Description

// Requires OpenCL C 3.0 or newer and both the __opencl_c_atomic_order_seq_cst
// and __opencl_c_atomic_scope_device features.
void atomic_flag_clear(volatile __global atomic_flag *object)
void atomic_flag_clear(volatile __local atomic_flag *object)

// Requires OpenCL C 2.0, or OpenCL C 3.0 or newer and all of the
// __opencl_c_generic_address_space, __opencl_c_atomic_order_seq_cst and
// __opencl_c_atomic_scope_device features.
void atomic_flag_clear(volatile atomic_flag *object)

// Requires OpenCL C 3.0 or newer and the __opencl_c_atomic_scope_device
// feature.
void atomic_flag_clear_explicit(
    volatile __global atomic_flag *object,
    memory_order order)
void atomic_flag_clear_explicit(
    volatile __local atomic_flag *object,
    memory_order order)

// Requires OpenCL C 2.0, or OpenCL C 3.0 or newer and both the
// __opencl_c_generic_address_space and __opencl_c_atomic_scope_device
// features.
void atomic_flag_clear_explicit(
    volatile atomic_flag *object,
    memory_order order)

// Requires OpenCL C 3.0 or newer.
void atomic_flag_clear_explicit(
    volatile __global atomic_flag *object,
    memory_order order,
    memory_scope scope)
void atomic_flag_clear_explicit(
    volatile __local atomic_flag *object,
    memory_order order,
    memory_scope scope)

// Requires OpenCL C 2.0, or OpenCL C 3.0 or newer and the
// __opencl_c_generic_address_space feature.
void atomic_flag_clear_explicit(
    volatile atomic_flag *object,
    memory_order order,
    memory_scope scope)

The order argument shall not be memory_order_acquire nor memory_order_acq_rel. Atomically sets the value pointed to by object to false. Memory is affected according to the value of order.

The non-explicit atomic_flag_clear function requires support for OpenCL C 2.0, or OpenCL C 3.0 or newer and both the __opencl_c_atomic_order_seq_cst and __opencl_c_atomic_scope_device features. For the explicit variants, memory order and scope enumerations must respect the restrictions section below.
The function variants that use the generic address space, i.e. no explicit address space is listed, require support for OpenCL C 2.0, or OpenCL C 3.0 or newer and the __opencl_c_generic_address_space feature.

See Also

atomicFunctions, atomicTypes, atomic_compare_exchange, atomic_exchange, atomic_fetch_key, atomic_flag, atomic_flag_clear, atomic_flag_test_and_set, atomic_flag_test_and_set_explicit, atomic_init, atomic_load, atomic_store, atomic_work_item_fence

Document Notes

For more information, see the OpenCL C Specification

This page is extracted from the OpenCL C 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