/* This routine serves two purposes:
* - the allreduce acts as a kind of Barrier,
* which avoids, that we have incoming fragments
* on the new communicator before everybody has set
* up the comm structure.
* - some components (e.g. the collective MagPIe component
* might want to generate new communicators and communicate
* using the new comm. Thus, it can just be called after
* the 'barrier'.
*
* The reason that this routine is in comm_cid and not in
* comm.c is, that this file contains the allreduce implementations
* which are required, and thus we avoid having duplicate code...
*/
int ompi_comm_activate ( ompi_communicator_t** newcomm,
ompi_communicator_t* comm,
ompi_communicator_t* bridgecomm,
void* local_leader,
void* remote_leader,
int mode,
int send_first )
{
int ret = 0;
int ok=0, gok=0;
ompi_comm_cid_allredfct* allredfnct;
/* Step 1: the barrier, after which it is allowed to
* send messages over the new communicator
*/
switch (mode)
{
case OMPI_COMM_CID_INTRA:
allredfnct=(ompi_comm_cid_allredfct*)ompi_comm_allreduce_intra;
break;
case OMPI_COMM_CID_INTER:
allredfnct=(ompi_comm_cid_allredfct*)ompi_comm_allreduce_inter;
break;
case OMPI_COMM_CID_INTRA_BRIDGE:
allredfnct=(ompi_comm_cid_allredfct*)ompi_comm_allreduce_intra_bridge;
break;
case OMPI_COMM_CID_INTRA_OOB:
allredfnct=(ompi_comm_cid_allredfct*)ompi_comm_allreduce_intra_oob;
break;
default:
return MPI_UNDEFINED;
break;
}
if (MPI_UNDEFINED != (*newcomm)->c_local_group->grp_my_rank) {
/* Initialize the PML stuff in the newcomm */
if ( OMPI_SUCCESS != (ret = MCA_PML_CALL(add_comm(*newcomm))) ) {
goto bail_on_error;
}
OMPI_COMM_SET_PML_ADDED(*newcomm);
}
(allredfnct)(&ok, &gok, 1, MPI_MIN, comm, bridgecomm,
local_leader, remote_leader, send_first );
/**
* Check to see if this process is in the new communicator.
*
* Specifically, this function is invoked by all proceses in the
* old communicator, regardless of whether they are in the new
* communicator or not. This is because it is far simpler to use
* MPI collective functions on the old communicator to determine
* some data for the new communicator (e.g., remote_leader) than
* to kludge up our own pseudo-collective routines over just the
* processes in the new communicator. Hence, *all* processes in
* the old communicator need to invoke this function.
*
* That being said, only processes in the new communicator need to
* select a coll module for the new communicator. More
* specifically, proceses who are not in the new communicator
* should *not* select a coll module -- for example,
* ompi_comm_rank(newcomm) returns MPI_UNDEFINED for processes who
* are not in the new communicator. This can cause errors in the
* selection / initialization of a coll module. Plus, it's
* wasteful -- processes in the new communicator will end up
* freeing the new communicator anyway, so we might as well leave
* the coll selection as NULL (the coll base comm unselect code
* handles that case properly).
*/
if (MPI_UNDEFINED == (*newcomm)->c_local_group->grp_my_rank) {
return OMPI_SUCCESS;
}
/* Let the collectives components fight over who will do
collective on this new comm. */
if (OMPI_SUCCESS != (ret = mca_coll_base_comm_select(*newcomm))) {
goto bail_on_error;
}
/* For an inter communicator, we have to deal with the potential
* problem of what is happening if the local_comm that we created
* has a lower CID than the parent comm. This is not a problem
* as long as the user calls MPI_Comm_free on the inter communicator.
* However, if the communicators are not freed by the user but released
* by Open MPI in MPI_Finalize, we walk through the list of still available
* communicators and free them one by one. Thus, local_comm is freed before
* the actual inter-communicator. However, the local_comm pointer in the
* inter communicator will still contain the 'previous' address of the local_comm
* and thus this will lead to a segmentation violation. In order to prevent
* that from happening, we increase the reference counter local_comm
* by one if its CID is lower than the parent. We cannot increase however
* its reference counter if the CID of local_comm is larger than
* the CID of the inter communicators, since a regular MPI_Comm_free would
* leave in that the case the local_comm hanging around and thus we would not
* recycle CID's properly, which was the reason and the cause for this trouble.
*/
if ( OMPI_COMM_IS_INTER(*newcomm)) {
if ( OMPI_COMM_CID_IS_LOWER(*newcomm, comm)) {
OMPI_COMM_SET_EXTRA_RETAIN (*newcomm);
OBJ_RETAIN (*newcomm);
}
}
return OMPI_SUCCESS;
bail_on_error:
OBJ_RELEASE(*newcomm);
*newcomm = MPI_COMM_NULL;
return ret;
}
struct ompi_communicator_t* mca_coll_hierarch_get_llcomm (int root,
mca_coll_hierarch_module_t *hierarch_module,
int* llroot,
int* lroot)
{
struct ompi_communicator_t *llcomm=NULL;
struct ompi_group_t *llgroup=NULL;
struct ompi_group_t *group=NULL;
struct mca_coll_hierarch_llead_t *llead=NULL;
int found, i, rc, num_llead, offset;
int rank = ompi_comm_rank (hierarch_module->hier_comm);
int color;
/* determine what our offset of root is in the colorarr */
offset = mca_coll_hierarch_get_offset ( root,
hierarch_module->hier_num_colorarr,
hierarch_module->hier_colorarr );
num_llead = opal_pointer_array_get_size ( &(hierarch_module->hier_llead) );
for ( found=0, i=0; i < num_llead; i++ ) {
llead = (struct mca_coll_hierarch_llead_t *) opal_pointer_array_get_item (
&(hierarch_module->hier_llead), i );
if ( NULL == llead ) {
continue;
}
if (llead->offset == offset ) {
found = 1;
break;
}
#if 0
else if () {
/* the offset of root = maxoffset of this color and
* the offset on llead is larger then offset of root.
* then we can also use this llead structure
*/
}
#endif
}
if ( !found ) {
/* allocate a new llead element */
llead = (struct mca_coll_hierarch_llead_t *) malloc (
sizeof(struct mca_coll_hierarch_llead_t));
if ( NULL == llead ) {
return NULL;
}
/* generate the list of lleaders with this offset */
mca_coll_hierarch_get_all_lleaders ( rank, hierarch_module, llead, offset );
color = MPI_UNDEFINED;
if ( llead->am_lleader ) {
color = 1;
}
/* create new lleader subcommunicator */
rc = ompi_comm_split ( hierarch_module->hier_comm, color, root, &llcomm, 0);
if ( OMPI_SUCCESS != rc ) {
return NULL;
}
if ( OMPI_COMM_CID_IS_LOWER ( llcomm, hierarch_module->hier_comm ) ) {
/* Mark the communicator as 'extra retain' and increase the
reference count by one more. See ompi_comm_activate
for detailed explanation. */
OMPI_COMM_SET_EXTRA_RETAIN (llcomm);
OBJ_RETAIN(llcomm);
}
llead->llcomm = llcomm;
/* Store the new element on the hierarch_module struct */
opal_pointer_array_add ( &(hierarch_module->hier_llead), llead);
}
llcomm = llead->llcomm;
*lroot = llead->my_lleader;
*llroot = MPI_UNDEFINED;
if ( MPI_COMM_NULL != llcomm ) {
group = hierarch_module->hier_comm->c_local_group;
llgroup = llcomm->c_local_group;
rc = ompi_group_translate_ranks ( group, 1, &root, llgroup, llroot);
if ( OMPI_SUCCESS != rc ) {
return NULL;
}
}
return llcomm;
}
static int ompi_comm_activate_nb_complete (ompi_comm_request_t *request)
{
ompi_comm_cid_context_t *context = (ompi_comm_cid_context_t *) request->context;
int ret;
/**
* Check to see if this process is in the new communicator.
*
* Specifically, this function is invoked by all proceses in the
* old communicator, regardless of whether they are in the new
* communicator or not. This is because it is far simpler to use
* MPI collective functions on the old communicator to determine
* some data for the new communicator (e.g., remote_leader) than
* to kludge up our own pseudo-collective routines over just the
* processes in the new communicator. Hence, *all* processes in
* the old communicator need to invoke this function.
*
* That being said, only processes in the new communicator need to
* select a coll module for the new communicator. More
* specifically, proceses who are not in the new communicator
* should *not* select a coll module -- for example,
* ompi_comm_rank(newcomm) returns MPI_UNDEFINED for processes who
* are not in the new communicator. This can cause errors in the
* selection / initialization of a coll module. Plus, it's
* wasteful -- processes in the new communicator will end up
* freeing the new communicator anyway, so we might as well leave
* the coll selection as NULL (the coll base comm unselect code
* handles that case properly).
*/
if (MPI_UNDEFINED == (context->newcomm)->c_local_group->grp_my_rank) {
return OMPI_SUCCESS;
}
/* Let the collectives components fight over who will do
collective on this new comm. */
if (OMPI_SUCCESS != (ret = mca_coll_base_comm_select(context->newcomm))) {
OBJ_RELEASE(context->newcomm);
*context->newcommp = MPI_COMM_NULL;
return ret;
}
/* For an inter communicator, we have to deal with the potential
* problem of what is happening if the local_comm that we created
* has a lower CID than the parent comm. This is not a problem
* as long as the user calls MPI_Comm_free on the inter communicator.
* However, if the communicators are not freed by the user but released
* by Open MPI in MPI_Finalize, we walk through the list of still available
* communicators and free them one by one. Thus, local_comm is freed before
* the actual inter-communicator. However, the local_comm pointer in the
* inter communicator will still contain the 'previous' address of the local_comm
* and thus this will lead to a segmentation violation. In order to prevent
* that from happening, we increase the reference counter local_comm
* by one if its CID is lower than the parent. We cannot increase however
* its reference counter if the CID of local_comm is larger than
* the CID of the inter communicators, since a regular MPI_Comm_free would
* leave in that the case the local_comm hanging around and thus we would not
* recycle CID's properly, which was the reason and the cause for this trouble.
*/
if (OMPI_COMM_IS_INTER(context->newcomm)) {
if (OMPI_COMM_CID_IS_LOWER(context->newcomm, context->comm)) {
OMPI_COMM_SET_EXTRA_RETAIN (context->newcomm);
OBJ_RETAIN (context->newcomm);
}
}
/* done */
return OMPI_SUCCESS;
}
/*
* Init module on the communicator
*/
int mca_coll_hierarch_module_enable (mca_coll_base_module_t *module,
struct ompi_communicator_t *comm)
{
int color;
int size, rank, ret=OMPI_SUCCESS;
struct ompi_communicator_t *lcomm=NULL;
struct ompi_communicator_t *llcomm=NULL;
struct mca_coll_hierarch_llead_t *llead=NULL;
mca_coll_hierarch_module_t *hierarch_module = (mca_coll_hierarch_module_t *) module;
rank = ompi_comm_rank(comm);
size = ompi_comm_size(comm);
color = hierarch_module->hier_colorarr[rank];
/* Generate the subcommunicator based on the color returned by
the previous function. */
ret = ompi_comm_split ( comm, color, rank, &lcomm, 0 );
if ( OMPI_SUCCESS != ret ) {
goto exit;
}
if ( OMPI_COMM_CID_IS_LOWER ( lcomm, comm ) ) {
/* Mark the communicator as 'extra retain' and increase the
reference count by one more. See ompi_comm_activate
for detailed comments
*/
OMPI_COMM_SET_EXTRA_RETAIN (lcomm);
OBJ_RETAIN(lcomm);
}
hierarch_module->hier_comm = comm;
hierarch_module->hier_lcomm = lcomm;
hierarch_module->hier_num_reqs = 2 * size;
hierarch_module->hier_reqs = (ompi_request_t **) malloc (sizeof(ompi_request_t)*size*2);
if ( NULL == hierarch_module->hier_reqs ) {
goto exit;
}
/* allocate a certain number of the hierarch_llead structures, which store
information about local leader and the according subcommunicators
*/
llead = (struct mca_coll_hierarch_llead_t * ) malloc (
sizeof(struct mca_coll_hierarch_llead_t));
if ( NULL == llead ) {
goto exit;
}
/* These two routines set all relevant entries in the mca_coll_base_comm_t
* structure. The first one makes all entries which are independent of the
* offset (and have to be done only once per module. The second one is
* depending on the offset, and has to be called therefore every time we need
* a new llcomm
*/
mca_coll_hierarch_get_llr ( hierarch_module );
mca_coll_hierarch_get_all_lleaders ( rank, hierarch_module, llead, 1 );
/* Generate the lleader communicator assuming that all lleaders are the first
process in the list of processes with the same color. A function generating
other lleader-comms will follow soon. */
color = MPI_UNDEFINED;
if ( llead->am_lleader ) {
color = 1;
}
ret = ompi_comm_split ( comm, color, rank, &llcomm, 0);
if ( OMPI_SUCCESS != ret ) {
goto exit;
}
if ( OMPI_COMM_CID_IS_LOWER ( llcomm, comm ) ) {
/* Mark the communicator as 'extra retain' and increase the
reference count by one more. See ompi_comm_activate
for detailed explanation.
*/
OMPI_COMM_SET_EXTRA_RETAIN (llcomm);
OBJ_RETAIN(llcomm);
}
llead->llcomm = llcomm;
/* Store it now on the data structure */
OBJ_CONSTRUCT(&(hierarch_module->hier_llead), opal_pointer_array_t);
opal_pointer_array_add ( &(hierarch_module->hier_llead), llead);
if ( mca_coll_hierarch_verbose_param ) {
mca_coll_hierarch_dump_struct (hierarch_module);
}
exit:
if ( OMPI_SUCCESS != ret ) {
if (NULL != llead) {
free(llead);
}
ompi_comm_free ( &lcomm );
return OMPI_ERROR;
}
return OMPI_SUCCESS;
}
