ch3_istartmsg.c

mpi并行计算的c++代码 可用vc或gcc编译通过 可以用来搭建并行计算试验环境

/* -*- Mode: C; c-basic-offset:4 ; -*- */
/*
 *  (C) 2001 by Argonne National Laboratory.
 *      See COPYRIGHT in top-level directory.
 */

#include "mpidi_ch3_impl.h"


/*
 * MPIDI_CH3_iStartMsg() attempts to send the message immediately.  If
 * the entire message is successfully sent, then NULL is returned.
 * Otherwise a request is allocated, the header is copied into the
 * request, and a pointer to the request is returned.  An error
 * condition also results in a request be allocated and the errror
 * being returned in the status field of the request.
 */
#undef FUNCNAME
#define FUNCNAME MPIDI_CH3_iStartMsg
#undef FCNAME
#define FCNAME MPIDI_QUOTE(FUNCNAME)
int MPIDI_CH3_iStartMsg(MPIDI_VC_t * vc, void * hdr, MPIDI_msg_sz_t hdr_sz,
			MPID_Request ** sreq_ptr)
{
    int mpi_errno = MPI_SUCCESS;
    int gn_errno;
    MPID_Request * sreq = NULL;
    MPIDI_STATE_DECL(MPID_STATE_MPIDI_CH3_ISTARTMSG);

    MPIDI_FUNC_ENTER(MPID_STATE_MPIDI_CH3_ISTARTMSG);

    MPIDI_DBG_PRINTF((50, FCNAME, "entering"));
    MPIU_Assert(hdr_sz <= sizeof(MPIDI_CH3_Pkt_t));

    /* This channel uses a fixed length header, the size of which is
     * the maximum of all possible packet headers */
    hdr_sz = sizeof(MPIDI_CH3_Pkt_t);
    MPIDI_DBG_Print_packet((MPIDI_CH3_Pkt_t*)hdr);

    if (MPIDI_CH3I_SendQ_empty (CH3_NORMAL_QUEUE) && !MPIDI_CH3I_inside_handler)
       /* MT */
    {
	gn_errno = gasnet_AMRequestMedium0 (vc->lpid,
					    MPIDI_CH3_start_packet_handler_id,
					    hdr, hdr_sz);
	if (gn_errno != GASNET_OK)
	{
	    MPID_Abort(NULL, MPI_SUCCESS, -1, "GASNet send failed");
	}
    }
    else
    {
	int i;
	
	MPIDI_DBG_PRINTF((55, FCNAME, "enqueuing"));

	/* create a request */
	sreq = MPIDI_CH3_Request_create();
	MPIU_Assert(sreq != NULL);
	MPIU_Object_set_ref(sreq, 2);
	sreq->kind = MPID_REQUEST_SEND;

	sreq->gasnet.pkt = *(MPIDI_CH3_Pkt_t *) hdr;
	sreq->dev.iov[0].MPID_IOV_BUF = (char *) &sreq->gasnet.pkt;
	sreq->dev.iov[0].MPID_IOV_LEN = hdr_sz;
	sreq->dev.iov_count = 1;
	sreq->gasnet.iov_offset = 0;
	sreq->gasnet.vc = vc;
	sreq->dev.ca = MPIDI_CH3_CA_COMPLETE;
	MPIDI_CH3I_SendQ_enqueue (sreq, CH3_NORMAL_QUEUE);
    }

    *sreq_ptr = sreq;

    MPIDI_DBG_PRINTF((50, FCNAME, "exiting"));
    MPIDI_FUNC_EXIT(MPID_STATE_MPIDI_CH3_ISTARTMSG);
    return mpi_errno;
}