C Specification

To release a device, call the function:

// Provided by CL_VERSION_1_2
cl_int clReleaseDevice(
    cl_device_id device);
clReleaseDevice is missing before version 1.2.

Parameters

  • device is the OpenCL device to release.

Description

clReleaseDevice decrements the device reference count if device is a valid sub-device created by a call to clCreateSubDevices. If device is a root level device i.e. a cl_device_id returned by clGetDeviceIDs, the device reference count remains unchanged.

clReleaseDevice returns CL_SUCCESS if the function is executed successfully. Otherwise, it returns one of the following errors:

  • CL_INVALID_DEVICE if device is not a valid device.

  • 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.

After the device reference count becomes zero and all the objects attached to device (such as command-queues) are released, the device object is deleted. Using this function to release a reference that was not obtained by creating the object or by calling clRetainDevice causes undefined behavior.

See Also

CL_VERSION_1_2, clRetainDevice, cl_device_id

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

Copyright 2014-2025 The Khronos Group Inc.

SPDX-License-Identifier: CC-BY-4.0