/* -*- Mode: C; c-basic-offset:4 ; -*- */
/*
 *  (C) 2006 by Argonne National Laboratory.
 *      See COPYRIGHT in top-level directory.
 *
 *  Portions of this code were written by Intel Corporation.
 *  Copyright (C) 2011-2016 Intel Corporation.  Intel provides this material
 *  to Argonne National Laboratory subject to Software Grant and Corporate
 *  Contributor License Agreement dated February 8, 2012.
 */
#ifndef CH4R_REQUEST_H_INCLUDED
#define CH4R_REQUEST_H_INCLUDED

#include "ch4_types.h"
#include "ch4r_buf.h"

#undef FUNCNAME
#define FUNCNAME MPIDI_CH4I_am_request_create
#undef FCNAME
#define FCNAME MPL_QUOTE(FUNCNAME)
static inline MPIR_Request *MPIDI_CH4I_am_request_create(MPIR_Request_kind_t kind, int ref_count)
{
    MPIR_Request *req;
    int i;

    MPIR_FUNC_VERBOSE_STATE_DECL(MPID_STATE_MPIDI_CH4I_AM_REQUEST_CREATE);
    MPIR_FUNC_VERBOSE_ENTER(MPID_STATE_MPIDI_CH4I_AM_REQUEST_CREATE);

    req = MPIR_Request_create(kind);

    /* as long as ref_count is a constant, any compiler should be able
     * to unroll the below loop.  when threading is not enabled, the
     * compiler should be able to combine the below individual
     * increments to a single increment of "ref_count - 1".
     *
     * FIXME: when threading is enabled, the ref_count increase is an
     * atomic operation, so it might be more inefficient.  we should
     * use a new API to increase the ref_count value instead of the
     * for loop. */
    for (i = 0; i < ref_count - 1; i++)
        MPIR_Request_add_ref(req);

    MPIDI_NM_am_request_init(req);

    CH4_COMPILE_TIME_ASSERT(sizeof(MPIDI_CH4U_req_ext_t) <= MPIDI_CH4I_BUF_POOL_SZ);
    MPIDI_CH4U_REQUEST(req, req) =
        (MPIDI_CH4U_req_ext_t *) MPIDI_CH4R_get_buf(MPIDI_CH4_Global.buf_pool);
    MPIR_Assert(MPIDI_CH4U_REQUEST(req, req));
    MPIDI_CH4U_REQUEST(req, req->status) = 0;

    MPIR_FUNC_VERBOSE_EXIT(MPID_STATE_MPIDI_CH4I_AM_REQUEST_CREATE);
    return req;
}

/* This function should be called any time an anysource request is matched so
 * the upper layer will have a chance to arbitrate who wins the race between
 * the netmod and the shmod. This will cancel the request of the other side and
 * take care of copying any relevant data. */
static inline int MPIDI_CH4R_anysource_matched(MPIR_Request * rreq, int caller,
                                               int *continue_matching)
{
    int mpi_errno = MPI_SUCCESS;

    MPIR_FUNC_VERBOSE_STATE_DECL(MPID_STATE_MPIDI_CH4R_ANYSOURCE_MATCHED);
    MPIR_FUNC_VERBOSE_ENTER(MPID_STATE_MPIDI_CH4R_ANYSOURCE_MATCHED);

    MPIR_Assert(MPIDI_CH4R_NETMOD == caller || MPIDI_CH4R_SHM == caller);

    if (MPIDI_CH4R_NETMOD == caller) {
#ifdef MPIDI_BUILD_CH4_SHM
        mpi_errno = MPIDI_SHM_mpi_cancel_recv(rreq);

        /* If the netmod is cancelling the request, then shared memory will
         * just copy the status from the shared memory side because the netmod
         * will always win the race condition here. */
        if (MPIR_STATUS_GET_CANCEL_BIT(rreq->status)) {
            /* If the request is cancelled, copy the status object from the
             * partner request */
            rreq->status = MPIDI_CH4I_REQUEST_ANYSOURCE_PARTNER(rreq)->status;
        }
#endif
        *continue_matching = 0;
    }
    else if (MPIDI_CH4R_SHM == caller) {
        mpi_errno = MPIDI_NM_mpi_cancel_recv(rreq);

        /* If the netmod has already matched this request, shared memory will
         * lose and should stop matching this request */
        *continue_matching = !MPIR_STATUS_GET_CANCEL_BIT(rreq->status);
    }

    MPIR_FUNC_VERBOSE_EXIT(MPID_STATE_MPIDI_CH4R_ANYSOURCE_MATCHED);
    return mpi_errno;
}

#endif /* CH4R_REQUEST_H_INCLUDED */
