DragonFly On-Line Manual Pages

CK_PR_FENCE_ATOMIC(3)                       DragonFly Library Functions Manual

NAME
     ck_pr_fence_atomic - enforce partial ordering of atomic read-modify-write
     operations

LIBRARY
     Concurrency Kit (libck, -lck)

SYNOPSIS
     #include <ck_pr.h>

     void
     ck_pr_fence_atomic(void);

     void
     ck_pr_fence_strict_atomic(void);

DESCRIPTION
     The ck_pr_fence_atomic() function enfores the ordering of any atomic
     read-modify-write operations relative to the invocation of the function.
     This function always serve as an implicit compiler barrier. On
     architectures implementing CK_MD_TSO, this operation only serves as a
     compiler barrier and no fences are emitted. On architectures implementing
     CK_MD_PSO and CK_MD_RMO, a store fence is emitted. To force the
     unconditional emission of a fence, use ck_pr_fence_strict_atomic().

EXAMPLE

           #include <ck_pr.h>

           static int a = 0;
           static int b = 0;
           static int c = 0;

           void
           function(void)
           {

                   ck_pr_fas_int(&a, 1);

                   /*
                    * Guarantee that the update to a is completed
                    * with respect to the updates of b and c.
                    */
                   ck_pr_fence_atomic();
                   ck_pr_fas_int(&b, 2);
                   ck_pr_fas_int(&c, 2);

                   return;
           }

RETURN VALUES
     This function has no return value.

SEE ALSO
     ck_pr_stall(3), ck_pr_fence_atomic_store(3), ck_pr_fence_atomic_load(3),
     ck_pr_fence_store(3), ck_pr_fence_load(3), ck_pr_fence_load_atomic(3),
     ck_pr_fence_load_store(3), ck_pr_fence_load_depends(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 16, 2013