Provided by: opencl-1.2-man-doc_1.0~svn33624-1_all 
NAME
clGetCommandQueueInfo - Query information about a command-queue.
cl_int clGetCommandQueueInfo(cl_command_queue command_queue,
cl_command_queue_info param_name, size_t param_value_size,
void *param_value, size_t *param_value_size_ret);
PARAMETERS
command_queue
Specifies the command-queue being queried.
param_name
Specifies the information to query.
param_value_size
Specifies the size in bytes of memory pointed to by param_value. This size must be ≥
size of return type as described in the table below. If param_value is NULL, it is
ignored.
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_ret
Returns the actual size in bytes of data being queried by param_value. If
param_value_size_ret is NULL, it is ignored
The list of supported param_name values and the information returned in param_value by
clGetCommandQueueInfo is described in the table below.
┌─────────────────────────┬──────────────────────────────────┐
│cl_command_queue_info │ Return Type and Information │
│ │ returned in param_value │
├─────────────────────────┼──────────────────────────────────┤
│CL_QUEUE_CONTEXT │ Return type: cl_context │
│ │ │
│ │ Return the context specified │
│ │ when the command-queue is │
│ │ created. │
├─────────────────────────┼──────────────────────────────────┤
│CL_QUEUE_DEVICE │ Return type: cl_device_id │
│ │ │
│ │ Return the device specified when │
│ │ the command-queue is created. │
├─────────────────────────┼──────────────────────────────────┤
│CL_QUEUE_REFERENCE_COUNT │ Return type: cl_uint │
│ │ │
│ │ Return the command-queue │
│ │ reference count. │
│ │ │
│ │ CL_QUEUE_REFERENCE_COUNT should │
│ │ be considered immediately stale. │
│ │ It is unsuitable for general use │
│ │ in applications. This feature is │
│ │ provided for identifying memory │
│ │ leaks. │
├─────────────────────────┼──────────────────────────────────┤
│CL_QUEUE_PROPERTIES │ Return type: │
│ │ cl_command_queue_properties │
│ │ │
│ │ Return the currently specified │
│ │ properties for the │
│ │ command-queue. These properties │
│ │ are specified by the properties │
│ │ argument in │
│ │ clCreateCommandQueue(3clc). │
└─────────────────────────┴──────────────────────────────────┘
NOTES
It is possible that a device(s) becomes unavailable after a context and command-queues
that use this device(s) have been created and commands have been queued to command-queues.
In this case the behavior of OpenCL API calls that use this context (and command-queues)
are considered to be implementation-defined. The user callback function, if specified,
when the context is created can be used to record appropriate information in the errinfo,
private_info arguments passed to the callback function when the device becomes
unavailable.
ERRORS
Returns CL_SUCCESS if the function is executed successfully. Otherwise, it returns the
following:
• Returns CL_INVALID_COMMAND_QUEUE if command_queue is not a valid command-queue.
• Returns CL_INVALID_VALUE if param_name is not one of the supported values or if size
in bytes specified by param_value_size is less than size of return type 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
clCreateCommandQueue(3clc), clReleaseCommandQueue(3clc), clRetainCommandQueue(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 63, section 5.1 - Command Queues