C Specification

To release a semaphore object, call the function

// Provided by cl_khr_semaphore
cl_int clReleaseSemaphoreKHR(
    cl_semaphore_khr sema_object);
clReleaseSemaphoreKHR is provided by the cl_khr_semaphore extension.

Parameters

  • sema_object specifies the semaphore object to be released.

Description

The sema_object reference count is decremented.

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

  • CL_INVALID_SEMAPHORE_KHR if sema_object is not a valid semaphore object.

  • 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 reference count becomes zero and commands queued for execution on a command-queue(s) that use sema_object have finished, the semaphore object is deleted. Using this function to release a reference that was not obtained by creating the object via clCreateSemaphoreWithPropertiesKHR or by calling clRetainSemaphoreKHR causes undefined behavior.

See Also

cl_khr_semaphore, cl_semaphore_khr

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