DragonFly On-Line Manual Pages

ck_pr_fence_memory(3)                       DragonFly Library Functions Manual

NAME
     ck_pr_fence_memory - enforce partial ordering of all memory operations

LIBRARY
     Concurrency Kit (libck, -lck)

SYNOPSIS
     #include <ck_pr.h>

     void
     ck_pr_fence_memory();

     void
     ck_pr_fence_strict_memory();

DESCRIPTION
     The ck_pr_fence_memory(3) function enforces the ordering of any memory
     operations with respect to the invocation of the function. This function
     always serves as an implicit compiler barrier.  Achitectures implementing
     CK_MD_TSO do not emit a barrier, but compiler barrier semantics remain.
     Architectures implementing CK_MD_PSO and CK_MD_RMO always emit an
     instructions which provides the specified ordering guarantees. To force
     the unconditional emission of a memory fence, use
     ck_pr_fence_strict_memory().

EXAMPLE

           #include <ck_pr.h>

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

           void
           function(void)
           {
                   int snapshot_a;

                   ck_pr_store_int(&b, 1);
                   snapshot_a = ck_pr_load_int(&a);

                   /*
                    * Make sure previous memory operations are
                    * ordered with respect to memory operations
                    * following the ck_pr_fence_memory.
                    */
                   ck_pr_fence_memory();

                   ck_pr_store_int(&d, 3);
                   ck_pr_store_int(&c, 2);

                   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(3),
     ck_pr_fence_load_depends(3), ck_pr_fence_store(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/

                                 April 7, 2013