atomic_work_item_fence.adoc

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atomic_work_item_fence

atomic_work_item_fence functions.

void atomic_work_item_fence(cl_mem_fence_flags flags,
                            memory_order order,
                            memory_scope scope)

Parameters

flags

Must be set to CLK_GLOBAL_MEM_FENCE, CLK_LOCAL_MEM_FENCE, CLK_IMAGE_MEM_FENCE or a combination of these values ORed together; otherwise the behavior is undefined. The behavior of calling atomic_work_item_fence with CLK_IMAGE_MEM_FENCE ORed together with either CLK_GLOBAL_MEM_FENCE or CLK_LOCAL_MEM_FENCE is equivalent to calling atomic_work_item_fence individually for CLK_IMAGE_MEM_FENCE and the other flags. Passing both CLK_GLOBAL_MEM_FENCE and CLK_LOCAL_MEM_FENCE to atomic_work_item_fence will synchronize memory operations to both local and global memory through some shared atomic action, as described in section 3.3.6.2 of the OpenCL API specficiation.

order

scope

== Description

Depending on the value of order, this operation:

• has no effects, if order == memory_order_relaxed.

• is an acquire fence, if order == memory_order_acquire.

• is a release fence, if order == memory_order_release.

• is both an acquire fence and a release fence, if order == memory_order_acq_rel.

• is a sequentially consistent acquire and release fence, if order == memory_order_seq_cst.

For images declared with the read_write qualifier, the atomic_work_item_fence must be called to make sure that writes to the image by a work-item become visible to that workitem on subsequent reads to that image by that work-item.

Also see

Atomic Functions

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