memory_scope
Identify if memory_scope applies to work-items in a work-group or work-items of a kernel(s).
Description
The OpenCL C programming language implements a subset of the C11 atomics (refer to section 7.17 of the C11 specification) and synchronization operations. These operations play a special role in making assignments in one work-item visible to another. A synchronization operation on one or more memory locations is either an acquire operation, a release operation, or both an acquire and release operation. (The C11 consume operation is not supported.) A synchronization operation without an associated memory location is a fence and can be either an acquire fence, a release fence or both an acquire and release fence. In addition, there are relaxed atomic operations, which are not synchronization operations, and atomic read-modify-write operations which have special characteristics
The enumerated type memory_scope specifies whether the memory ordering constraints given by memory_order apply to work-items in a work-group or work-items of a kernel(s) executing on the device or across devices (in the case of shared virtual memory). Its enumeration constants are as follows:
memory_scope_work_item
memory_scope_work_group
memory_scope_device
memory_scope_all_svm_devices
The memory_scope_work_item value for
memory_scope can only be used with
atomic_work_item_fence
with flags set to
CLK_IMAGE_MEM_FENCE.
The memory scope should only be used when performing atomic operations to global memory. Atomic operations to local memory only guarantee memory ordering in the work-group not across work-groups and therefore ignore the memory_scope value.
Copyright © 2007-2015 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.