# vim: set ft=c:

MPI_Bsend:
    .desc: Basic send with user-provided buffering
    .seealso: MPI_Buffer_attach, MPI_Ibsend, MPI_Bsend_init
    .earlyreturn: pt2pt_proc_null
/*
    Notes:
    This send is provided as a convenience function; it allows the user to
    send messages without worring about where they are buffered (because the
    user `must` have provided buffer space with 'MPI_Buffer_attach').

    In deciding how much buffer space to allocate, remember that the buffer space
    is not available for reuse by subsequent 'MPI_Bsend's unless you are certain
    that the message
    has been received (not just that it should have been received).  For example,
    this code does not allocate enough buffer space
    .vb
        MPI_Buffer_attach(b, n*sizeof(double) + MPI_BSEND_OVERHEAD);
        for (i=0; i<m; i++) {
            MPI_Bsend(buf, n, MPI_DOUBLE, ...);
        }
    .ve
    because only enough buffer space is provided for a single send, and the
    loop may start a second 'MPI_Bsend' before the first is done making use of the
    buffer.

    In C, you can
    force the messages to be delivered by
    .vb
        MPI_Buffer_detach(&b, &n);
        MPI_Buffer_attach(b, n);
    .ve
    (The 'MPI_Buffer_detach' will not complete until all buffered messages are
    delivered.)
*/
{
    mpi_errno = MPIR_Bsend_isend(buf, count, datatype, dest, tag, comm_ptr, NULL);
    if (mpi_errno != MPI_SUCCESS)
        goto fn_fail;
}

MPI_Bsend_init:
    .desc: Builds a handle for a buffered send
    .seealso: MPI_Buffer_attach
{
    MPIR_Request *request_ptr = NULL;

    mpi_errno = MPID_Bsend_init(buf, count, datatype, dest, tag, comm_ptr,
                                MPIR_CONTEXT_INTRA_PT2PT, &request_ptr);
    if (mpi_errno != MPI_SUCCESS)
        goto fn_fail;

    /* return the handle of the request to the user */
    MPIR_OBJ_PUBLISH_HANDLE(*request, request_ptr->handle);
}

MPI_Buffer_attach:
    .desc: Attaches a user-provided buffer for sending
    .skip: ThreadSafe
    .seealso: MPI_Buffer_detach, MPI_Bsend
/*
    Notes:
    The size given should be the sum of the sizes of all outstanding Bsends that
    you intend to have, plus 'MPI_BSEND_OVERHEAD' for each Bsend that you do.
    For the purposes of calculating size, you should use 'MPI_Pack_size'.
    In other words, in the code
    .vb
         MPI_Buffer_attach(buffer, size);
         MPI_Bsend(..., count=20, datatype=type1,  ...);
         ...
         MPI_Bsend(..., count=40, datatype=type2, ...);
    .ve
    the value of 'size' in the 'MPI_Buffer_attach' call should be greater than
    the value computed by
    .vb
         MPI_Pack_size(20, type1, comm, &s1);
         MPI_Pack_size(40, type2, comm, &s2);
         size = s1 + s2 + 2 * MPI_BSEND_OVERHEAD;
    .ve
    The 'MPI_BSEND_OVERHEAD' gives the maximum amount of space that may be used in
    the buffer for use by the BSEND routines in using the buffer.  This value
    is in 'mpi.h' (for C) and 'mpif.h' (for Fortran).

    .N NotThreadSafe
    Because the buffer for buffered sends (e.g., 'MPI_Bsend') is shared by all
    threads in a process, the user is responsible for ensuring that only
    one thread at a time calls this routine or 'MPI_Buffer_detach'.
*/
{
    mpi_errno = MPIR_Bsend_attach(buffer, size);
    if (mpi_errno != MPI_SUCCESS)
        goto fn_fail;
}

MPI_Buffer_detach:
    .desc: Removes an existing buffer (for use in MPI_Bsend etc)
    .skip: ThreadSafe, Fortran
    .seealso: MPI_Buffer_attach
/*
    Notes:
        The reason that 'MPI_Buffer_detach' returns the address and size of the
    buffer being detached is to allow nested libraries to replace and restore
    the buffer.  For example, consider

    .vb
        int size, mysize, idummy;
        void *ptr, *myptr, *dummy;
        MPI_Buffer_detach(&ptr, &size);
        MPI_Buffer_attach(myptr, mysize);
        ...
        ... library code ...
        ...
        MPI_Buffer_detach(&dummy, &idummy);
        MPI_Buffer_attach(ptr, size);
    .ve

    This is much like the action of the Unix signal routine and has the same
    strengths (it is simple) and weaknesses (it only works for nested usages).

    Note that for this approach to work, MPI_Buffer_detach must return MPI_SUCCESS
    even when there is no buffer to detach.  In that case, it returns a size of
    zero.  The MPI 1.1 standard for 'MPI_BUFFER_DETACH' contains the text

    .vb
       The statements made in this section describe the behavior of MPI for
       buffered-mode sends. When no buffer is currently associated, MPI behaves
       as if a zero-sized buffer is associated with the process.
    .ve

    This could be read as applying only to the various Bsend routines.  This
    implementation takes the position that this applies to 'MPI_BUFFER_DETACH'
    as well.

    .N NotThreadSafe
    Because the buffer for buffered sends (e.g., 'MPI_Bsend') is shared by all
    threads in a process, the user is responsible for ensuring that only
    one thread at a time calls this routine or 'MPI_Buffer_attach'.

    .N Fortran

        The Fortran binding for this routine is different.  Because Fortran
        does not have pointers, it is impossible to provide a way to use the
        output of this routine to exchange buffers.  In this case, only the
        size field is set.

    Notes for C:
        Even though the 'bufferptr' argument is declared as 'void *', it is
        really the address of a void pointer.  See the rationale in the
        standard for more details.
*/

MPI_Ibsend:
    .desc: Starts a nonblocking buffered send
    .earlyreturn: pt2pt_proc_null
{
    mpi_errno = MPIR_Bsend_isend(buf, count, datatype, dest, tag, comm_ptr, NULL);
    if (mpi_errno)
        goto fn_fail;

    /* Ibsend is local-complete */
    MPIR_Request *request_ptr = MPIR_Request_create_complete(MPIR_REQUEST_KIND__SEND);
    *request = request_ptr->handle;
}

MPI_Improbe:
    .desc: Nonblocking matched probe.
    .earlyreturn: pt2pt_proc_null
{
    MPIR_Request *msgp = NULL;

    *message = MPI_MESSAGE_NULL;
    mpi_errno = MPID_Improbe(source, tag, comm_ptr, MPIR_CONTEXT_INTRA_PT2PT, flag, &msgp, status);
    MPIR_ERR_CHECK(mpi_errno);

    if (*flag) {
        MPIR_Assert(msgp != NULL);
        *message = msgp->handle;
    }
}

MPI_Imrecv:
    .desc: Nonblocking receive of message matched by MPI_Mprobe or MPI_Improbe.
{ -- early_return --
    if (message_ptr == NULL || message_ptr->handle == MPIR_REQUEST_NULL_RECV) {
        MPIR_Request *rreq;
        rreq = MPIR_Request_create_null_recv();
        *request = rreq->handle;
        *message = MPI_MESSAGE_NULL;
        goto fn_exit;
    }
}
{
    MPIR_Request *rreq = NULL;

    mpi_errno = MPID_Imrecv(buf, count, datatype, message_ptr, &rreq);
    MPIR_ERR_CHECK(mpi_errno);

    MPIR_Assert(rreq != NULL);
    *request = rreq->handle;
    *message = MPI_MESSAGE_NULL;
}

MPI_Iprobe:
    .desc: Nonblocking test for a message
    .earlyreturn: pt2pt_proc_null
{
    /* FIXME: Is this correct for intercomms? */
    mpi_errno = MPID_Iprobe(source, tag, comm_ptr, MPIR_CONTEXT_INTRA_PT2PT, flag, status);
    if (mpi_errno != MPI_SUCCESS)
        goto fn_fail;
}

MPI_Irecv:
    .desc: Begins a nonblocking receive
    .earlyreturn: pt2pt_proc_null
{
    MPIR_Request *request_ptr = NULL;

    mpi_errno = MPID_Irecv(buf, count, datatype, source, tag, comm_ptr,
                           MPIR_CONTEXT_INTRA_PT2PT, &request_ptr);
    /* return the handle of the request to the user */
    /* MPIU_OBJ_HANDLE_PUBLISH is unnecessary for irecv, lower-level access is
     * responsible for its own consistency, while upper-level field access is
     * controlled by the completion counter */
    *request = request_ptr->handle;

    /* Put this part after setting the request so that if the request is
     * pending (which is still considered an error), it will still be set
     * correctly here. For real error cases, the user might get garbage as
     * their request value, but that's fine since the definition is
     * undefined anyway. */
    if (mpi_errno != MPI_SUCCESS)
        goto fn_fail;
}

MPI_Irsend:
    .desc: Starts a nonblocking ready send
    .earlyreturn: pt2pt_proc_null
{
    MPIR_Request *request_ptr = NULL;

    mpi_errno = MPID_Irsend(buf, count, datatype, dest, tag, comm_ptr,
                            MPIR_CONTEXT_INTRA_PT2PT, &request_ptr);
    if (mpi_errno != MPI_SUCCESS)
        goto fn_fail;

    /* return the handle of the request to the user */
    /* MPIU_OBJ_HANDLE_PUBLISH is unnecessary for irsend, lower-level access is
     * responsible for its own consistency, while upper-level field access is
     * controlled by the completion counter */
    *request = request_ptr->handle;
}

MPI_Isend:
    .desc: Begins a nonblocking send
    .earlyreturn: pt2pt_proc_null
{
    MPIR_Request *request_ptr = NULL;

    mpi_errno = MPID_Isend(buf, count, datatype, dest, tag, comm_ptr,
                           MPIR_CONTEXT_INTRA_PT2PT, &request_ptr);
    if (mpi_errno != MPI_SUCCESS)
        goto fn_fail;

    /* return the handle of the request to the user */
    /* MPIU_OBJ_HANDLE_PUBLISH is unnecessary for isend, lower-level access is
     * responsible for its own consistency, while upper-level field access is
     * controlled by the completion counter */
    *request = request_ptr->handle;
}

MPI_Issend:
    .desc: Starts a nonblocking synchronous send
    .earlyreturn: pt2pt_proc_null
{
    MPIR_Request *request_ptr = NULL;

    mpi_errno = MPID_Issend(buf, count, datatype, dest, tag, comm_ptr,
                            MPIR_CONTEXT_INTRA_PT2PT, &request_ptr);
    if (mpi_errno != MPI_SUCCESS)
        goto fn_fail;

    /* return the handle of the request to the user */
    /* MPIU_OBJ_HANDLE_PUBLISH is unnecessary for issend, lower-level access is
     * responsible for its own consistency, while upper-level field access is
     * controlled by the completion counter */
    *request = request_ptr->handle;
}

MPI_Mprobe:
    .desc: Blocking matched probe.
    .earlyreturn: pt2pt_proc_null
{
    MPIR_Request *msgp = NULL;

    *message = MPI_MESSAGE_NULL;
    mpi_errno = MPID_Mprobe(source, tag, comm_ptr, MPIR_CONTEXT_INTRA_PT2PT, &msgp, status);
    MPIR_ERR_CHECK(mpi_errno);

    MPIR_Assert(msgp != NULL);
    *message = msgp->handle;
}

MPI_Mrecv:
    .desc: Blocking receive of message matched by MPI_Mprobe or MPI_Improbe.
{ -- early_return --
    if (message_ptr == NULL || message_ptr->handle == MPIR_REQUEST_NULL_RECV) {
        /* treat as though MPI_MESSAGE_NO_PROC was passed */
        MPIR_Status_set_procnull(status);
        *message = MPI_MESSAGE_NULL;
        goto fn_exit;
    }
}
{
    MPIR_Request *rreq = NULL;
    mpi_errno = MPID_Mrecv(buf, count, datatype, message_ptr, status, &rreq);
    MPIR_ERR_CHECK(mpi_errno);
    /* rreq == NULL implies message = MPI_MESSAGE_NO_PROC.
     * I.e, status was set and no need to wait on rreq */
    if (rreq != NULL) {
        mpi_errno = MPID_Wait(rreq, status);
        MPIR_ERR_CHECK(mpi_errno);

        mpi_errno = MPIR_Request_completion_processing(rreq, status);
        MPIR_Request_free(rreq);
        MPIR_ERR_CHECK(mpi_errno);
    }

    *message = MPI_MESSAGE_NULL;
}

MPI_Probe:
    .desc: Blocking test for a message
    .earlyreturn: pt2pt_proc_null
{
    mpi_errno = MPID_Probe(source, tag, comm_ptr, MPIR_CONTEXT_INTRA_PT2PT, status);
    if (mpi_errno != MPI_SUCCESS)
        goto fn_fail;
}

MPI_Recv:
    .desc: Blocking receive for a message
    .earlyreturn: pt2pt_proc_null
/*
    Notes:
    The 'count' argument indicates the maximum length of a message; the actual
    length of the message can be determined with 'MPI_Get_count'.
*/
{
    MPIR_Request *request_ptr = NULL;

    /* MT: Note that MPID_Recv may release the SINGLE_CS if it
     * decides to block internally.  MPID_Recv in that case will
     * re-aquire the SINGLE_CS before returning */
    mpi_errno = MPID_Recv(buf, count, datatype, source, tag, comm_ptr,
                          MPIR_CONTEXT_INTRA_PT2PT, status, &request_ptr);
    if (mpi_errno != MPI_SUCCESS)
        goto fn_fail;

    if (request_ptr == NULL) {
        goto fn_exit;
    }

    mpi_errno = MPID_Wait(request_ptr, MPI_STATUS_IGNORE);
    if (mpi_errno != MPI_SUCCESS)
        goto fn_fail;

    mpi_errno = request_ptr->status.MPI_ERROR;
    MPIR_Request_extract_status(request_ptr, status);
    MPIR_Request_free(request_ptr);

    if (mpi_errno != MPI_SUCCESS)
        goto fn_fail;
}

MPI_Recv_init:
    .desc: Create a persistent request for a receive
    .seealso: MPI_Start, MPI_Startall, MPI_Request_free
{
    MPIR_Request *request_ptr = NULL;

    mpi_errno = MPID_Recv_init(buf, count, datatype, source, tag, comm_ptr,
                               MPIR_CONTEXT_INTRA_PT2PT, &request_ptr);
    if (mpi_errno != MPI_SUCCESS)
        goto fn_fail;

    /* return the handle of the request to the user */
    MPIR_OBJ_PUBLISH_HANDLE(*request, request_ptr->handle);
}

MPI_Rsend:
    .desc: Blocking ready send
    .earlyreturn: pt2pt_proc_null
{
    MPIR_Request *request_ptr = NULL;

    mpi_errno = MPID_Rsend(buf, count, datatype, dest, tag, comm_ptr,
                           MPIR_CONTEXT_INTRA_PT2PT, &request_ptr);
    if (mpi_errno != MPI_SUCCESS)
        goto fn_fail;

    if (request_ptr == NULL) {
        goto fn_exit;
    }

    /* If a request was returned, then we need to block until the request
     * is complete */
    mpi_errno = MPID_Wait(request_ptr, MPI_STATUS_IGNORE);
    MPIR_ERR_CHECK(mpi_errno);

    mpi_errno = request_ptr->status.MPI_ERROR;
    MPIR_Request_free(request_ptr);

    if (mpi_errno != MPI_SUCCESS)
        goto fn_fail;
}

MPI_Rsend_init:
    .desc: Creates a persistent request for a ready send
    .seealso: MPI_Start, MPI_Request_free, MPI_Send_init
{
    MPIR_Request *request_ptr = NULL;

    mpi_errno = MPID_Rsend_init(buf, count, datatype, dest, tag, comm_ptr,
                                MPIR_CONTEXT_INTRA_PT2PT, &request_ptr);
    if (mpi_errno != MPI_SUCCESS)
        goto fn_fail;

    /* return the handle of the request to the user */
    MPIR_OBJ_PUBLISH_HANDLE(*request, request_ptr->handle);
}

MPI_Send:
    .desc: Performs a blocking send
    .seealso: MPI_Isend, MPI_Bsend
    .earlyreturn: pt2pt_proc_null
/*
    Notes:
    This routine may block until the message is received by the destination
    process.
*/
{
    MPIR_Request *request_ptr = NULL;

    mpi_errno = MPID_Send(buf, count, datatype, dest, tag, comm_ptr,
                          MPIR_CONTEXT_INTRA_PT2PT, &request_ptr);
    if (mpi_errno != MPI_SUCCESS)
        goto fn_fail;

    if (request_ptr == NULL) {
        goto fn_exit;
    }

    mpi_errno = MPID_Wait(request_ptr, MPI_STATUS_IGNORE);
    MPIR_ERR_CHECK(mpi_errno);

    mpi_errno = request_ptr->status.MPI_ERROR;
    MPIR_Request_free(request_ptr);

    if (mpi_errno != MPI_SUCCESS)
        goto fn_fail;
}

MPI_Send_init:
    .desc: Create a persistent request for a standard send
    .seealso: MPI_Start, MPI_Startall, MPI_Request_free
{
    MPIR_Request *request_ptr = NULL;

    mpi_errno = MPID_Send_init(buf, count, datatype, dest, tag, comm_ptr,
                               MPIR_CONTEXT_INTRA_PT2PT, &request_ptr);
    if (mpi_errno != MPI_SUCCESS)
        goto fn_fail;

    /* return the handle of the request to the user */
    MPIR_OBJ_PUBLISH_HANDLE(*request, request_ptr->handle);
}

MPI_Sendrecv:
    .desc: Sends and receives a message

MPI_Sendrecv_replace:
    .desc: Sends and receives using a single buffer
    .decl: MPIR_Sendrecv_replace_impl
{
#if defined(MPID_Sendrecv_replace)
    mpi_errno = MPID_Sendrecv_replace(buf, count, datatype, dest,
                                      sendtag, source, recvtag, comm_ptr, status);
#else
    mpi_errno = MPIR_Sendrecv_replace_impl(buf, count, datatype, dest,
                                           sendtag, source, recvtag, comm_ptr, status);
#endif

    if (mpi_errno != MPI_SUCCESS)
        goto fn_fail;
}

MPI_Ssend:
    .desc: Blocking synchronous send
    .earlyreturn: pt2pt_proc_null
{
    MPIR_Request *request_ptr = NULL;

    mpi_errno = MPID_Ssend(buf, count, datatype, dest, tag, comm_ptr,
                           MPIR_CONTEXT_INTRA_PT2PT, &request_ptr);
    if (mpi_errno != MPI_SUCCESS)
        goto fn_fail;

    if (request_ptr == NULL) {
        goto fn_exit;
    }

    /* If a request was returned, then we need to block until the request
     * is complete */
    mpi_errno = MPID_Wait(request_ptr, MPI_STATUS_IGNORE);
    MPIR_ERR_CHECK(mpi_errno);

    mpi_errno = request_ptr->status.MPI_ERROR;
    MPIR_Request_free(request_ptr);

    if (mpi_errno != MPI_SUCCESS)
        goto fn_fail;
}

MPI_Ssend_init:
    .desc: Creates a persistent request for a synchronous send
{
    MPIR_Request *request_ptr = NULL;

    mpi_errno = MPID_Ssend_init(buf, count, datatype, dest, tag, comm_ptr,
                                MPIR_CONTEXT_INTRA_PT2PT, &request_ptr);
    if (mpi_errno != MPI_SUCCESS)
        goto fn_fail;

    /* return the handle of the request to the user */
    MPIR_OBJ_PUBLISH_HANDLE(*request, request_ptr->handle);
}

MPI_Isendrecv:
    .desc: Starts a nonblocking send and receive

MPI_Isendrecv_replace:
    .desc: Starts a nonblocking send and receive with a single buffer
