rom/dos/lockrecord.c

   1 /*
   2     Copyright © 1995-2007, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc:
   6     Lang: English
   7 */
   8
   9 #include "dos_intern.h"
  10 #include <dos/filesystem.h>
  11 #include <proto/exec.h>
  12
  13 /*****************************************************************************
  14
  15     NAME */
  16 #include <proto/dos.h>
  17
  18         AROS_LH5(BOOL, LockRecord,
  19
  20 /*  SYNOPSIS */
  21         AROS_LHA(BPTR , fh, D1),
  22         AROS_LHA(ULONG, offset, D2),
  23         AROS_LHA(ULONG, length, D3),
  24         AROS_LHA(ULONG, mode, D4),
  25         AROS_LHA(ULONG, timeout, D5),
  26
  27 /*  LOCATION */
  28         struct DosLibrary *, DOSBase, 45, Dos)
  29
  30 /*  FUNCTION
  31
  32     Lock a portion of a file for exclusive access. A timeout may be specified
  33     which is the maximum amount of time to wait for the record to be available.
  34
  35     INPUTS
  36
  37     fh       --  file handle for the file to lock a record of
  38     offset   --  starting position of the lock
  39     length   --  length of the record in bytes
  40     mode     --  lock type
  41     timeout  --  timeout interval measured in ticks (may be 0)
  42
  43     RESULT
  44
  45     Success/failure indicator.
  46
  47     NOTES
  48
  49     Record locks are cooperative, meaning that they only affect other calls
  50     to LockRecord().
  51
  52     EXAMPLE
  53
  54     BUGS
  55
  56     SEE ALSO
  57
  58     LockRecords(), UnLockRecord()
  59
  60     INTERNALS
  61
  62 *****************************************************************************/
  63 {
  64     AROS_LIBFUNC_INIT
  65
  66     struct IOFileSys iofs;
  67     struct FileHandle *fileH = fh;
  68
  69     if (fh == NULL)
  70     {
  71         return DOSFALSE;
  72     }
  73
  74     InitIOFS(&iofs, FSA_LOCK_RECORD, DOSBase);
  75
  76     iofs.IOFS.io_Device = fileH->fh_Device;
  77     iofs.IOFS.io_Unit = fileH->fh_Unit;
  78
  79     iofs.io_Union.io_RECORD.io_Offset = offset;
  80     iofs.io_Union.io_RECORD.io_Size = length;
  81     iofs.io_Union.io_RECORD.io_RecordMode = mode;
  82     iofs.io_Union.io_RECORD.io_Timeout = timeout;
  83
  84     DosDoIO(&iofs.IOFS);
  85
  86     SetIoErr(iofs.io_DosError);
  87
  88     if (iofs.io_DosError != 0)
  89     {
  90         return DOSFALSE;
  91     }
  92
  93     return DOSTRUE;
  94
  95     AROS_LIBFUNC_EXIT
  96 } /* LockRecord */