ck_pr_fence_load_atomic(3)

Usage

#include <ck_pr.h>

void

ck_pr_fence_load_atomic(void);

void

ck_pr_fence_strict_load_atomic(void);

Library

Concurrency Kit (libck, -lck)

Overview

This function enforces the ordering of any memory load and ck_pr_load(3) operations with respect to store operations relative to the invocation of the function. Any store operations that were committed on remote processors and received by the calling processor before the invocation of ck_pr_fence_load_atomic() is also be made visible only after a call to the ck_pr_fence_load family of functions. This function always serves as an implicit compiler barrier. On architectures with CK_MD_TSO or CK_MD_PSO specified (total store ordering and partial store ordering respectively), this operation only serves as a compiler barrier and no fence instructions will be emitted. To force the unconditional emission of a load fence, use ck_pr_fence_strict_load_atomic(). Architectures implementing CK_MD_RMO always emit a fence.

Examples

#include <ck_pr.h>
static unsigned int a;
static unsigned int b;
void
function(void)
{
	unsigned int snapshot_a, snapshot_b;
	snapshot_a = ck_pr_load_uint(&a);
	/*
	 * Guarantee that the load from "a" completes
	 * before the update to "b".
	 */
	ck_pr_fence_load_atomic();
	ck_pr_fas_uint(&b, 1);
	return;
}

Return values

This function has no return value.

Releases

5 releases since Debian 8 (Jessie); the text changed 1 time.

8
9–13

ck_pr_stall(3) busy-wait primitive ck_pr_fence_atomic(3) enforce partial ordering of atomic read-modify-write operations ck_pr_fence_atomic_store(3) enforce ordering of atomic read-modify-write operations to store operations ck_pr_fence_atomic_load(3) enforce ordering of atomic read-modify-write operations to load operations ck_pr_fence_load_depends(3) data dependency barrier ck_pr_fence_load_store(3) enforce ordering of load operations to store operations ck_pr_fence_store(3) enforce partial ordering of store operations ck_pr_fence_memory(3) enforce partial ordering of all memory operations ck_pr_barrier(3) compiler optimization barrier ck_pr_fas(3) atomic swap operations ck_pr_load(3) atomic volatile load operations ck_pr_store(3) atomic volatile store operations ck_pr_faa(3) atomic fetch-and-add operations ck_pr_inc(3) atomic increment operations ck_pr_dec(3) atomic decrement operations ck_pr_neg(3) atomic negation operations ck_pr_not(3) atomic complement operations ck_pr_add(3) atomic addition operations ck_pr_sub(3) atomic subtraction operations ck_pr_and(3) atomic bitwise-and operations ck_pr_or(3) atomic bitwise-or operations ck_pr_xor(3) atomic bitwise-xor operations ck_pr_cas(3) atomic compare-and-swap operations ck_pr_btc(3) atomic bit test-and-complement operations ck_pr_bts(3) atomic bit test-and-set operations ck_pr_btr(3) atomic bit test-and-reset operations

Referred to by

ck_pr_fence_load(3) enforce partial ordering of load operations ck_pr_fence_store(3) enforce partial ordering of store operations ck_pr_fence_atomic(3) enforce partial ordering of atomic read-modify-write operations ck_pr_fence_load_store(3) enforce ordering of load operations to store operations ck_pr_fence_store_load(3) enforce ordering of store operations to load operations ck_pr_fence_atomic_load(3) enforce ordering of atomic read-modify-write operations to load operations ck_pr_fence_atomic_store(3) enforce ordering of atomic read-modify-write operations to store operations ck_pr_fence_load_depends(3) data dependency barrier ck_pr_fence_store_atomic(3) enforce ordering of store operations to load operations