rom/dos/lockdoslist.c

   1 /*
   2     Copyright © 1995-2007, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc:
   6     Lang: english
   7 */
   8 #include <proto/exec.h>
   9 #include "dos_intern.h"
  10
  11 /*****************************************************************************
  12
  13     NAME */
  14 #include <proto/dos.h>
  15
  16         AROS_LH1(struct DosList *, LockDosList,
  17
  18 /*  SYNOPSIS */
  19         AROS_LHA(ULONG, flags, D1),
  20
  21 /*  LOCATION */
  22         struct DosLibrary *, DOSBase, 109, Dos)
  23
  24 /*  FUNCTION
  25         Waits until the desired dos lists are free then gets a lock on them.
  26         A handle is returned that can be used for FindDosEntry().
  27         Calls to this function nest, i.e. you must call UnLockDosList()
  28         as often as you called LockDosList(). Always lock all lists
  29         at once - do not try to get a lock on one of them then on another.
  30
  31     INPUTS
  32         flags - what lists to lock
  33
  34     RESULT
  35         Handle to the dos list. This is not a direct pointer
  36         to the first list element but to a pseudo element instead.
  37
  38     NOTES
  39
  40     EXAMPLE
  41
  42     BUGS
  43
  44     SEE ALSO
  45
  46     INTERNALS
  47
  48 *****************************************************************************/
  49 {
  50     AROS_LIBFUNC_INIT
  51     if(flags&LDF_WRITE)
  52         ObtainSemaphore(&DOSBase->dl_DosListLock);
  53     else
  54         ObtainSemaphoreShared(&DOSBase->dl_DosListLock);
  55     return (struct DosList *)&DOSBase->dl_DevInfo;
  56     AROS_LIBFUNC_EXIT
  57 } /* LockDosList */