int tMPI_Scan(void* sendbuf, void* recvbuf, int count,
tMPI_Datatype datatype, tMPI_Op op, tMPI_Comm comm)
{
struct tmpi_thread *cur=tMPI_Get_current();
int myrank=tMPI_Comm_seek_rank(comm, cur);
int N=tMPI_Comm_N(comm);
int prev=myrank - 1; /* my previous neighbor */
int next=myrank + 1; /* my next neighbor */
#ifdef TMPI_PROFILE
tMPI_Profile_count_start(cur);
#endif
#ifdef TMPI_TRACE
tMPI_Trace_print("tMPI_Scan(%p, %p, %d, %p, %p, %p)",
sendbuf, recvbuf, count, datatype, op, comm);
#endif
if (count==0)
return TMPI_SUCCESS;
if (!recvbuf)
{
return tMPI_Error(comm, TMPI_ERR_BUF);
}
if (sendbuf==TMPI_IN_PLACE)
{
sendbuf=recvbuf;
}
/* we set our send and recv buffers */
tMPI_Atomic_ptr_set(&(comm->reduce_sendbuf[myrank]),sendbuf);
tMPI_Atomic_ptr_set(&(comm->reduce_recvbuf[myrank]),recvbuf);
/* now wait for the previous rank to finish */
if (myrank > 0)
{
void *a, *b;
int ret;
#if defined(TMPI_PROFILE) && defined(TMPI_CYCLE_COUNT)
tMPI_Profile_wait_start(cur);
#endif
/* wait for the previous neighbor's data to be ready */
tMPI_Event_wait( &(comm->csync[myrank].events[prev]) );
tMPI_Event_process( &(comm->csync[myrank].events[prev]), 1);
#if defined(TMPI_PROFILE) && defined(TMPI_CYCLE_COUNT)
tMPI_Profile_wait_stop(cur, TMPIWAIT_Reduce);
#endif
#ifdef TMPI_DEBUG
printf("%d: scanning with %d \n", myrank, prev, iteration);
fflush(stdout);
#endif
/* now do the reduction */
if (prev > 0)
{
a = (void*)tMPI_Atomic_ptr_get(&(comm->reduce_recvbuf[prev]));
}
else
{
a = (void*)tMPI_Atomic_ptr_get(&(comm->reduce_sendbuf[prev]));
}
b = sendbuf;
if ((ret=tMPI_Reduce_run_op(recvbuf, a, b, datatype,
count, op, comm)) != TMPI_SUCCESS)
{
return ret;
}
/* signal to my previous neighbor that I'm done with the data */
tMPI_Event_signal( &(comm->csync[prev].events[prev]) );
}
else
{
if (sendbuf != recvbuf)
{
/* copy the data if this is rank 0, and not MPI_IN_PLACE */
memcpy(recvbuf, sendbuf, count*datatype->size);
}
}
if (myrank < N-1)
{
/* signal to my next neighbor that I have the data */
tMPI_Event_signal( &(comm->csync[next].events[myrank]) );
/* and wait for my next neighbor to finish */
tMPI_Event_wait( &(comm->csync[myrank].events[myrank]) );
tMPI_Event_process( &(comm->csync[myrank].events[myrank]), 1);
}
#if defined(TMPI_PROFILE) && defined(TMPI_CYCLE_COUNT)
tMPI_Profile_wait_start(cur);
#endif
/*tMPI_Barrier_wait( &(comm->barrier));*/
#if defined(TMPI_PROFILE)
/*tMPI_Profile_wait_stop(cur, TMPIWAIT_Reduce);*/
tMPI_Profile_count_stop(cur, TMPIFN_Scan);
#endif
return TMPI_SUCCESS;
}
void tMPI_Mult_recv(tMPI_Comm comm, struct coll_env *cev, int rank,
int index, int expected_tag, tMPI_Datatype recvtype,
size_t recvsize, void *recvbuf, int *ret)
{
size_t sendsize=cev->met[rank].bufsize[index];
/* check tags, types */
if ((cev->met[rank].datatype != recvtype ) ||
(cev->met[rank].tag != expected_tag))
{
*ret=tMPI_Error(comm, TMPI_ERR_MULTI_MISMATCH);
}
if (sendsize) /* we allow NULL ptrs if there's nothing to xmit */
{
void *srcbuf;
#ifdef USE_COLLECTIVE_COPY_BUFFER
tmpi_bool decrease_ctr=FALSE;
#endif
if ( sendsize > recvsize )
{
*ret=tMPI_Error(comm, TMPI_ERR_XFER_BUFSIZE);
return;
}
if ( cev->met[rank].buf == recvbuf )
{
*ret=tMPI_Error(TMPI_COMM_WORLD,TMPI_ERR_XFER_BUF_OVERLAP);
return;
}
/* get source buffer */
#ifdef USE_COLLECTIVE_COPY_BUFFER
if ( !(cev->met[rank].using_cb))
#endif
{
srcbuf=cev->met[rank].buf[index];
}
#ifdef USE_COLLECTIVE_COPY_BUFFER
else
{
srcbuf=tMPI_Atomic_ptr_get(&(cev->met[rank].cpbuf[index]));
tMPI_Atomic_memory_barrier_acq();
if(!srcbuf)
{ /* there was (as of yet) no copied buffer */
void *try_again_srcbuf;
/* we need to try checking the pointer again after we increase
the read counter, signaling that one more thread
is reading. */
tMPI_Atomic_add_return(&(cev->met[rank].buf_readcount), 1);
/* a full memory barrier */
tMPI_Atomic_memory_barrier();
try_again_srcbuf=tMPI_Atomic_ptr_get(
&(cev->met[rank].cpbuf[index]));
if (!try_again_srcbuf)
{
/* apparently the copied buffer is not ready yet. We
just use the real source buffer. We have already
indicated we're reading from the regular buf. */
srcbuf=cev->met[rank].buf[index];
decrease_ctr=TRUE;
}
else
{
/* We tried again, and this time there was a copied buffer.
We use that, and indicate that we're not reading from the
regular buf. This case should be pretty rare. */
tMPI_Atomic_fetch_add(&(cev->met[rank].buf_readcount),-1);
tMPI_Atomic_memory_barrier_acq();
srcbuf=try_again_srcbuf;
}
}
#ifdef TMPI_PROFILE
if (srcbuf)
tMPI_Profile_count_buffered_coll_xfer(tMPI_Get_current());
#endif
}
#endif
/* copy data */
memcpy((char*)recvbuf, srcbuf, sendsize);
#ifdef TMPI_PROFILE
tMPI_Profile_count_coll_xfer(tMPI_Get_current());
#endif
#ifdef USE_COLLECTIVE_COPY_BUFFER
if (decrease_ctr)
{
/* we decrement the read count; potentially releasing the buffer. */
tMPI_Atomic_memory_barrier_rel();
tMPI_Atomic_fetch_add( &(cev->met[rank].buf_readcount), -1);
}
#endif
}
/* signal one thread ready */
{
int reta;
tMPI_Atomic_memory_barrier_rel();
reta=tMPI_Atomic_add_return( &(cev->met[rank].n_remaining), -1);
if (reta <= 0)
{
tMPI_Event_signal( &(cev->met[rank].send_ev) );
}
}
}
void tMPI_Post_multi(struct coll_env *cev, int myrank, int index,
int tag, tMPI_Datatype datatype, size_t bufsize,
void *buf, int n_remaining, int synct, int dest)
{
int i;
#ifdef USE_COLLECTIVE_COPY_BUFFER
/* decide based on the number of waiting threads */
tmpi_bool using_cb=(bufsize < (size_t)(n_remaining*COPY_BUFFER_SIZE));
cev->met[myrank].using_cb=using_cb;
if (using_cb)
{
/* we set it to NULL initially */
/*cev->met[myrank].cpbuf[index]=NULL;*/
tMPI_Atomic_ptr_set(&(cev->met[myrank].cpbuf[index]), NULL);
tMPI_Atomic_set(&(cev->met[myrank].buf_readcount), 0);
}
#endif
cev->met[myrank].tag=tag;
cev->met[myrank].datatype=datatype;
cev->met[myrank].buf[index]=buf;
cev->met[myrank].bufsize[index]=bufsize;
tMPI_Atomic_set(&(cev->met[myrank].n_remaining), n_remaining);
tMPI_Atomic_memory_barrier_rel();
tMPI_Atomic_set(&(cev->met[myrank].current_sync), synct);
/* publish availability. */
if (dest<0)
{
for(i=0;i<cev->N;i++)
{
if (i != myrank)
tMPI_Event_signal( &(cev->met[i].recv_ev) );
}
}
else
{
tMPI_Event_signal( &(cev->met[dest].recv_ev) );
}
#ifdef USE_COLLECTIVE_COPY_BUFFER
/* becase we've published availability, we can start copying --
possibly in parallel with the receiver */
if (using_cb)
{
struct tmpi_thread *cur=tMPI_Get_current();
/* copy the buffer locally. First allocate */
cev->met[myrank].cb=tMPI_Copy_buffer_list_get( &(cur->cbl_multi) );
if (cev->met[myrank].cb->size < bufsize)
{
fprintf(stderr, "ERROR: cb size too small\n");
exit(1);
}
/* copy to the new buf */
memcpy(cev->met[myrank].cb->buf, buf, bufsize);
/* post the new buf */
tMPI_Atomic_memory_barrier_rel();
/*cev->met[myrank].cpbuf[index]=cev->met[myrank].cb->buf;*/
tMPI_Atomic_ptr_set(&(cev->met[myrank].cpbuf[index]),
cev->met[myrank].cb->buf);
}
#endif
}
int tMPI_Alltoall(void* sendbuf, int sendcount, tMPI_Datatype sendtype,
void* recvbuf, int recvcount, tMPI_Datatype recvtype,
tMPI_Comm comm)
{
int synct;
struct coll_env *cev;
int myrank;
int ret = TMPI_SUCCESS;
int i;
size_t sendsize = sendtype->size*sendcount;
size_t recvsize = recvtype->size*recvcount;
int n_remaining;
struct tmpi_thread *cur = tMPI_Get_current();
#ifdef TMPI_PROFILE
tMPI_Profile_count_start(cur);
#endif
#ifdef TMPI_TRACE
tMPI_Trace_print("tMPI_Alltoall(%p, %d, %p, %p, %d, %p, %p)",
sendbuf, sendcount, sendtype,
recvbuf, recvcount, recvtype, comm);
#endif
if (!comm)
{
return tMPI_Error(TMPI_COMM_WORLD, TMPI_ERR_COMM);
}
if (!sendbuf || !recvbuf) /* don't do pointer arithmetic on a NULL ptr */
{
return tMPI_Error(comm, TMPI_ERR_BUF);
}
myrank = tMPI_Comm_seek_rank(comm, cur);
/* we increase our counter, and determine which coll_env we get */
cev = tMPI_Get_cev(comm, myrank, &synct);
/* post our pointers */
/* we set up multiple posts, so no Post_multi */
cev->met[myrank].tag = TMPI_ALLTOALL_TAG;
cev->met[myrank].datatype = sendtype;
tMPI_Atomic_set( &(cev->met[myrank].n_remaining), cev->N-1 );
for (i = 0; i < comm->grp.N; i++)
{
cev->met[myrank].bufsize[i] = sendsize;
cev->met[myrank].buf[i] = (char*)sendbuf+sendsize*i;
cev->met[myrank].read_data[i] = FALSE;
}
tMPI_Atomic_memory_barrier_rel();
tMPI_Atomic_set(&(cev->met[myrank].current_sync), synct);
/* post availability */
for (i = 0; i < cev->N; i++)
{
if (i != myrank)
{
tMPI_Event_signal( &(cev->met[i].recv_ev) );
}
}
/* we don't do the copy buffer thing here because it's pointless:
the processes have to synchronize anyway, because they all
send and receive. */
/* do root transfer */
tMPI_Coll_root_xfer(comm, sendtype, recvtype,
sendsize, recvsize,
(char*)sendbuf+sendsize*myrank,
(char*)recvbuf+recvsize*myrank, &ret);
cev->met[myrank].read_data[myrank] = TRUE;
/* and poll data availability */
n_remaining = cev->N-1;
while (n_remaining > 0)
{
#if defined(TMPI_PROFILE) && defined(TMPI_CYCLE_COUNT)
tMPI_Profile_wait_start(cur);
#endif
tMPI_Event_wait( &(cev->met[myrank]).recv_ev );
#if defined(TMPI_PROFILE) && defined(TMPI_CYCLE_COUNT)
tMPI_Profile_wait_stop(cur, TMPIWAIT_Coll_recv);
#endif
for (i = 0; i < cev->N; i++)
{
if ((!cev->met[myrank].read_data[i]) &&
(tMPI_Atomic_get(&(cev->met[i].current_sync)) == synct))
{
tMPI_Event_process( &(cev->met[myrank]).recv_ev, 1);
tMPI_Mult_recv(comm, cev, i, myrank, TMPI_ALLTOALL_TAG,
recvtype, recvsize, (char*)recvbuf+recvsize*i,
&ret);
if (ret != TMPI_SUCCESS)
{
return ret;
}
cev->met[myrank].read_data[i] = TRUE;
n_remaining--;
}
}
}
/* and wait until everybody is done copying our data */
tMPI_Wait_for_others(cev, myrank);
#ifdef TMPI_PROFILE
tMPI_Profile_count_stop(cur, TMPIFN_Alltoall);
#endif
return ret;
}
