2 This source code file is part of thread_mpi.
3 Written by Sander Pronk, Erik Lindahl, and possibly others.
5 Copyright (c) 2009, Sander Pronk, Erik Lindahl.
8 Redistribution and use in source and binary forms, with or without
9 modification, are permitted provided that the following conditions are met:
10 1) Redistributions of source code must retain the above copyright
11 notice, this list of conditions and the following disclaimer.
12 2) Redistributions in binary form must reproduce the above copyright
13 notice, this list of conditions and the following disclaimer in the
14 documentation and/or other materials provided with the distribution.
15 3) Neither the name of the copyright holders nor the
16 names of its contributors may be used to endorse or promote products
17 derived from this software without specific prior written permission.
19 THIS SOFTWARE IS PROVIDED BY US ''AS IS'' AND ANY
20 EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
21 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
22 DISCLAIMED. IN NO EVENT SHALL WE BE LIABLE FOR ANY
23 DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
24 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
25 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
26 ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
28 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 If you want to redistribute modifications, please consider that
31 scientific software is very special. Version control is crucial -
32 bugs must be traceable. We will be happy to consider code for
33 inclusion in the official distribution, but derived work should not
34 be called official thread_mpi. Details are found in the README & COPYING
38 #ifdef HAVE_TMPI_CONFIG_H
39 #include "tmpi_config.h"
61 int tMPI_Once(tMPI_Comm comm, void (*function)(void*), void *param,
65 int ret = TMPI_SUCCESS;
66 struct coll_sync *csync;
73 return tMPI_Error(TMPI_COMM_WORLD, TMPI_ERR_COMM);
75 myrank = tMPI_Comm_seek_rank(comm, tMPI_Get_current());
77 /* we increase our counter, and determine which coll_env we get */
78 csync = &(comm->csync[myrank]);
80 cev = &(comm->cev[csync->syncs % N_COLL_ENV]);
82 /* now do a compare-and-swap on the current_syncc */
83 syncs = tMPI_Atomic_get( &(cev->coll.current_sync));
84 if ((csync->syncs - syncs > 0) && /* check if sync was an earlier number.
85 If it is a later number, we can't
86 have been the first to arrive here. */
87 tMPI_Atomic_cas(&(cev->coll.current_sync), syncs, csync->syncs))
89 /* we're the first! */
99 void* tMPI_Once_wait(tMPI_Comm comm, void* (*function)(void*), void *param,
103 struct coll_sync *csync;
104 struct coll_env *cev;
111 tMPI_Error(TMPI_COMM_WORLD, TMPI_ERR_COMM);
114 myrank = tMPI_Comm_seek_rank(comm, tMPI_Get_current());
116 /* we increase our counter, and determine which coll_env we get */
117 csync = &(comm->csync[myrank]);
119 cev = &(comm->cev[csync->syncs % N_COLL_ENV]);
121 /* now do a compare-and-swap on the current_syncc */
122 syncs = tMPI_Atomic_get( &(cev->coll.current_sync));
123 tMPI_Atomic_memory_barrier_acq();
124 if ((csync->syncs - syncs > 0) && /* check if sync was an earlier number.
125 If it is a later number, we can't
126 have been the first to arrive here.
127 Calculating the difference instead
128 of comparing directly avoids ABA
130 tMPI_Atomic_cas(&(cev->coll.current_sync), syncs, csync->syncs))
132 /* we're the first! */
133 ret = function(param);
139 /* broadcast the output data */
142 tMPI_Atomic_memory_barrier_rel();
143 /* signal that we're done */
144 tMPI_Atomic_fetch_add(&(cev->coll.current_sync), 1);
145 /* we need to keep being in sync */
150 /* we need to wait until the current_syncc gets increased again */
154 /*tMPI_Atomic_memory_barrier();*/
155 syncs = tMPI_Atomic_get( &(cev->coll.current_sync) );
157 while (csync->syncs - syncs > 0); /* difference again due to ABA
159 tMPI_Atomic_memory_barrier_acq();
166 static void *tMPI_Shmallocator(void *prm)
168 size_t sz = *((size_t*)prm);
172 void *tMPI_Shmalloc(tMPI_Comm comm, size_t size)
174 return tMPI_Once_wait(comm, tMPI_Shmallocator, &size, NULL);