────────────────────────────┤
│CL_CONTEXT_D3D10_PREFER_- │ cl_bool │ If the │
│SHARED_RESOURCES_KHR │ │ cl_khr_d3d10_sharing(3clc) │
│ │ │ extension is enabled, returns │
│ │ │ CL_TRUE if Direct3D 10 │
│ │ │ resources created as shared by │
│ │ │ setting MiscFlags to include │
│ │ │ D3D10_RESOURCE_MISC_SHARED │
│ │ │ will perform faster when │
│ │ │ shared with OpenCL, compared │
│ │ │ with resources which have not │
│ │ │ set this flag. Otherwise │
│ │ │ returns CL_FALSE. │
├───────────────────────────┼───────────────────────────┼────────────────────────────────┤
│CL_CONTEXT_D3D11_PREFER_- │ cl_bool │ If the cl_khr_d3d11_sharing │
│SHARED_RESOURCES_KHR │ │ extension is supported, │
│ │ │ Returns CL_TRUE if Direct3D 11 │
│ │ │ resources created as shared by │
│ │ │ setting MiscFlags to include │
│ │ │ D3D11_RESOURCE_MISC_SHARED │
│ │ │ will perform faster when │
│ │ │ shared with OpenCL, compared │
│ │ │ with resources which have not │
│ │ │ set this flag. Otherwise │
│ │ │ returns CL_FALSE. │
└───────────────────────────┴───────────────────────────┴────────────────────────────────┘
param_value
A pointer to memory where the appropriate result being queried is returned. If param_value is NULL,
it is ignored.
param_value_size
Specifies the size in bytes of memory pointed to by param_value. This size must be greater than or
equal to the size of return type as described in the table above.
param_value_size_ret
Returns the actual size in bytes of data being queried by param_value. If param_value_size_ret is
NULL, it is ignored.
ERRORS
Returns CL_SUCCESS if the function executed successfully, or one of the errors below:
• CL_INVALID_CONTEXT if context is not a valid context.
• CL_INVALID_VALUE if param_name is not one of the supported values or if size in bytes specified by
param_value_size is < size of return type as specified in the table above and param_value is not a
NULL value.
• CL_OUT_OF_RESOURCES if there is a failure to allocate resources required by the OpenCL implementation
on the device.
• 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
clGetDeviceInfo(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 58, section 4.4 - Contexts