Beispiel #1
0
int MPID_Send(const void * buf, MPI_Aint count, MPI_Datatype datatype, int rank,
	      int tag, MPID_Comm * comm, int context_offset,
	      MPID_Request ** request)
{
    MPIDI_msg_sz_t data_sz;
    int dt_contig;
    MPI_Aint dt_true_lb;
    MPID_Datatype * dt_ptr;
    MPID_Request * sreq = NULL;
    MPIDI_VC_t * vc;
#if defined(MPID_USE_SEQUENCE_NUMBERS)
    MPID_Seqnum_t seqnum;
#endif    
    int eager_threshold = -1;
    int mpi_errno = MPI_SUCCESS;    
#if defined(FINEGRAIN_MPI)
    int destpid=-1, destworldrank=-1;
#endif
    MPIDI_STATE_DECL(MPID_STATE_MPID_SEND);

    MPIDI_FUNC_ENTER(MPID_STATE_MPID_SEND);

    MPIU_DBG_MSG_FMT(CH3_OTHER,VERBOSE,(MPIU_DBG_FDEST,
                "rank=%d, tag=%d, context=%d", 
		rank, tag, comm->context_id + context_offset));

    /* Check to make sure the communicator hasn't already been revoked */
    if (comm->revoked &&
            MPIR_AGREE_TAG != MPIR_TAG_MASK_ERROR_BITS(tag & ~MPIR_Process.tagged_coll_mask) &&
            MPIR_SHRINK_TAG != MPIR_TAG_MASK_ERROR_BITS(tag & ~MPIR_Process.tagged_coll_mask)) {
        MPIR_ERR_SETANDJUMP(mpi_errno,MPIX_ERR_REVOKED,"**revoked");
    }

#if defined(FINEGRAIN_MPI)
    MPIDI_Comm_get_pid_worldrank(comm, rank, &destpid, &destworldrank);

    if (COMPARE_RANKS(rank,comm,destpid) && comm->comm_kind != MPID_INTERCOMM)
    {
	mpi_errno = MPIDI_Isend_self(&buf, count, datatype, rank, tag, comm,
				     context_offset, MPIDI_REQUEST_TYPE_SEND,
				     &sreq);
        if (rank == comm->rank)
	{
            printf("my_fgrank=%d: %s, self send DEADLOCK\n", my_fgrank, __FUNCTION__);
	    if (sreq != NULL && sreq->cc != 0) {
		MPIR_ERR_SETANDJUMP(mpi_errno,MPI_ERR_OTHER,
				    "**dev|selfsenddeadlock");
	    }
	}

#else
    if (rank == comm->rank && comm->comm_kind != MPID_INTERCOMM)
    {
	mpi_errno = MPIDI_Isend_self(buf, count, datatype, rank, tag, comm, 
				     context_offset, MPIDI_REQUEST_TYPE_SEND, 
				     &sreq);

	/* In the single threaded case, sending to yourself will cause 
	   deadlock.  Note that in the runtime-thread case, this check
	   will not be made (long-term FIXME) */
#       ifndef MPICH_IS_THREADED
	{
	    if (sreq != NULL && MPID_cc_get(sreq->cc) != 0) {
		MPIR_ERR_SETANDJUMP(mpi_errno,MPI_ERR_OTHER,
				    "**dev|selfsenddeadlock");
	    }
	}
#	endif
#endif
	if (mpi_errno != MPI_SUCCESS) { MPIR_ERR_POP(mpi_errno); }
	goto fn_exit;
    }

    if (rank == MPI_PROC_NULL)
    {
	goto fn_exit;
    }

#if defined(FINEGRAIN_MPI)
    MPIDI_Comm_get_vc_set_active_direct(comm, destpid, &vc);
#else
    MPIDI_Comm_get_vc_set_active(comm, rank, &vc);
#endif
    MPIR_ERR_CHKANDJUMP1(vc->state == MPIDI_VC_STATE_MORIBUND, mpi_errno, MPIX_ERR_PROC_FAILED, "**comm_fail", "**comm_fail %d", rank);

#ifdef ENABLE_COMM_OVERRIDES
    if (vc->comm_ops && vc->comm_ops->send)
    {
	mpi_errno = vc->comm_ops->send( vc, buf, count, datatype, rank, tag, comm, context_offset, &sreq);
	goto fn_exit;
    }
#endif

    MPIDI_Datatype_get_info(count, datatype, dt_contig, data_sz, dt_ptr, 
			    dt_true_lb);


    if (data_sz == 0)
    {
	MPIDI_CH3_Pkt_t upkt;
	MPIDI_CH3_Pkt_eager_send_t * const eager_pkt = &upkt.eager_send;

	MPIU_DBG_MSG(CH3_OTHER,VERBOSE,"sending zero length message");
	MPIDI_Pkt_init(eager_pkt, MPIDI_CH3_PKT_EAGER_SEND);
#if defined(FINEGRAIN_MPI)
        eager_pkt->match.parts.dest_rank = destworldrank;
#endif
	eager_pkt->match.parts.rank = comm->rank;
	eager_pkt->match.parts.tag = tag;
	eager_pkt->match.parts.context_id = comm->context_id + context_offset;
	eager_pkt->sender_req_id = MPI_REQUEST_NULL;
	eager_pkt->data_sz = 0;
	
	MPIDI_VC_FAI_send_seqnum(vc, seqnum);
	MPIDI_Pkt_set_seqnum(eager_pkt, seqnum);
	
	MPID_THREAD_CS_ENTER(POBJ, vc->pobj_mutex);
	mpi_errno = MPIDI_CH3_iStartMsg(vc, eager_pkt, sizeof(*eager_pkt), &sreq);
	MPID_THREAD_CS_EXIT(POBJ, vc->pobj_mutex);
	/* --BEGIN ERROR HANDLING-- */
	if (mpi_errno != MPI_SUCCESS)
	{
	    MPIR_ERR_SETANDJUMP(mpi_errno,MPI_ERR_OTHER,"**ch3|eagermsg");
	}
	/* --END ERROR HANDLING-- */
	if (sreq != NULL)
	{
	    MPIDI_Request_set_seqnum(sreq, seqnum);
	    MPIDI_Request_set_type(sreq, MPIDI_REQUEST_TYPE_SEND);
	    /* sreq->comm = comm;
	      MPIR_Comm_add_ref(comm); -- not necessary for blocking functions */
	}
	
	goto fn_exit;
    }

    MPIDI_CH3_GET_EAGER_THRESHOLD(&eager_threshold, comm, vc);

    /* FIXME: flow control: limit number of outstanding eager messages
       containing data and need to be buffered by the receiver */
#ifdef USE_EAGER_SHORT
    if (dt_contig && data_sz <= MPIDI_EAGER_SHORT_SIZE) {
	mpi_errno = MPIDI_CH3_EagerContigShortSend( &sreq, 
					       MPIDI_CH3_PKT_EAGERSHORT_SEND,
					       (char *)buf + dt_true_lb,
					       data_sz, rank, tag, comm, 
					       context_offset );
    }
    else
#endif

    if (data_sz + sizeof(MPIDI_CH3_Pkt_eager_send_t) <= eager_threshold)
    {
	if (dt_contig)
        {
 	    mpi_errno = MPIDI_CH3_EagerContigSend( &sreq, 
						   MPIDI_CH3_PKT_EAGER_SEND,
						   (char *)buf + dt_true_lb,
						   data_sz, rank, tag, comm, 
						   context_offset );
	}
	else
        {
	    MPIDI_Request_create_sreq(sreq, mpi_errno, goto fn_exit);
	    MPIDI_Request_set_type(sreq, MPIDI_REQUEST_TYPE_SEND);
	    mpi_errno = MPIDI_CH3_EagerNoncontigSend( &sreq, 
                                                      MPIDI_CH3_PKT_EAGER_SEND,
                                                      buf, count, datatype,
                                                      data_sz, rank, tag, 
                                                      comm, context_offset );
	}
    }
    else
    {
Beispiel #2
0
int MPID_Isend(const void * buf, int count, MPI_Datatype datatype, int rank, 
	       int tag, MPID_Comm * comm, int context_offset,
               MPID_Request ** request)
{
    MPIDI_msg_sz_t data_sz;
    int dt_contig;
    MPI_Aint dt_true_lb;
    MPID_Datatype * dt_ptr;
    MPID_Request * sreq;
    MPIDI_VC_t * vc=0;
#if defined(MPID_USE_SEQUENCE_NUMBERS)
    MPID_Seqnum_t seqnum;
#endif    
    int mpi_errno = MPI_SUCCESS;
    MPIDI_STATE_DECL(MPID_STATE_MPID_ISEND);

    MPIDI_FUNC_ENTER(MPID_STATE_MPID_ISEND);

    MPIU_DBG_MSG_FMT(CH3_OTHER,VERBOSE,(MPIU_DBG_FDEST,
                  "rank=%d, tag=%d, context=%d", 
                  rank, tag, comm->context_id + context_offset));
    
    if (rank == comm->rank && comm->comm_kind != MPID_INTERCOMM)
    {
#if defined (_OSU_PSM_)
        goto skip_self_send; /* psm will internally do self-send, no special
                                handling is needed here */
#endif /* _OSU_PSM_ */          
	mpi_errno = MPIDI_Isend_self(buf, count, datatype, rank, tag, comm, 
			    context_offset, MPIDI_REQUEST_TYPE_SEND, &sreq);
	goto fn_exit;
    }
#if defined (_OSU_PSM_)
skip_self_send:
#endif

    if (rank != MPI_PROC_NULL) {
        MPIDI_Comm_get_vc_set_active(comm, rank, &vc);
#ifdef ENABLE_COMM_OVERRIDES
        /* this needs to come before the sreq is created, since the override
         * function is responsible for creating its own request */
        if (vc->comm_ops && vc->comm_ops->isend)
        {
            mpi_errno = vc->comm_ops->isend( vc, buf, count, datatype, rank, tag, comm, context_offset, &sreq);
            goto fn_exit;
        }
#endif
    }

    MPIDI_Request_create_sreq(sreq, mpi_errno, goto fn_exit);
    MPIDI_Request_set_type(sreq, MPIDI_REQUEST_TYPE_SEND);

    if (rank == MPI_PROC_NULL)
    {
	MPIU_Object_set_ref(sreq, 1);
        MPID_cc_set(&sreq->cc, 0);
	goto fn_exit;
    }

    MPIDI_Datatype_get_info(count, datatype, dt_contig, data_sz, dt_ptr, 
			    dt_true_lb);
    
    if (data_sz == 0)
    {
#if defined (_OSU_PSM_)
        goto eager_send;
#endif /* _OSU_PSM_ */
	MPIDI_CH3_Pkt_t upkt;
	MPIDI_CH3_Pkt_eager_send_t * const eager_pkt = &upkt.eager_send;

	MPIDI_Request_set_msg_type(sreq, MPIDI_REQUEST_EAGER_MSG);
	sreq->dev.OnDataAvail = 0;
	    
	MPIU_DBG_MSG(CH3_OTHER,VERBOSE,"sending zero length message");
	MPIDI_Pkt_init(eager_pkt, MPIDI_CH3_PKT_EAGER_SEND);
	eager_pkt->match.parts.rank = comm->rank;
	eager_pkt->match.parts.tag = tag;
	eager_pkt->match.parts.context_id = comm->context_id + context_offset;
	eager_pkt->sender_req_id = sreq->handle;
	eager_pkt->data_sz = 0;
	
	MPIDI_VC_FAI_send_seqnum(vc, seqnum);
	MPIDI_Pkt_set_seqnum(eager_pkt, seqnum);
	MPIDI_Request_set_seqnum(sreq, seqnum);
	
	MPIU_THREAD_CS_ENTER(CH3COMM,vc);
	mpi_errno = MPIU_CALL(MPIDI_CH3,iSend(vc, sreq, eager_pkt, 
					      sizeof(*eager_pkt)));
	MPIU_THREAD_CS_EXIT(CH3COMM,vc);
	/* --BEGIN ERROR HANDLING-- */
	if (mpi_errno != MPI_SUCCESS)
	{
	    MPIU_Object_set_ref(sreq, 0);
	    MPIDI_CH3_Request_destroy(sreq);
	    sreq = NULL;
            MPIU_ERR_SET(mpi_errno, MPI_ERR_OTHER, "**ch3|eagermsg");
	    goto fn_exit;
	}
	/* --END ERROR HANDLING-- */

	goto fn_exit;
    }

#if defined (_OSU_PSM_)
    if(HANDLE_GET_KIND(datatype) != HANDLE_KIND_BUILTIN) {
        sreq->dev.datatype_ptr = dt_ptr;
        MPID_Datatype_add_ref(dt_ptr);
        sreq->psm_flags |= PSM_NEED_DTYPE_RELEASE;
    }
    if(vc->force_eager)
        goto eager_send;
#endif /* _OSU_PSM_ */

#if defined(_OSU_MVAPICH_)
    int i;
    for (i = 0 ; i < rdma_num_extra_polls; i++)
    {
        if (rdma_global_ext_sendq_size > 1)
            MPID_Progress_test();
    }
#endif
    /* FIXME: flow control: limit number of outstanding eager messsages 
       containing data and need to be buffered by the receiver */
#if defined(_OSU_MVAPICH_)
    if (data_sz + sizeof(MPIDI_CH3_Pkt_eager_send_t) <=	vc->eager_max_msg_sz
        && !vc->force_rndv)
#else /* defined(_OSU_MVAPICH_) */
    if (data_sz + sizeof(MPIDI_CH3_Pkt_eager_send_t) <=	vc->eager_max_msg_sz)
#endif /* defined(_OSU_MVAPICH_) */
    {
#if defined (_OSU_PSM_)
eager_send:
#endif /* _OSU_PSM */
        if (dt_contig) 
        {
            mpi_errno = MPIDI_CH3_EagerContigIsend( &sreq, 
                                MPIDI_CH3_PKT_EAGER_SEND,
                                (char*)buf + dt_true_lb, 
                                data_sz, rank, tag, 
                                comm, context_offset );
        } 
        else 
        {
#if defined (_OSU_PSM_)
            sreq->psm_flags |= PSM_NON_BLOCKING_SEND;
#endif
            mpi_errno = MPIDI_CH3_EagerNoncontigSend( &sreq, 
                                                          MPIDI_CH3_PKT_EAGER_SEND,
                                                          buf, count, datatype,
                                                          data_sz, rank, tag, 
                                                          comm, context_offset );
#if defined (_OSU_PSM_)
            goto fn_exit;
#endif            
            /* If we're not complete, then add a reference to the datatype */
            if (sreq && sreq->dev.OnDataAvail) {
                sreq->dev.datatype_ptr = dt_ptr;
                MPID_Datatype_add_ref(dt_ptr);
            }
        }
    }
    else
    {
	/* Note that the sreq was created above */
	MPIDI_Request_set_msg_type( sreq, MPIDI_REQUEST_RNDV_MSG );
	mpi_errno = vc->rndvSend_fn( &sreq, buf, count, datatype, dt_contig,
                                     data_sz, dt_true_lb, rank, tag, comm, 
                                     context_offset );
	/* FIXME: fill temporary IOV or pack temporary buffer after send to 
	   hide some latency.  This requires synchronization
           because the CTS packet could arrive and be processed before the 
	   above iStartmsg completes (depending on the progress
           engine, threads, etc.). */
#if defined(_OSU_MVAPICH_)
        /* rndv transfers need to process CTS packet to initiate the actual RDMA transfer */
        MPID_Progress_test();
#endif /* defined(_OSU_MVAPICH_) */
	
	if (sreq && dt_ptr != NULL)
	{
	    sreq->dev.datatype_ptr = dt_ptr;
	    MPID_Datatype_add_ref(dt_ptr);
	}
    }

  fn_exit:
    *request = sreq;

#if defined(_OSU_MVAPICH_)
    for (i = 0 ; i < rdma_num_extra_polls; i++)
    {
        if (rdma_global_ext_sendq_size > 1)
            MPID_Progress_test();
    }
#endif

    MPIU_DBG_STMT(CH3_OTHER,VERBOSE,
    {
	if (sreq != NULL)
	{
	    MPIU_DBG_MSG_P(CH3_OTHER,VERBOSE,"request allocated, handle=0x%08x", sreq->handle);
	}
    }
		  );
Beispiel #3
0
int MPID_Irsend(const void * buf, int count, MPI_Datatype datatype, int rank, int tag, MPID_Comm * comm, int context_offset,
		MPID_Request ** request)
{
    MPIDI_CH3_Pkt_t upkt;
    MPIDI_CH3_Pkt_ready_send_t * const ready_pkt = &upkt.ready_send;
    MPIDI_msg_sz_t data_sz;
    int dt_contig;
    MPI_Aint dt_true_lb;
    MPID_Datatype * dt_ptr;
    MPID_Request * sreq;
    MPIDI_VC_t * vc;
#if defined(MPID_USE_SEQUENCE_NUMBERS)
    MPID_Seqnum_t seqnum;
#endif    
    int mpi_errno = MPI_SUCCESS;    
    MPIDI_STATE_DECL(MPID_STATE_MPID_IRSEND);

    MPIDI_FUNC_ENTER(MPID_STATE_MPID_IRSEND);

    MPIU_DBG_MSG_FMT(CH3_OTHER,VERBOSE,(MPIU_DBG_FDEST,
                "rank=%d, tag=%d, context=%d", 
                rank, tag, comm->context_id + context_offset));

    /* Check to make sure the communicator hasn't already been revoked */
    if (comm->revoked &&
            MPIR_AGREE_TAG != MPIR_TAG_MASK_ERROR_BITS(tag & ~MPIR_Process.tagged_coll_mask) &&
            MPIR_SHRINK_TAG != MPIR_TAG_MASK_ERROR_BITS(tag & ~MPIR_Process.tagged_coll_mask)) {
        MPIR_ERR_SETANDJUMP(mpi_errno,MPIX_ERR_REVOKED,"**revoked");
    }
    
    if (rank == comm->rank && comm->comm_kind != MPID_INTERCOMM)
    {
	mpi_errno = MPIDI_Isend_self(buf, count, datatype, rank, tag, comm, context_offset, MPIDI_REQUEST_TYPE_RSEND, &sreq);
	goto fn_exit;
    }

    if (rank != MPI_PROC_NULL) {
        MPIDI_Comm_get_vc_set_active(comm, rank, &vc);
#ifdef ENABLE_COMM_OVERRIDES
        /* this needs to come before the sreq is created, since the override
         * function is responsible for creating its own request */
        if (vc->comm_ops && vc->comm_ops->irsend)
        {
            mpi_errno = vc->comm_ops->irsend( vc, buf, count, datatype, rank, tag, comm, context_offset, &sreq);
            goto fn_exit;
        }
#endif
    }
    
    MPIDI_Request_create_sreq(sreq, mpi_errno, goto fn_exit);
    MPIDI_Request_set_type(sreq, MPIDI_REQUEST_TYPE_RSEND);
    MPIDI_Request_set_msg_type(sreq, MPIDI_REQUEST_EAGER_MSG);
    
    if (rank == MPI_PROC_NULL)
    {
	MPIU_Object_set_ref(sreq, 1);
        MPID_cc_set(&sreq->cc, 0);
	goto fn_exit;
    }
    
    MPIDI_Datatype_get_info(count, datatype, dt_contig, data_sz, dt_ptr, dt_true_lb);

    MPIDI_Pkt_init(ready_pkt, MPIDI_CH3_PKT_READY_SEND);
    ready_pkt->match.parts.rank = comm->rank;
    ready_pkt->match.parts.tag = tag;
    ready_pkt->match.parts.context_id = comm->context_id + context_offset;
    ready_pkt->sender_req_id = MPI_REQUEST_NULL;
    ready_pkt->data_sz = data_sz;

    if (data_sz == 0)
    {
	MPIU_DBG_MSG(CH3_OTHER,VERBOSE,"sending zero length message");

	sreq->dev.OnDataAvail = 0;
	
	MPIDI_VC_FAI_send_seqnum(vc, seqnum);
	MPIDI_Pkt_set_seqnum(ready_pkt, seqnum);
	MPIDI_Request_set_seqnum(sreq, seqnum);
	
	MPID_THREAD_CS_ENTER(POBJ, vc->pobj_mutex);
	mpi_errno = MPIDI_CH3_iSend(vc, sreq, ready_pkt, sizeof(*ready_pkt));
	MPID_THREAD_CS_EXIT(POBJ, vc->pobj_mutex);
	/* --BEGIN ERROR HANDLING-- */
	if (mpi_errno != MPI_SUCCESS)
	{
            MPID_Request_release(sreq);
	    sreq = NULL;
            MPIR_ERR_SET(mpi_errno, MPI_ERR_OTHER, "**ch3|eagermsg");
	    goto fn_exit;
	}
	/* --END ERROR HANDLING-- */
	goto fn_exit;
    }
    
    if (vc->ready_eager_max_msg_sz < 0 || data_sz + sizeof(MPIDI_CH3_Pkt_ready_send_t) <= vc->ready_eager_max_msg_sz) {
        if (dt_contig) {
            mpi_errno = MPIDI_CH3_EagerContigIsend( &sreq,
                                                    MPIDI_CH3_PKT_READY_SEND,
                                                    (char*)buf + dt_true_lb,
                                                    data_sz, rank, tag,
                                                    comm, context_offset );
            
        }
        else {
            mpi_errno = MPIDI_CH3_EagerNoncontigSend( &sreq,
                                                      MPIDI_CH3_PKT_READY_SEND,
                                                      buf, count, datatype,
                                                      data_sz, rank, tag,
                                                      comm, context_offset );
            /* If we're not complete, then add a reference to the datatype */
            if (sreq && sreq->dev.OnDataAvail) {
                sreq->dev.datatype_ptr = dt_ptr;
                MPID_Datatype_add_ref(dt_ptr);
            }
        }
    } else {
 	/* Do rendezvous.  This will be sent as a regular send not as
           a ready send, so the receiver won't know to send an error
           if the receive has not been posted */
	MPIDI_Request_set_msg_type( sreq, MPIDI_REQUEST_RNDV_MSG );
	mpi_errno = vc->rndvSend_fn( &sreq, buf, count, datatype, dt_contig,
                                     data_sz, dt_true_lb, rank, tag, comm,
                                     context_offset );
	if (sreq && dt_ptr != NULL) {
	    sreq->dev.datatype_ptr = dt_ptr;
	    MPID_Datatype_add_ref(dt_ptr);
	}
    }

  fn_exit:
    *request = sreq;

    MPIU_DBG_STMT(CH3_OTHER,VERBOSE,{
	if (sreq != NULL)
	{
	    MPIU_DBG_MSG_P(CH3_OTHER,VERBOSE,"request allocated, handle=0x%08x", sreq->handle);
	}
    }
		  );
Beispiel #4
0
int MPID_Send(const void * buf, int count, MPI_Datatype datatype, int rank, 
	      int tag, MPID_Comm * comm, int context_offset,
	      MPID_Request ** request)
{
    MPIDI_msg_sz_t data_sz;
    int dt_contig;
    MPI_Aint dt_true_lb;
    MPID_Datatype * dt_ptr;
    MPID_Request * sreq = NULL;
    MPIDI_VC_t * vc;
#if defined(MPID_USE_SEQUENCE_NUMBERS)
    MPID_Seqnum_t seqnum;
#endif    
    int mpi_errno = MPI_SUCCESS;    
    MPIDI_STATE_DECL(MPID_STATE_MPID_SEND);

    MPIDI_FUNC_ENTER(MPID_STATE_MPID_SEND);

    MPIU_DBG_MSG_FMT(CH3_OTHER,VERBOSE,(MPIU_DBG_FDEST,
                "rank=%d, tag=%d, context=%d", 
		rank, tag, comm->context_id + context_offset));

    if (rank == comm->rank && comm->comm_kind != MPID_INTERCOMM)
    {
	mpi_errno = MPIDI_Isend_self(buf, count, datatype, rank, tag, comm, 
				     context_offset, MPIDI_REQUEST_TYPE_SEND, 
				     &sreq);

	/* In the single threaded case, sending to yourself will cause 
	   deadlock.  Note that in the runtime-thread case, this check
	   will not be made (long-term FIXME) */
#       ifndef MPICH_IS_THREADED
	{
	    if (sreq != NULL && sreq->cc != 0) {
		MPIU_ERR_SETANDJUMP(mpi_errno,MPI_ERR_OTHER,
				    "**dev|selfsenddeadlock");
	    }
	}
#	endif
	if (mpi_errno != MPI_SUCCESS) { MPIU_ERR_POP(mpi_errno); }
	goto fn_exit;
    }

    if (rank == MPI_PROC_NULL)
    {
	goto fn_exit;
    }

    MPIDI_Comm_get_vc_set_active(comm, rank, &vc);

#ifdef ENABLE_COMM_OVERRIDES
    if (vc->comm_ops && vc->comm_ops->send)
    {
	mpi_errno = vc->comm_ops->send( vc, buf, count, datatype, rank, tag, comm, context_offset, &sreq);
	goto fn_exit;
    }
#endif

    MPIDI_Datatype_get_info(count, datatype, dt_contig, data_sz, dt_ptr, 
			    dt_true_lb);


    if (data_sz == 0)
    {
	MPIDI_CH3_Pkt_t upkt;
	MPIDI_CH3_Pkt_eager_send_t * const eager_pkt = &upkt.eager_send;

	MPIU_DBG_MSG(CH3_OTHER,VERBOSE,"sending zero length message");
	MPIDI_Pkt_init(eager_pkt, MPIDI_CH3_PKT_EAGER_SEND);
	eager_pkt->match.parts.rank = comm->rank;
	eager_pkt->match.parts.tag = tag;
	eager_pkt->match.parts.context_id = comm->context_id + context_offset;
	eager_pkt->sender_req_id = MPI_REQUEST_NULL;
	eager_pkt->data_sz = 0;
	
	MPIDI_VC_FAI_send_seqnum(vc, seqnum);
	MPIDI_Pkt_set_seqnum(eager_pkt, seqnum);
	
	MPIU_THREAD_CS_ENTER(CH3COMM,vc);
	mpi_errno = MPIDI_CH3_iStartMsg(vc, eager_pkt, sizeof(*eager_pkt), &sreq);
	MPIU_THREAD_CS_EXIT(CH3COMM,vc);
	/* --BEGIN ERROR HANDLING-- */
	if (mpi_errno != MPI_SUCCESS)
	{
	    MPIU_ERR_SETANDJUMP(mpi_errno,MPI_ERR_OTHER,"**ch3|eagermsg");
	}
	/* --END ERROR HANDLING-- */
	if (sreq != NULL)
	{
	    MPIDI_Request_set_seqnum(sreq, seqnum);
	    MPIDI_Request_set_type(sreq, MPIDI_REQUEST_TYPE_SEND);
	    /* sreq->comm = comm;
	      MPIR_Comm_add_ref(comm); -- not necessary for blocking functions */
	}
	
	goto fn_exit;
    }
    
    /* FIXME: flow control: limit number of outstanding eager messsages 
       containing data and need to be buffered by the receiver */
#ifdef USE_EAGER_SHORT
    if (dt_contig && data_sz <= MPIDI_EAGER_SHORT_SIZE) {
	mpi_errno = MPIDI_CH3_EagerContigShortSend( &sreq, 
					       MPIDI_CH3_PKT_EAGERSHORT_SEND,
					       (char *)buf + dt_true_lb,
					       data_sz, rank, tag, comm, 
					       context_offset );
    }
    else
#endif
    if (data_sz + sizeof(MPIDI_CH3_Pkt_eager_send_t) <=	
	vc->eager_max_msg_sz) {
	if (dt_contig) {
 	    mpi_errno = MPIDI_CH3_EagerContigSend( &sreq, 
						   MPIDI_CH3_PKT_EAGER_SEND,
						   (char *)buf + dt_true_lb,
						   data_sz, rank, tag, comm, 
						   context_offset );
	}
	else {
	    MPIDI_Request_create_sreq(sreq, mpi_errno, goto fn_exit);
	    MPIDI_Request_set_type(sreq, MPIDI_REQUEST_TYPE_SEND);
	    mpi_errno = MPIDI_CH3_EagerNoncontigSend( &sreq, 
                                                      MPIDI_CH3_PKT_EAGER_SEND,
                                                      buf, count, datatype,
                                                      data_sz, rank, tag, 
                                                      comm, context_offset );
	}
    }
    else {
Beispiel #5
0
int MPID_Ssend(const void * buf, int count, MPI_Datatype datatype, int rank, int tag, MPID_Comm * comm, int context_offset,
	       MPID_Request ** request)
{
    MPIDI_msg_sz_t data_sz;
    int dt_contig;
    MPI_Aint dt_true_lb;
    MPID_Datatype * dt_ptr;
    MPID_Request * sreq = NULL;
    MPIDI_VC_t * vc;
    int mpi_errno = MPI_SUCCESS;
    MPIDI_STATE_DECL(MPID_STATE_MPID_SSEND);

    MPIDI_FUNC_ENTER(MPID_STATE_MPID_SSEND);

    MPIU_DBG_MSG_FMT(CH3_OTHER,VERBOSE,(MPIU_DBG_FDEST,
              "rank=%d, tag=%d, context=%d", 
              rank, tag, comm->context_id + context_offset));

    if (rank == comm->rank && comm->comm_kind != MPID_INTERCOMM)
    {
#if defined(_OSU_PSM_)
    goto skip_self_send;     /* PSM internally, will optimize self-send */
#endif
	mpi_errno = MPIDI_Isend_self(buf, count, datatype, rank, tag, comm, 
				     context_offset, MPIDI_REQUEST_TYPE_SSEND, 
				     &sreq);
	/* In the single threaded case, sending to yourself will cause 
	   deadlock.  Note that in the runtime-thread case, this check
	   will not be made (long-term FIXME) */
#       ifndef MPICH_IS_THREADED
	{
	    /* --BEGIN ERROR HANDLING-- */
	    if (sreq != NULL && sreq->cc != 0)
	    {
		mpi_errno = MPIR_Err_create_code(MPI_SUCCESS, MPIR_ERR_RECOVERABLE, FCNAME, __LINE__, MPI_ERR_OTHER,
						 "**dev|selfsenddeadlock", 0);
		goto fn_exit;
	    }
	    /* --END ERROR HANDLING-- */
	}
#	endif
	goto fn_exit;
    }
#if defined (_OSU_PSM_)
skip_self_send:
#endif        
    if (rank == MPI_PROC_NULL)
    {
	goto fn_exit;
    }

    MPIDI_Comm_get_vc_set_active(comm, rank, &vc);

#ifdef ENABLE_COMM_OVERRIDES
    if (vc->comm_ops && vc->comm_ops->ssend)
    {
	mpi_errno = vc->comm_ops->ssend( vc, buf, count, datatype, rank, tag, comm, context_offset, &sreq);
	goto fn_exit;
    }
#endif

    
    MPIDI_Datatype_get_info(count, datatype, dt_contig, data_sz, dt_ptr, dt_true_lb);

    MPIDI_Request_create_sreq(sreq, mpi_errno, goto fn_exit);
    MPIDI_Request_set_type(sreq, MPIDI_REQUEST_TYPE_SSEND);

    if (data_sz == 0)
    {
#if defined (_OSU_PSM_)
    goto psm_ssend;
#endif
	mpi_errno = MPIDI_CH3_EagerSyncZero( &sreq, rank, tag, comm, 
					     context_offset );
	goto fn_exit;
    }
#if defined (_OSU_PSM_)
psm_ssend:
    sreq->psm_flags |= PSM_SYNC_SEND;
    if(dt_contig) {
        PSMSG(fprintf(stderr, "psm Sync send\n"));
        mpi_errno = MPIDI_CH3_EagerContigSend(&sreq, MPIDI_CH3_PKT_EAGER_SEND,
                       (char *)buf + dt_true_lb, data_sz, rank, tag, comm,
                        context_offset);
    } else {
        PSMSG(fprintf(stderr, "psm NC-Sync send\n"));
        mpi_errno = MPIDI_CH3_EagerNoncontigSend(&sreq,
                        MPIDI_CH3_PKT_EAGER_SEND, buf, count, datatype, data_sz,
                        rank, tag, comm, context_offset);
    }
    goto fn_exit;
#endif /* _OSU_PSM_ */
    
#if defined(_OSU_MVAPICH_)
    if (data_sz + sizeof(MPIDI_CH3_Pkt_eager_sync_send_t) <= vc->eager_max_msg_sz
        && ! vc->force_rndv)
#else /* defined(_OSU_MVAPICH_) */
    if (data_sz + sizeof(MPIDI_CH3_Pkt_eager_sync_send_t) <= vc->eager_max_msg_sz)
#endif /* defined(_OSU_MVAPICH_) */
    {
	mpi_errno = MPIDI_CH3_EagerSyncNoncontigSend( &sreq, buf, count,
                                                      datatype, data_sz, 
                                                      dt_contig, dt_true_lb,
                                                      rank, tag, comm, 
                                                      context_offset );
    }
    else
    {
	/* Note that the sreq was created above */
	mpi_errno = vc->rndvSend_fn( &sreq, buf, count, datatype, dt_contig,
                                     data_sz, dt_true_lb, rank, tag, comm, 
                                     context_offset );
	/* Note that we don't increase the ref cound on the datatype
	   because this is a blocking call, and the calling routine 
	   must wait until sreq completes */
    }

  fn_exit:
    *request = sreq;
    
    MPIU_DBG_STMT(CH3_OTHER,VERBOSE,{if (sreq!=NULL) {
            MPIU_DBG_MSG_P(CH3_OTHER,VERBOSE,
			   "request allocated, handle=0x%08x", sreq->handle);}});
Beispiel #6
0
int MPID_Isend(const void * buf, int count, MPI_Datatype datatype, int rank, 
	       int tag, MPID_Comm * comm, int context_offset,
               MPID_Request ** request)
{
    MPIDI_msg_sz_t data_sz;
    int dt_contig;
    MPI_Aint dt_true_lb;
    MPID_Datatype * dt_ptr;
    MPID_Request * sreq;
    MPIDI_VC_t * vc=0;
#if defined(MPID_USE_SEQUENCE_NUMBERS)
    MPID_Seqnum_t seqnum;
#endif    
    int eager_threshold = -1;
    int mpi_errno = MPI_SUCCESS;
    MPIDI_STATE_DECL(MPID_STATE_MPID_ISEND);

    MPIDI_FUNC_ENTER(MPID_STATE_MPID_ISEND);

    MPIU_DBG_MSG_FMT(CH3_OTHER,VERBOSE,(MPIU_DBG_FDEST,
                  "rank=%d, tag=%d, context=%d", 
                  rank, tag, comm->context_id + context_offset));
    
    if (rank == comm->rank && comm->comm_kind != MPID_INTERCOMM)
    {
	mpi_errno = MPIDI_Isend_self(buf, count, datatype, rank, tag, comm, 
			    context_offset, MPIDI_REQUEST_TYPE_SEND, &sreq);
	goto fn_exit;
    }

    if (rank != MPI_PROC_NULL) {
        MPIDI_Comm_get_vc_set_active(comm, rank, &vc);
#ifdef ENABLE_COMM_OVERRIDES
        /* this needs to come before the sreq is created, since the override
         * function is responsible for creating its own request */
        if (vc->comm_ops && vc->comm_ops->isend)
        {
            mpi_errno = vc->comm_ops->isend( vc, buf, count, datatype, rank, tag, comm, context_offset, &sreq);
            goto fn_exit;
        }
#endif
    }

    MPIDI_Request_create_sreq(sreq, mpi_errno, goto fn_exit);
    MPIDI_Request_set_type(sreq, MPIDI_REQUEST_TYPE_SEND);

    if (rank == MPI_PROC_NULL)
    {
	MPIU_Object_set_ref(sreq, 1);
        MPID_cc_set(&sreq->cc, 0);
	goto fn_exit;
    }

    MPIDI_Datatype_get_info(count, datatype, dt_contig, data_sz, dt_ptr, 
			    dt_true_lb);
    
    if (data_sz == 0)
    {
	MPIDI_CH3_Pkt_t upkt;
	MPIDI_CH3_Pkt_eager_send_t * const eager_pkt = &upkt.eager_send;

	MPIDI_Request_set_msg_type(sreq, MPIDI_REQUEST_EAGER_MSG);
	sreq->dev.OnDataAvail = 0;
	    
	MPIU_DBG_MSG(CH3_OTHER,VERBOSE,"sending zero length message");
	MPIDI_Pkt_init(eager_pkt, MPIDI_CH3_PKT_EAGER_SEND);
	eager_pkt->match.parts.rank = comm->rank;
	eager_pkt->match.parts.tag = tag;
	eager_pkt->match.parts.context_id = comm->context_id + context_offset;
	eager_pkt->sender_req_id = sreq->handle;
	eager_pkt->data_sz = 0;
	
	MPIDI_VC_FAI_send_seqnum(vc, seqnum);
	MPIDI_Pkt_set_seqnum(eager_pkt, seqnum);
	MPIDI_Request_set_seqnum(sreq, seqnum);
	
	MPIU_THREAD_CS_ENTER(CH3COMM,vc);
	mpi_errno = MPIDI_CH3_iSend(vc, sreq, eager_pkt, sizeof(*eager_pkt));
	MPIU_THREAD_CS_EXIT(CH3COMM,vc);
	/* --BEGIN ERROR HANDLING-- */
	if (mpi_errno != MPI_SUCCESS)
	{
	    MPIU_Object_set_ref(sreq, 0);
	    MPIDI_CH3_Request_destroy(sreq);
	    sreq = NULL;
            MPIU_ERR_SET(mpi_errno, MPI_ERR_OTHER, "**ch3|eagermsg");
	    goto fn_exit;
	}
	/* --END ERROR HANDLING-- */

	goto fn_exit;
    }

    MPIDI_CH3_GET_EAGER_THRESHOLD(&eager_threshold, comm, vc);

    /* FIXME: flow control: limit number of outstanding eager messages
       containing data and need to be buffered by the receiver */
    if (data_sz + sizeof(MPIDI_CH3_Pkt_eager_send_t) <= eager_threshold)
    {
	if (dt_contig)
	{
	    mpi_errno = MPIDI_CH3_EagerContigIsend( &sreq, 
						    MPIDI_CH3_PKT_EAGER_SEND,
						    (char*)buf + dt_true_lb, 
						    data_sz, rank, tag, 
						    comm, context_offset );
	}
	else
	{
	    mpi_errno = MPIDI_CH3_EagerNoncontigSend( &sreq, 
                                                      MPIDI_CH3_PKT_EAGER_SEND,
                                                      buf, count, datatype,
                                                      data_sz, rank, tag, 
                                                      comm, context_offset );
	    /* If we're not complete, then add a reference to the datatype */
	    if (sreq && sreq->dev.OnDataAvail) {
		sreq->dev.datatype_ptr = dt_ptr;
		MPID_Datatype_add_ref(dt_ptr);
	    }
	}
    }
    else
    {
	/* Note that the sreq was created above */
	MPIDI_Request_set_msg_type( sreq, MPIDI_REQUEST_RNDV_MSG );
	mpi_errno = vc->rndvSend_fn( &sreq, buf, count, datatype, dt_contig,
                                     data_sz, dt_true_lb, rank, tag, comm, 
                                     context_offset );
	/* FIXME: fill temporary IOV or pack temporary buffer after send to 
	   hide some latency.  This requires synchronization
           because the CTS packet could arrive and be processed before the 
	   above iStartmsg completes (depending on the progress
           engine, threads, etc.). */
	
	if (sreq && dt_ptr != NULL)
	{
	    sreq->dev.datatype_ptr = dt_ptr;
	    MPID_Datatype_add_ref(dt_ptr);
	}
    }

  fn_exit:
    *request = sreq;

    MPIU_DBG_STMT(CH3_OTHER,VERBOSE,
    {
	if (sreq != NULL)
	{
	    MPIU_DBG_MSG_P(CH3_OTHER,VERBOSE,"request allocated, handle=0x%08x", sreq->handle);
	}
    }
		  );
Beispiel #7
0
int MPID_Rsend(const void * buf, int count, MPI_Datatype datatype, int rank, int tag, MPID_Comm * comm, int context_offset,
	       MPID_Request ** request)
{
    MPIDI_msg_sz_t data_sz;
    int dt_contig;
    MPI_Aint dt_true_lb;
    MPID_Datatype * dt_ptr;
    MPID_Request * sreq = NULL;
    MPIDI_VC_t * vc;
#if defined(MPID_USE_SEQUENCE_NUMBERS)
    MPID_Seqnum_t seqnum;
#endif    
    int mpi_errno = MPI_SUCCESS;    
    MPIDI_STATE_DECL(MPID_STATE_MPID_RSEND);

    MPIDI_FUNC_ENTER(MPID_STATE_MPID_RSEND);

    MPIU_DBG_MSG_FMT(CH3_OTHER,VERBOSE,(MPIU_DBG_FDEST,
					"rank=%d, tag=%d, context=%d", 
                              rank, tag, comm->context_id + context_offset));

    /* Check to make sure the communicator hasn't already been revoked */
    if (comm->revoked &&
            MPIR_AGREE_TAG != MPIR_TAG_MASK_ERROR_BITS(tag & ~MPIR_Process.tagged_coll_mask) &&
            MPIR_SHRINK_TAG != MPIR_TAG_MASK_ERROR_BITS(tag & ~MPIR_Process.tagged_coll_mask)) {
        MPIR_ERR_SETANDJUMP(mpi_errno,MPIX_ERR_REVOKED,"**revoked");
    }
    
    if (rank == comm->rank && comm->comm_kind != MPID_INTERCOMM)
    {
	mpi_errno = MPIDI_Isend_self(buf, count, datatype, rank, tag, comm, context_offset, MPIDI_REQUEST_TYPE_RSEND, &sreq);
	goto fn_exit;
    }

    if (rank == MPI_PROC_NULL)
    {
	goto fn_exit;
    }

    MPIDI_Comm_get_vc_set_active(comm, rank, &vc);

#ifdef ENABLE_COMM_OVERRIDES
    if (vc->comm_ops && vc->comm_ops->rsend)
    {
	mpi_errno = vc->comm_ops->rsend( vc, buf, count, datatype, rank, tag, comm, context_offset, &sreq);
	goto fn_exit;
    }
#endif

    MPIDI_Datatype_get_info(count, datatype, dt_contig, data_sz, dt_ptr, dt_true_lb);

    if (data_sz == 0)
    {
	MPIDI_CH3_Pkt_t upkt;
	MPIDI_CH3_Pkt_ready_send_t * const ready_pkt = &upkt.ready_send;

	MPIU_DBG_MSG(CH3_OTHER,VERBOSE,"sending zero length message");
    
	MPIDI_Pkt_init(ready_pkt, MPIDI_CH3_PKT_READY_SEND);
	ready_pkt->match.parts.rank = comm->rank;
	ready_pkt->match.parts.tag = tag;
	ready_pkt->match.parts.context_id = comm->context_id + context_offset;
	ready_pkt->sender_req_id = MPI_REQUEST_NULL;
	ready_pkt->data_sz = data_sz;

	MPIDI_VC_FAI_send_seqnum(vc, seqnum);
	MPIDI_Pkt_set_seqnum(ready_pkt, seqnum);
	
	MPID_THREAD_CS_ENTER(POBJ, vc->pobj_mutex);
	mpi_errno = MPIDI_CH3_iStartMsg(vc, ready_pkt, sizeof(*ready_pkt), &sreq);
	MPID_THREAD_CS_EXIT(POBJ, vc->pobj_mutex);
	/* --BEGIN ERROR HANDLING-- */
	if (mpi_errno != MPI_SUCCESS)
	{
	    mpi_errno = MPIR_Err_create_code(mpi_errno, MPIR_ERR_RECOVERABLE, FCNAME, __LINE__, MPI_ERR_OTHER, "**ch3|eagermsg", 0);
	    goto fn_exit;
	}
	/* --END ERROR HANDLING-- */
	if (sreq != NULL)
	{
	    MPIDI_Request_set_seqnum(sreq, seqnum);
	    MPIDI_Request_set_type(sreq, MPIDI_REQUEST_TYPE_RSEND);
	    /* sreq->comm = comm;
	       MPIR_Comm_add_ref(comm); -- not needed for blocking operations */
	}

	goto fn_exit;
    }
    
    if (vc->ready_eager_max_msg_sz < 0 || data_sz + sizeof(MPIDI_CH3_Pkt_ready_send_t) <= vc->ready_eager_max_msg_sz) {
        if (dt_contig)
        {
            mpi_errno = MPIDI_CH3_EagerContigSend( &sreq,
                                                   MPIDI_CH3_PKT_READY_SEND,
                                                   (char *)buf + dt_true_lb,
                                                   data_sz, rank, tag, comm,
                                                   context_offset );
        }
        else
        {
            MPIDI_Request_create_sreq(sreq, mpi_errno, goto fn_exit);
            MPIDI_Request_set_type(sreq, MPIDI_REQUEST_TYPE_SEND);
            mpi_errno = MPIDI_CH3_EagerNoncontigSend( &sreq,
                                                      MPIDI_CH3_PKT_READY_SEND,
                                                      buf, count, datatype,
                                                      data_sz, rank, tag,
                                                      comm, context_offset );
        }
    } else {
int MPID_Irsend(const void * buf, int count, MPI_Datatype datatype, int rank, int tag, MPID_Comm * comm, int context_offset,
		MPID_Request ** request)
{
    MPIDI_CH3_Pkt_t upkt;
    MPIDI_CH3_Pkt_ready_send_t * const ready_pkt = &upkt.ready_send;
    MPIDI_msg_sz_t data_sz;
    int dt_contig;
    MPI_Aint dt_true_lb;
    MPID_Datatype * dt_ptr;
    MPID_Request * sreq;
    MPIDI_VC_t * vc;
#if defined(MPID_USE_SEQUENCE_NUMBERS)
    MPID_Seqnum_t seqnum;
#endif    
    int mpi_errno = MPI_SUCCESS;    
    MPIDI_STATE_DECL(MPID_STATE_MPID_IRSEND);

    MPIDI_FUNC_ENTER(MPID_STATE_MPID_IRSEND);

    MPIU_DBG_MSG_FMT(CH3_OTHER,VERBOSE,(MPIU_DBG_FDEST,
                "rank=%d, tag=%d, context=%d", 
                rank, tag, comm->context_id + context_offset));
    
    if (rank == comm->rank && comm->comm_kind != MPID_INTERCOMM)
    {
	mpi_errno = MPIDI_Isend_self(buf, count, datatype, rank, tag, comm, context_offset, MPIDI_REQUEST_TYPE_RSEND, &sreq);
	goto fn_exit;
    }
    
    MPIDI_Request_create_sreq(sreq, mpi_errno, goto fn_exit);
    MPIDI_Request_set_type(sreq, MPIDI_REQUEST_TYPE_RSEND);
    MPIDI_Request_set_msg_type(sreq, MPIDI_REQUEST_EAGER_MSG);
    
    if (rank == MPI_PROC_NULL)
    {
	MPIU_Object_set_ref(sreq, 1);
        MPID_cc_set(&sreq->cc, 0);
	goto fn_exit;
    }
    
    MPIDI_Comm_get_vc_set_active(comm, rank, &vc);

#ifdef ENABLE_COMM_OVERRIDES
    if (vc->comm_ops && vc->comm_ops->irsend)
    {
	mpi_errno = vc->comm_ops->irsend( vc, buf, count, datatype, rank, tag, comm, context_offset, &sreq);
	goto fn_exit;
    }
#endif
    
    MPIDI_Datatype_get_info(count, datatype, dt_contig, data_sz, dt_ptr, dt_true_lb);

    MPIDI_Pkt_init(ready_pkt, MPIDI_CH3_PKT_READY_SEND);
    ready_pkt->match.parts.rank = comm->rank;
    ready_pkt->match.parts.tag = tag;
    ready_pkt->match.parts.context_id = comm->context_id + context_offset;
    ready_pkt->sender_req_id = MPI_REQUEST_NULL;
    ready_pkt->data_sz = data_sz;

    if (data_sz == 0)
    {
	MPIU_DBG_MSG(CH3_OTHER,VERBOSE,"sending zero length message");

	sreq->dev.OnDataAvail = 0;
	
	MPIDI_VC_FAI_send_seqnum(vc, seqnum);
	MPIDI_Pkt_set_seqnum(ready_pkt, seqnum);
	MPIDI_Request_set_seqnum(sreq, seqnum);
	
	MPIU_THREAD_CS_ENTER(CH3COMM,vc);
	mpi_errno = MPIU_CALL(MPIDI_CH3,iSend(vc, sreq, ready_pkt, sizeof(*ready_pkt)));
	MPIU_THREAD_CS_EXIT(CH3COMM,vc);
	/* --BEGIN ERROR HANDLING-- */
	if (mpi_errno != MPI_SUCCESS)
	{
	    MPIU_Object_set_ref(sreq, 0);
	    MPIDI_CH3_Request_destroy(sreq);
	    sreq = NULL;
            MPIU_ERR_SET(mpi_errno, MPI_ERR_OTHER, "**ch3|eagermsg");
	    goto fn_exit;
	}
	/* --END ERROR HANDLING-- */
	goto fn_exit;
    }
    
    if (dt_contig) {
	mpi_errno = MPIDI_CH3_EagerContigIsend( &sreq, 
						MPIDI_CH3_PKT_READY_SEND,
						(char*)buf + dt_true_lb, 
						data_sz, rank, tag, 
						comm, context_offset );

    }
    else {
	mpi_errno = MPIDI_CH3_EagerNoncontigSend( &sreq, 
                                                  MPIDI_CH3_PKT_READY_SEND,
                                                  buf, count, datatype,
                                                  data_sz, rank, tag, 
                                                  comm, context_offset );
	/* If we're not complete, then add a reference to the datatype */
	if (sreq && sreq->dev.OnDataAvail) {
	    sreq->dev.datatype_ptr = dt_ptr;
	    MPID_Datatype_add_ref(dt_ptr);
	}
    }
 
  fn_exit:
    *request = sreq;

    MPIU_DBG_STMT(CH3_OTHER,VERBOSE,{
	if (sreq != NULL)
	{
	    MPIU_DBG_MSG_P(CH3_OTHER,VERBOSE,"request allocated, handle=0x%08x", sreq->handle);
	}
    }
		  );