rom/dos/lock.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Locks a file or directory.
   6     Lang: English
   7 */
   8
   9 #include <proto/exec.h>
  10 #include <utility/tagitem.h>
  11 #include <dos/dosextens.h>
  12 #include <dos/filesystem.h>
  13 #include <proto/dos.h>
  14 #include <proto/utility.h>
  15 #include "dos_intern.h"
  16
  17 #define  DEBUG  0
  18 #include <aros/debug.h>
  19
  20
  21 /*****************************************************************************
  22
  23     NAME */
  24 #include <proto/dos.h>
  25
  26         AROS_LH2(BPTR, Lock,
  27
  28 /*  SYNOPSIS */
  29         AROS_LHA(CONST_STRPTR, name,       D1),
  30         AROS_LHA(LONG,         accessMode, D2),
  31
  32 /*  LOCATION */
  33         struct DosLibrary *, DOSBase, 14, Dos)
  34
  35 /*  FUNCTION
  36         Gets a lock on a file or directory. There may be more than one
  37         shared lock on a file but only one if it is an exclusive one.
  38         Locked files or directories may not be deleted.
  39
  40     INPUTS
  41         name       - NUL terminated name of the file or directory.
  42         accessMode - One of SHARED_LOCK
  43                             EXCLUSIVE_LOCK
  44
  45     RESULT
  46         Handle to the file or directory or 0 if the object couldn't be locked.
  47         IoErr() gives additional information in that case.
  48
  49     NOTES
  50         The lock structure returned by this function is different
  51         from that of AmigaOS (in fact it is identical to a filehandle).
  52         Do not try to read any internal fields.
  53
  54 *****************************************************************************/
  55
  56 {
  57     AROS_LIBFUNC_INIT
  58     AROS_LIBBASE_EXT_DECL(struct DosLibrary *,DOSBase)
  59
  60     ASSERT_VALID_PTR(name);
  61
  62     /* Sanity check */
  63     if (name == NULL)
  64     {
  65         return NULL;
  66     }
  67
  68     BPTR con = NULL, ast = NULL;
  69     LONG error;
  70
  71     /* Get pointer to process structure */
  72         struct Process *
  73     me = (struct Process *)FindTask(NULL);
  74
  75     /* Create filehandle */
  76         struct FileHandle *
  77     ret = (struct FileHandle *)AllocDosObject(DOS_FILEHANDLE, NULL);
  78
  79     if (ret != NULL)
  80     {
  81         /* Get pointer to I/O request. Use stackspace for now. */
  82         struct IOFileSys iofs;
  83
  84         /* Prepare I/O request. */
  85         InitIOFS(&iofs, FSA_OPEN, DOSBase);
  86
  87         /* io_Args[0] is the name which is set by DoName(). */
  88         switch (accessMode)
  89         {
  90                 case EXCLUSIVE_LOCK:
  91                     iofs.io_Union.io_OPEN.io_FileMode = FMF_LOCK | FMF_READ;
  92                     con = me->pr_COS;
  93                     ast = me->pr_CES ? me->pr_CES : me->pr_COS;
  94                     break;
  95
  96                 case SHARED_LOCK:
  97                     iofs.io_Union.io_OPEN.io_FileMode = FMF_READ;
  98                     con = ast = me->pr_CIS;
  99                     break;
 100
 101                 default:
 102                     iofs.io_Union.io_OPEN.io_FileMode = accessMode;
 103                     con = ast = me->pr_CIS;
 104                     break;
 105         }
 106
 107 #define iofs_SetDeviceUnit(_iofs, _fh) \
 108 { \
 109      (_iofs).IOFS.io_Device = ((struct FileHandle *)BADDR((_fh)))->fh_Device; \
 110      (_iofs).IOFS.io_Unit   = ((struct FileHandle *)BADDR((_fh)))->fh_Unit; \
 111 }
 112
 113         if(!Stricmp(name, "IN:") || !Stricmp(name, "STDIN:"))
 114         {
 115             iofs_SetDeviceUnit(iofs, me->pr_CIS);
 116
 117             iofs.io_Union.io_OPEN_FILE.io_Filename = "";
 118
 119             DosDoIO(&iofs.IOFS);
 120
 121             error = me->pr_Result2 = iofs.io_DosError;
 122         }
 123         else if(!Stricmp(name, "OUT:") || !Stricmp(name, "STDOUT:"))
 124         {
 125             iofs_SetDeviceUnit(iofs, me->pr_COS);
 126
 127             iofs.io_Union.io_OPEN_FILE.io_Filename = "";
 128
 129             DosDoIO(&iofs.IOFS);
 130
 131             error = me->pr_Result2 = iofs.io_DosError;
 132         }
 133         else if(!Stricmp(name, "ERR:") || !Stricmp(name, "STDERR:"))
 134         {
 135             if (NULL != me->pr_CES)
 136             {
 137                 iofs_SetDeviceUnit(iofs, me->pr_CES);
 138             }
 139             else
 140             {
 141                 iofs_SetDeviceUnit(iofs, me->pr_COS);
 142             }
 143
 144             iofs.io_Union.io_OPEN_FILE.io_Filename = "";
 145
 146             DosDoIO(&iofs.IOFS);
 147
 148             error = me->pr_Result2 = iofs.io_DosError;
 149         }
 150         else if(!Stricmp(name, "CONSOLE:"))
 151         {
 152             iofs_SetDeviceUnit(iofs, con);
 153
 154             iofs.io_Union.io_OPEN_FILE.io_Filename = "";
 155
 156             DosDoIO(&iofs.IOFS);
 157
 158             error = me->pr_Result2 = iofs.io_DosError;
 159         }
 160         else if(!Stricmp(name, "*"))
 161         {
 162             iofs_SetDeviceUnit(iofs, ast);
 163
 164             iofs.io_Union.io_OPEN_FILE.io_Filename = "";
 165
 166             DosDoIO(&iofs.IOFS);
 167
 168             error = me->pr_Result2 = iofs.io_DosError;
 169         }
 170         else
 171         {
 172             error = DoName(&iofs, name, DOSBase);
 173         }
 174
 175         if (!error)
 176         {
 177             ret->fh_Device = iofs.IOFS.io_Device;
 178             ret->fh_Unit   = iofs.IOFS.io_Unit;
 179
 180             return MKBADDR(ret);
 181         }
 182         else
 183         {
 184             FreeDosObject(DOS_FILEHANDLE, ret);
 185         }
 186     }
 187     else
 188     {
 189         SetIoErr(ERROR_NO_FREE_STORE);
 190     }
 191
 192     return NULL;
 193
 194     AROS_LIBFUNC_EXIT
 195 } /* Lock */