xenial (3) ck_pr_fence_load_atomic.3.gz

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