NAME

     ck_pr_fence_load_atomic — enforce ordering of load operations to atomic read-modify-write
     operations

LIBRARY

     Concurrency Kit (libck, -lck)

SYNOPSIS

     #include <ck_pr.h>

     void
     ck_pr_fence_load_atomic(void);

     void
     ck_pr_fence_strict_load_atomic(void);

DESCRIPTION

     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.

EXAMPLE

           #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.

SEE ALSO

     ck_pr_stall(3), ck_pr_fence_atomic(3), ck_pr_fence_atomic_store(3),
     ck_pr_fence_atomic_load(3), ck_pr_fence_load_depends(3), ck_pr_fence_load_store(3),
     ck_pr_fence_store(3), ck_pr_fence_memory(3), ck_pr_barrier(3), ck_pr_fas(3), ck_pr_load(3),
     ck_pr_store(3), ck_pr_faa(3), ck_pr_inc(3), ck_pr_dec(3), ck_pr_neg(3), ck_pr_not(3),
     ck_pr_add(3), ck_pr_sub(3), ck_pr_and(3), ck_pr_or(3), ck_pr_xor(3), ck_pr_cas(3),
     ck_pr_btc(3), ck_pr_bts(3), ck_pr_btr(3)

     Additional information available at http://concurrencykit.org/

                                           May 18, 2013