|
|
|
|
.\"
|
|
|
|
|
.\" Copyright 2013 Samy Al Bahra.
|
|
|
|
|
.\" All rights reserved.
|
|
|
|
|
.\"
|
|
|
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
|
|
|
.\" modification, are permitted provided that the following conditions
|
|
|
|
|
.\" are met:
|
|
|
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
|
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
|
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
|
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
|
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
|
|
|
.\"
|
|
|
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
|
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
|
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
|
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
|
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
|
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
|
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
|
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
|
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
|
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
|
|
|
.\" SUCH DAMAGE.
|
|
|
|
|
.\"
|
|
|
|
|
.\"
|
|
|
|
|
.Dd May 18, 2013
|
|
|
|
|
.Dt CK_PR_FENCE_LOAD_STORE 3
|
|
|
|
|
.Sh NAME
|
|
|
|
|
.Nm ck_pr_fence_load_store
|
|
|
|
|
.Nd enforce ordering of load operations to store operations
|
|
|
|
|
.Sh LIBRARY
|
|
|
|
|
Concurrency Kit (libck, \-lck)
|
|
|
|
|
.Sh SYNOPSIS
|
|
|
|
|
.In ck_pr.h
|
|
|
|
|
.Ft void
|
|
|
|
|
.Fn ck_pr_fence_load_store void
|
|
|
|
|
.Ft void
|
|
|
|
|
.Fn ck_pr_fence_strict_load_store void
|
|
|
|
|
.Sh DESCRIPTION
|
|
|
|
|
This function enforces the ordering of any memory load
|
|
|
|
|
and
|
|
|
|
|
.Fn 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
|
|
|
|
|
.Fn ck_pr_fence_load_store
|
|
|
|
|
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
|
|
|
|
|
.Fn ck_pr_fence_strict_load_store .
|
|
|
|
|
Architectures implementing CK_MD_RMO always emit a fence.
|
|
|
|
|
.Sh EXAMPLE
|
|
|
|
|
.Bd -literal -offset indent
|
|
|
|
|
|
|
|
|
|
#include <ck_pr.h>
|
|
|
|
|
|
|
|
|
|
static unsigned int a;
|
|
|
|
|
static unsigned int b;
|
|
|
|
|
|
|
|
|
|
void
|
|
|
|
|
function(void)
|
|
|
|
|
{
|
|
|
|
|
unsigned int snapshot_a;
|
|
|
|
|
|
|
|
|
|
snapshot_a = ck_pr_load_uint(&a);
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Guarantee that the load from "a" completes
|
|
|
|
|
* before the store to "b".
|
|
|
|
|
*/
|
|
|
|
|
ck_pr_fence_load_store();
|
|
|
|
|
ck_pr_store_uint(&b, 1);
|
|
|
|
|
|
|
|
|
|
return;
|
|
|
|
|
}
|
|
|
|
|
.Ed
|
|
|
|
|
.Sh RETURN VALUES
|
|
|
|
|
This function has no return value.
|
|
|
|
|
.Sh SEE ALSO
|
|
|
|
|
.Xr ck_pr_stall 3 ,
|
|
|
|
|
.Xr ck_pr_fence_atomic 3 ,
|
|
|
|
|
.Xr ck_pr_fence_atomic_store 3 ,
|
|
|
|
|
.Xr ck_pr_fence_atomic_load 3 ,
|
|
|
|
|
.Xr ck_pr_fence_load_depends 3 ,
|
|
|
|
|
.Xr ck_pr_fence_load_atomic 3 ,
|
|
|
|
|
.Xr ck_pr_fence_store 3 ,
|
|
|
|
|
.Xr ck_pr_fence_memory 3 ,
|
|
|
|
|
.Xr ck_pr_barrier 3 ,
|
|
|
|
|
.Xr ck_pr_fas 3 ,
|
|
|
|
|
.Xr ck_pr_load 3 ,
|
|
|
|
|
.Xr ck_pr_store 3 ,
|
|
|
|
|
.Xr ck_pr_faa 3 ,
|
|
|
|
|
.Xr ck_pr_inc 3 ,
|
|
|
|
|
.Xr ck_pr_dec 3 ,
|
|
|
|
|
.Xr ck_pr_neg 3 ,
|
|
|
|
|
.Xr ck_pr_not 3 ,
|
|
|
|
|
.Xr ck_pr_add 3 ,
|
|
|
|
|
.Xr ck_pr_sub 3 ,
|
|
|
|
|
.Xr ck_pr_and 3 ,
|
|
|
|
|
.Xr ck_pr_or 3 ,
|
|
|
|
|
.Xr ck_pr_xor 3 ,
|
|
|
|
|
.Xr ck_pr_cas 3 ,
|
|
|
|
|
.Xr ck_pr_btc 3 ,
|
|
|
|
|
.Xr ck_pr_bts 3 ,
|
|
|
|
|
.Xr ck_pr_btr 3
|
|
|
|
|
.Pp
|
|
|
|
|
Additional information available at http://concurrencykit.org/
|
