/* This routine is for a thread to yield control when the thread is waiting for
* the completion of communication inside a ROMIO routine but the progress
* engine is blocked by another thread. */
void MPIR_Ext_cs_yield(void)
{
/* TODO: check whether the progress engine is blocked */
MPID_THREAD_CS_YIELD(GLOBAL, MPIR_THREAD_GLOBAL_ALLFUNC_MUTEX);
}
int MPIR_Get_contextid_sparse_group(MPIR_Comm * comm_ptr, MPIR_Group * group_ptr, int tag,
MPIR_Context_id_t * context_id, int ignore_id)
{
int mpi_errno = MPI_SUCCESS;
MPIR_Errflag_t errflag = MPIR_ERR_NONE;
struct gcn_state st;
struct gcn_state *tmp;
MPIR_FUNC_TERSE_STATE_DECL(MPID_STATE_MPIR_GET_CONTEXTID);
MPIR_FUNC_TERSE_ENTER(MPID_STATE_MPIR_GET_CONTEXTID);
st.first_iter = 1;
st.comm_ptr = comm_ptr;
st.tag = tag;
st.own_mask = 0;
st.own_eager_mask = 0;
/* Group-collective and ignore_id should never be combined */
MPIR_Assert(!(group_ptr != NULL && ignore_id));
*context_id = 0;
MPL_DBG_MSG_FMT(MPIR_DBG_COMM, VERBOSE, (MPL_DBG_FDEST,
"Entering; shared state is %d:%d, my ctx id is %d, tag=%d",
mask_in_use, eager_in_use, comm_ptr->context_id, tag));
while (*context_id == 0) {
/* We lock only around access to the mask (except in the global locking
* case). If another thread is using the mask, we take a mask of zero. */
MPID_THREAD_CS_ENTER(POBJ, MPIR_THREAD_POBJ_CTX_MUTEX);
if (initialize_context_mask) {
context_id_init();
}
if (eager_nelem < 0) {
/* Ensure that at least one word of deadlock-free context IDs is
* always set aside for the base protocol */
MPIR_Assert(MPIR_CVAR_CTXID_EAGER_SIZE >= 0 &&
MPIR_CVAR_CTXID_EAGER_SIZE < MPIR_MAX_CONTEXT_MASK - 1);
eager_nelem = MPIR_CVAR_CTXID_EAGER_SIZE;
}
if (ignore_id) {
/* We are not participating in the resulting communicator, so our
* context ID space doesn't matter. Set the mask to "all available". */
memset(st.local_mask, 0xff, MPIR_MAX_CONTEXT_MASK * sizeof(int));
st.own_mask = 0;
/* don't need to touch mask_in_use/lowest_context_id b/c our thread
* doesn't ever need to "win" the mask */
}
/* Deadlock avoidance: Only participate in context id loop when all
* processes have called this routine. On the first iteration, use the
* "eager" allocation protocol.
*/
else if (st.first_iter) {
memset(st.local_mask, 0, MPIR_MAX_CONTEXT_MASK * sizeof(int));
st.own_eager_mask = 0;
/* Attempt to reserve the eager mask segment */
if (!eager_in_use && eager_nelem > 0) {
int i;
for (i = 0; i < eager_nelem; i++)
st.local_mask[i] = context_mask[i];
eager_in_use = 1;
st.own_eager_mask = 1;
}
}
else {
MPIR_Assert(next_gcn != NULL);
/*If we are here, at least one element must be in the list, at least myself */
/* only the first element in the list can own the mask. However, maybe the mask is used
* by another thread, which added another allcoation to the list bevore. So we have to check,
* if the mask is used and mark, if we own it */
if (mask_in_use || &st != next_gcn) {
memset(st.local_mask, 0, MPIR_MAX_CONTEXT_MASK * sizeof(int));
st.own_mask = 0;
MPL_DBG_MSG_FMT(MPIR_DBG_COMM, VERBOSE, (MPL_DBG_FDEST,
"Mask is in use, my context_id is %d, owner context id is %d",
st.comm_ptr->context_id,
next_gcn->comm_ptr->context_id));
}
else {
int i;
/* Copy safe mask segment to local_mask */
for (i = 0; i < eager_nelem; i++)
st.local_mask[i] = 0;
for (i = eager_nelem; i < MPIR_MAX_CONTEXT_MASK; i++)
st.local_mask[i] = context_mask[i];
mask_in_use = 1;
st.own_mask = 1;
MPL_DBG_MSG(MPIR_DBG_COMM, VERBOSE, "Copied local_mask");
}
}
MPID_THREAD_CS_EXIT(POBJ, MPIR_THREAD_POBJ_CTX_MUTEX);
/* Note: MPIR_MAX_CONTEXT_MASK elements of local_mask are used by the
* context ID allocation algorithm. The additional element is ignored
* by the context ID mask access routines and is used as a flag for
* detecting context ID exhaustion (explained below). */
if (st.own_mask || ignore_id)
st.local_mask[ALL_OWN_MASK_FLAG] = 1;
else
st.local_mask[ALL_OWN_MASK_FLAG] = 0;
/* Now, try to get a context id */
MPIR_Assert(comm_ptr->comm_kind == MPIR_COMM_KIND__INTRACOMM);
/* In the global and brief-global cases, note that this routine will
* release that global lock when it needs to wait. That will allow
* other processes to enter the global or brief global critical section.
*/
if (group_ptr != NULL) {
int coll_tag = tag | MPIR_Process.tagged_coll_mask; /* Shift tag into the tagged coll space */
mpi_errno = MPIR_Allreduce_group(MPI_IN_PLACE, st.local_mask, MPIR_MAX_CONTEXT_MASK + 1,
MPI_INT, MPI_BAND, comm_ptr, group_ptr, coll_tag,
&errflag);
}
else {
mpi_errno = MPID_Allreduce(MPI_IN_PLACE, st.local_mask, MPIR_MAX_CONTEXT_MASK + 1,
MPI_INT, MPI_BAND, comm_ptr, &errflag);
}
if (mpi_errno)
MPIR_ERR_POP(mpi_errno);
MPIR_ERR_CHKANDJUMP(errflag, mpi_errno, MPI_ERR_OTHER, "**coll_fail");
/* MT FIXME 2/3 cases don't seem to need the CONTEXTID CS, check and
* narrow this region */
MPID_THREAD_CS_ENTER(POBJ, MPIR_THREAD_POBJ_CTX_MUTEX);
if (ignore_id) {
/* we don't care what the value was, but make sure that everyone
* who did care agreed on a value */
*context_id = locate_context_bit(st.local_mask);
/* used later in out-of-context ids check and outer while loop condition */
}
else if (st.own_eager_mask) {
/* There is a chance that we've found a context id */
/* Find_and_allocate_context_id updates the context_mask if it finds a match */
*context_id = find_and_allocate_context_id(st.local_mask);
MPL_DBG_MSG_D(MPIR_DBG_COMM, VERBOSE, "Context id is now %hd", *context_id);
st.own_eager_mask = 0;
eager_in_use = 0;
if (*context_id <= 0) {
/* else we did not find a context id. Give up the mask in case
* there is another thread (with a lower input context id)
* waiting for it. We need to ensure that any other threads
* have the opportunity to run, hence yielding */
/* FIXME: Do we need to do an GLOBAL yield here?
* When we do a collective operation, we anyway yield
* for other others */
MPID_THREAD_CS_YIELD(GLOBAL, MPIR_THREAD_GLOBAL_ALLFUNC_MUTEX);
MPID_THREAD_CS_YIELD(POBJ, MPIR_THREAD_POBJ_CTX_MUTEX);
}
}
else if (st.own_mask) {
/* There is a chance that we've found a context id */
/* Find_and_allocate_context_id updates the context_mask if it finds a match */
*context_id = find_and_allocate_context_id(st.local_mask);
MPL_DBG_MSG_D(MPIR_DBG_COMM, VERBOSE, "Context id is now %hd", *context_id);
mask_in_use = 0;
if (*context_id > 0) {
/* If we found a new context id, we have to remove the element from the list, so the
* next allocation can own the mask */
if (next_gcn == &st) {
next_gcn = st.next;
}
else {
for (tmp = next_gcn; tmp->next != &st; tmp = tmp->next); /* avoid compiler warnings */
tmp->next = st.next;
}
}
else {
/* else we did not find a context id. Give up the mask in case
* there is another thread in the gcn_next_list
* waiting for it. We need to ensure that any other threads
* have the opportunity to run, hence yielding */
/* FIXME: Do we need to do an GLOBAL yield here?
* When we do a collective operation, we anyway yield
* for other others */
MPID_THREAD_CS_YIELD(GLOBAL, MPIR_THREAD_GLOBAL_ALLFUNC_MUTEX);
MPID_THREAD_CS_YIELD(POBJ, MPIR_THREAD_POBJ_CTX_MUTEX);
}
}
else {
/* As above, force this thread to yield */
/* FIXME: Do we need to do an GLOBAL yield here? When we
* do a collective operation, we anyway yield for other
* others */
MPID_THREAD_CS_YIELD(GLOBAL, MPIR_THREAD_GLOBAL_ALLFUNC_MUTEX);
MPID_THREAD_CS_YIELD(POBJ, MPIR_THREAD_POBJ_CTX_MUTEX);
}
MPID_THREAD_CS_EXIT(POBJ, MPIR_THREAD_POBJ_CTX_MUTEX);
/* Test for context ID exhaustion: All threads that will participate in
* the new communicator owned the mask and could not allocate a context
* ID. This indicates that either some process has no context IDs
* available, or that some are available, but the allocation cannot
* succeed because there is no common context ID. */
if (*context_id == 0 && st.local_mask[ALL_OWN_MASK_FLAG] == 1) {
/* --BEGIN ERROR HANDLING-- */
int nfree = 0;
int ntotal = 0;
int minfree;
if (st.own_mask) {
MPID_THREAD_CS_ENTER(POBJ, MPIR_THREAD_POBJ_CTX_MUTEX);
mask_in_use = 0;
MPID_THREAD_CS_EXIT(POBJ, MPIR_THREAD_POBJ_CTX_MUTEX);
}
context_mask_stats(&nfree, &ntotal);
if (ignore_id)
minfree = INT_MAX;
else
minfree = nfree;
if (group_ptr != NULL) {
int coll_tag = tag | MPIR_Process.tagged_coll_mask; /* Shift tag into the tagged coll space */
mpi_errno = MPIR_Allreduce_group(MPI_IN_PLACE, &minfree, 1, MPI_INT, MPI_MIN,
comm_ptr, group_ptr, coll_tag, &errflag);
}
else {
mpi_errno = MPID_Allreduce(MPI_IN_PLACE, &minfree, 1, MPI_INT,
MPI_MIN, comm_ptr, &errflag);
}
if (minfree > 0) {
MPIR_ERR_SETANDJUMP3(mpi_errno, MPI_ERR_OTHER,
"**toomanycommfrag", "**toomanycommfrag %d %d %d",
nfree, ntotal, ignore_id);
}
else {
MPIR_ERR_SETANDJUMP3(mpi_errno, MPI_ERR_OTHER,
"**toomanycomm", "**toomanycomm %d %d %d",
nfree, ntotal, ignore_id);
}
/* --END ERROR HANDLING-- */
}
if (st.first_iter == 1) {
st.first_iter = 0;
/* to avoid deadlocks, the element is not added to the list bevore the first iteration */
if (!ignore_id && *context_id == 0) {
MPID_THREAD_CS_ENTER(POBJ, MPIR_THREAD_POBJ_CTX_MUTEX);
add_gcn_to_list(&st);
MPID_THREAD_CS_EXIT(POBJ, MPIR_THREAD_POBJ_CTX_MUTEX);
}
}
}
fn_exit:
if (ignore_id)
*context_id = MPIR_INVALID_CONTEXT_ID;
MPL_DBG_MSG_S(MPIR_DBG_COMM, VERBOSE, "Context mask = %s", context_mask_to_str());
MPIR_FUNC_TERSE_EXIT(MPID_STATE_MPIR_GET_CONTEXTID);
return mpi_errno;
/* --BEGIN ERROR HANDLING-- */
fn_fail:
/* Release the masks */
MPID_THREAD_CS_ENTER(POBJ, MPIR_THREAD_POBJ_CTX_MUTEX);
if (st.own_mask) {
mask_in_use = 0;
}
/*If in list, remove it */
if (!st.first_iter && !ignore_id) {
if (next_gcn == &st) {
next_gcn = st.next;
}
else {
for (tmp = next_gcn; tmp->next != &st; tmp = tmp->next);
tmp->next = st.next;
}
}
MPID_THREAD_CS_EXIT(POBJ, MPIR_THREAD_POBJ_CTX_MUTEX);
goto fn_exit;
/* --END ERROR HANDLING-- */
}
int MPID_Mprobe(int source, int tag, MPID_Comm *comm, int context_offset,
MPID_Request **message, MPI_Status *status)
{
int mpi_errno = MPI_SUCCESS;
MPID_Progress_state progress_state;
int found = FALSE;
int context_id = comm->recvcontext_id + context_offset;
*message = NULL;
if (source == MPI_PROC_NULL)
{
MPIR_Status_set_procnull(status);
found = TRUE;
*message = NULL; /* should be interpreted as MPI_MESSAGE_NO_PROC */
goto fn_exit;
}
/* Check to make sure the communicator hasn't already been revoked */
if (comm->revoked) {
MPIR_ERR_SETANDJUMP(mpi_errno,MPIX_ERR_REVOKED,"**revoked");
}
#ifdef ENABLE_COMM_OVERRIDES
if (MPIDI_Anysource_improbe_fn) {
if (source == MPI_ANY_SOURCE) {
/* if it's anysource, loop while checking the shm recv
queue and improbing the netmod, then do a progress
test to make some progress. */
do {
MPID_THREAD_CS_ENTER(POBJ, MPIR_THREAD_MSGQ_MUTEX);
*message = MPIDI_CH3U_Recvq_FDU_matchonly(source, tag, context_id, comm,&found);
MPID_THREAD_CS_EXIT(POBJ, MPIR_THREAD_MSGQ_MUTEX);
if (found) goto fn_exit;
mpi_errno = MPIDI_Anysource_improbe_fn(tag, comm, context_offset, &found, message, status);
if (mpi_errno) MPIR_ERR_POP(mpi_errno);
if (found) goto fn_exit;
MPID_THREAD_CS_YIELD(GLOBAL, MPIR_THREAD_GLOBAL_ALLFUNC_MUTEX);
/* FIXME could this be replaced with a progress_wait? */
mpi_errno = MPIDI_CH3_Progress_test();
if (mpi_errno) MPIR_ERR_POP(mpi_errno);
} while (1);
}
else {
/* it's not anysource, see if this is for the netmod */
MPIDI_VC_t * vc;
MPIDI_Comm_get_vc_set_active(comm, source, &vc);
if (vc->comm_ops && vc->comm_ops->improbe) {
/* netmod has overridden improbe */
do {
mpi_errno = vc->comm_ops->improbe(vc, source, tag, comm, context_offset, &found,
message, status);
if (mpi_errno) MPIR_ERR_POP(mpi_errno);
if (found) goto fn_exit;
MPID_THREAD_CS_YIELD(GLOBAL, MPIR_THREAD_GLOBAL_ALLFUNC_MUTEX);
/* FIXME could this be replaced with a progress_wait? */
mpi_errno = MPIDI_CH3_Progress_test();
if (mpi_errno) MPIR_ERR_POP(mpi_errno);
} while (1);
}
/* fall-through to shm case */
}
}
#endif
/* Inefficient implementation: we poll the unexpected queue looking for a
* matching request, interleaved with calls to progress. If there are many
* non-matching unexpected messages in the queue then we will end up
* needlessly scanning the UQ.
*
* A smarter implementation would enqueue a partial request (one lacking the
* recv buffer triple) onto the PQ. Unfortunately, this is a lot harder to
* do than it seems at first because of the spread-out nature of callers to
* various CH3U_Recvq routines and especially because of the enqueue/dequeue
* hooks for native MX tag matching support. */
MPIDI_CH3_Progress_start(&progress_state);
do
{
MPID_THREAD_CS_ENTER(POBJ, MPIR_THREAD_MSGQ_MUTEX);
*message = MPIDI_CH3U_Recvq_FDU_matchonly(source, tag, context_id, comm, &found);
MPID_THREAD_CS_EXIT(POBJ, MPIR_THREAD_MSGQ_MUTEX);
if (found)
break;
mpi_errno = MPIDI_CH3_Progress_wait(&progress_state);
}
while(mpi_errno == MPI_SUCCESS);
MPIDI_CH3_Progress_end(&progress_state);
if (mpi_errno) MPIR_ERR_POP(mpi_errno);
if (*message) {
(*message)->kind = MPID_REQUEST_MPROBE;
MPIR_Request_extract_status((*message), status);
}
fn_exit:
return mpi_errno;
fn_fail:
goto fn_exit;
}
