C Specification

To query information about a command-queue, call the function

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 is a pointer to memory where the appropriate result being queried is returned. If param_value is NULL, it is ignored.

  • param_value_size is used to specify the size in bytes of memory pointed to by param_value. This size must be ≥ size of return type as described in the Command Queue Parameter table. If param_value is NULL, it is ignored.

  • param_value_size_ret returns the actual size in bytes of data being queried by param_name. If param_value_size_ret is NULL, it is ignored.

Description

The list of supported param_name values and the information returned in param_value by clGetCommandQueueInfo is described in the Command Queue Parameter table.

Table 1. List of supported param_names by https://www.khronos.org/registry/OpenCL/specs/2.2/html/OpenCL_API.html#clGetCommandQueueInfo
cl_command_queue_info Return Type Information returned in param_value

CL_​QUEUE_​CONTEXT

cl_context

Return the context specified when the command-queue is created.

CL_​QUEUE_​DEVICE

cl_device_id

Return the device specified when the command-queue is created.

CL_​QUEUE_​REFERENCE_​COUNT3

cl_uint

Return the command-queue reference count.

CL_​QUEUE_​PROPERTIES

cl_command_queue_properties

Return the currently specified properties for the command-queue. These properties are specified by the value associated with the CL_​QUEUE_​PROPERTIES passed in properties argument in clCreateCommandQueueWithProperties, or the value of the properties argument in clCreateCommandQueue.

CL_​QUEUE_​SIZE

Missing before version 2.0.

cl_uint

Return the currently specified size for the device command-queue. This query is only supported for device command queues.

CL_​QUEUE_​DEVICE_​DEFAULT

Missing before version 2.1.

cl_command_queue

Return the current default command queue for the underlying device.

3

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.

clGetCommandQueueInfo returns CL_​SUCCESS if the function is executed successfully. Otherwise, it returns one of the following errors:

  • CL_​INVALID_​COMMAND_​QUEUE if command_queue is not a valid command-queue.

  • 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 Command Queue Parameter table, 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.

See Also

Document Notes

For more information, see the OpenCL Specification

This page is extracted from the OpenCL Specification. Fixes and changes should be made to the Specification, not directly.

Copyright (c) 2014-2020 Khronos Group. This work is licensed under a Creative Commons Attribution 4.0 International License.