text: /*
   * Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
   *                         University Research and Technology
   *                         Corporation.  All rights reserved.
   * Copyright (c) 2004-2020 The University of Tennessee and The University
   *                         of Tennessee Research Foundation.  All rights
   *                         reserved.
   * Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
   *                         University of Stuttgart.  All rights reserved.
   * Copyright (c) 2004-2005 The Regents of the University of California.
   *                         All rights reserved.
   * $COPYRIGHT$
   *
   * Additional copyrights may follow
   *
   * $HEADER$
   */
  
  #ifndef MCA_BTL_TCP_HDR_H
  #define MCA_BTL_TCP_HDR_H
  
  
  #include "opal_config.h"
  #include "opal/mca/btl/base/base.h"
  #include "btl_tcp.h"
  
  BEGIN_C_DECLS
  
  /**
   * TCP header.
   */
  
  #define MCA_BTL_TCP_HDR_TYPE_SEND 1
  #define MCA_BTL_TCP_HDR_TYPE_PUT  2
  #define MCA_BTL_TCP_HDR_TYPE_GET  3
  #define MCA_BTL_TCP_HDR_TYPE_FIN  4
  /* The MCA_BTL_TCP_HDR_TYPE_FIN is a special kind of message sent during normal
   * connexion closing. Before the endpoint closes the socket, it performs a
   * 1-way handshake by sending a FIN message in the socket. This lets the other
   * end of the connexion discriminate between the case in which the peer has
   * closed intentionnally (e.g., during MPI_FINALIZE), or unintentionally (e.g.,
   * as the result of some transmission or process failure).
   * The process initiating the close sends the FIN message but does not wait
   * for a 2-way handshake and closes the socket immediately. Thus, the recipient
   * of a FIN message can simply close the socket and mark the endpoint as closed
   * without error, and without answering a FIN message itself.
   */
  
  struct mca_btl_tcp_hdr_t {
      mca_btl_base_header_t base;
      uint8_t  type;
      uint16_t count;
      uint32_t size;
  };
  typedef struct mca_btl_tcp_hdr_t mca_btl_tcp_hdr_t;
  
  #define MCA_BTL_TCP_HDR_HTON(hdr)     \
      do {                              \
          hdr.count = htons(hdr.count); \
          hdr.size = htonl(hdr.size);   \
      } while (0)
  
  #define MCA_BTL_TCP_HDR_NTOH(hdr)     \
      do {                              \
          hdr.count = ntohs(hdr.count); \
          hdr.size = ntohl(hdr.size);   \
      } while (0)
  
  END_C_DECLS
  #endif
  