root/ompi/mca/io/romio321/romio/adio/ad_nfs/ad_nfs_getsh.c

DEFINITIONS

1. ADIOI_NFS_Get_shared_fp

   1 /* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */
   2 /* 
   3  *
   4  *   Copyright (C) 1997 University of Chicago. 
   5  *   See COPYRIGHT notice in top-level directory.
   6  */
   7 
   8 #include "ad_nfs.h"
   9 
  10 /* returns the current location of the shared_fp in terms of the
  11    no. of etypes relative to the current view, and also increments the
  12    shared_fp by the number of etypes to be accessed (incr) in the read
  13    or write following this function. */
  14 
  15 void ADIOI_NFS_Get_shared_fp(ADIO_File fd, ADIO_Offset incr, ADIO_Offset *shared_fp,
  16                          int *error_code)
  17 {
  18     ADIO_Offset new_fp;
  19     ssize_t err;
  20     MPI_Comm dupcommself;
  21     static char myname[] = "ADIOI_NFS_GET_SHARED_FP";
  22 
  23     if (fd->shared_fp_fd == ADIO_FILE_NULL) {
  24         MPI_Comm_dup(MPI_COMM_SELF, &dupcommself);
  25         fd->shared_fp_fd = ADIO_Open(MPI_COMM_SELF, dupcommself,
  26                                      fd->shared_fp_fname, 
  27                                      fd->file_system,
  28                                      fd->fns,
  29                                      ADIO_CREATE | ADIO_RDWR | ADIO_DELETE_ON_CLOSE, 
  30                                      0, MPI_BYTE, MPI_BYTE, MPI_INFO_NULL, 
  31                                      ADIO_PERM_NULL, error_code);
  32         if (*error_code != MPI_SUCCESS) return;
  33         *shared_fp = 0;
  34         ADIOI_WRITE_LOCK(fd->shared_fp_fd, 0, SEEK_SET, sizeof(ADIO_Offset));
  35 #ifdef ADIOI_MPE_LOGGING
  36         MPE_Log_event( ADIOI_MPE_read_a, 0, NULL );
  37 #endif
  38         err = read(fd->shared_fp_fd->fd_sys, shared_fp, sizeof(ADIO_Offset));
  39 #ifdef ADIOI_MPE_LOGGING
  40         MPE_Log_event( ADIOI_MPE_read_b, 0, NULL );
  41 #endif
  42         /* if the file is empty, the above read may return error
  43            (reading beyond end of file). In that case, shared_fp = 0, 
  44            set above, is the correct value. */
  45     }
  46     else {
  47         ADIOI_WRITE_LOCK(fd->shared_fp_fd, 0, SEEK_SET, sizeof(ADIO_Offset));
  48 
  49 #ifdef ADIOI_MPE_LOGGING
  50         MPE_Log_event( ADIOI_MPE_lseek_a, 0, NULL );
  51 #endif
  52         err = lseek(fd->shared_fp_fd->fd_sys, 0, SEEK_SET);
  53 #ifdef ADIOI_MPE_LOGGING
  54         MPE_Log_event( ADIOI_MPE_lseek_b, 0, NULL );
  55 #endif
  56         if (err == 0) {
  57 #ifdef ADIOI_MPE_LOGGING
  58             MPE_Log_event( ADIOI_MPE_read_a, 0, NULL );
  59 #endif
  60             err = read(fd->shared_fp_fd->fd_sys, shared_fp,
  61                        sizeof(ADIO_Offset));
  62 #ifdef ADIOI_MPE_LOGGING
  63             MPE_Log_event( ADIOI_MPE_read_b, 0, NULL );
  64 #endif
  65         }
  66         if (err == -1) {
  67             ADIOI_UNLOCK(fd->shared_fp_fd, 0, SEEK_SET, sizeof(ADIO_Offset));
  68             *error_code = MPIO_Err_create_code(MPI_SUCCESS,
  69                                                MPIR_ERR_RECOVERABLE, myname,
  70                                                __LINE__, MPI_ERR_IO, "**io",
  71                                                "**io %s", strerror(errno));
  72             return;
  73         }
  74     }
  75 
  76     if (incr == 0) {goto done;}
  77 
  78     new_fp = *shared_fp + incr;
  79 
  80 #ifdef ADIOI_MPE_LOGGING
  81     MPE_Log_event( ADIOI_MPE_lseek_a, 0, NULL );
  82 #endif
  83     err = lseek(fd->shared_fp_fd->fd_sys, 0, SEEK_SET);
  84 #ifdef ADIOI_MPE_LOGGING
  85     MPE_Log_event( ADIOI_MPE_lseek_b, 0, NULL );
  86 #endif
  87     if (err == 0) {
  88 #ifdef ADIOI_MPE_LOGGING
  89         MPE_Log_event( ADIOI_MPE_write_a, 0, NULL );
  90 #endif
  91         err = write(fd->shared_fp_fd->fd_sys, &new_fp, sizeof(ADIO_Offset));
  92 #ifdef ADIOI_MPE_LOGGING
  93         MPE_Log_event( ADIOI_MPE_write_b, 0, NULL );
  94 #endif
  95     }
  96 done:
  97     ADIOI_UNLOCK(fd->shared_fp_fd, 0, SEEK_SET, sizeof(ADIO_Offset));
  98     if (err == -1) {
  99         *error_code = MPIO_Err_create_code(MPI_SUCCESS, MPIR_ERR_RECOVERABLE,
 100                                            myname, __LINE__, MPI_ERR_IO,
 101                                            "**io",
 102                                            "**io %s", strerror(errno));
 103     }
 104     else *error_code = MPI_SUCCESS;
 105 }