clGetContextInfo.adoc

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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 or clCreateContextFromType. If the properties argument specified in clCreateContext or clCreateContextFromType used to create context is not NULL, the implementation must return the values specified in the properties argument. If the properties argument specified in clCreateContext or clCreateContextFromType 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_- SHARED_RESOURCES_KHR	cl_bool	If the cl_khr_d3d10_sharing 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_- SHARED_RESOURCES_KHR	cl_bool	If the cl_khr_d3d11_sharing extension is enabled, 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.

Also see

clGetDeviceInfo

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