/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */

/*

 *

 *  (C) 2001 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

#ifndef MPII_BSEND_H_INCLUDED

#define MPII_BSEND_H_INCLUDED

/* This file is separated out as it is used by the configure script to

 * find the Bsend overhead value. */

/*

 * Description of the Bsend data structures.

 *

 * Bsend is buffered send; a buffer, provided by the user, is used to store

 * both the user's message and information that my be needed to send that

 * message.  In addition, space within that buffer must be allocated, so

 * additional information is required to manage that space allocation.

 * In the following, the term "segment" denotes a fragment of the user buffer

 * that has been allocated either to free (unused) space or to a particular

 * user message.

 *

 * The following datastructures are used:

 *

 *  BsendMsg_t  - Describes a user message, including the values of tag

 *                and datatype (*could* be used incase the data is already

 *                contiguous; see below)

 *  BsendData_t - Describes a segment of the user buffer.  This data structure

 *                contains a BsendMsg_t for segments that contain a user

 *                message.  Each BsendData_t segment belongs to one of

 *                three lists: avail (unused and free), active (currently

 *                sending) and pending (contains a user message that has

 *                not begun sending because of some resource limit, such

 *                as no more MPID requests available).

 *  BsendBuffer - This global structure contains pointers to the user buffer

 *                and the three lists, along with the size of the user buffer.

 *

 */

/* Used to communication the type of bsend */

typedef enum {

    BSEND = 0,

    IBSEND = 1,

    BSEND_INIT = 2

} MPII_Bsend_kind_t;

struct MPIR_Request;

struct MPIR_Comm;

/* BsendMsg is used to hold all of the message particulars in case a

   request is not currently available */

typedef struct MPII_Bsend_msg {

    void *msgbuf;

    MPI_Aint count;

    MPI_Datatype dtype;

    int tag;

    struct MPIR_Comm *comm_ptr;

    int dest;

} MPII_Bsend_msg_t;

/* BsendData describes a bsend request */

typedef struct MPII_Bsend_data {

    size_t size;                /* size that is available for data */

    size_t total_size;          /* total size of this segment,

                                 * including all headers */

    struct MPII_Bsend_data *next, *prev;

    MPII_Bsend_kind_t kind;

    struct MPIR_Request *request;

    MPII_Bsend_msg_t msg;

    double alignpad;            /* make sure that the struct

                                 * shares double alignment */

} MPII_Bsend_data_t;

#endif /* MPII_BSEND_H_INCLUDED */