workbench/libs/realtime/lockrealtime.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc:
   6     Lang: English
   7 */
   8
   9 #include <proto/exec.h>
  10 #include "realtime_intern.h"
  11
  12 /*****************************************************************************
  13
  14     NAME */
  15 #include <libraries/realtime.h>
  16
  17     AROS_LH1(APTR, LockRealTime,
  18
  19 /*  SYNOPSIS */
  20
  21         AROS_LHA(ULONG, lockType, D0),
  22
  23 /*  LOCATION */
  24
  25         struct Library *, RealTimeBase, 5, RealTime)
  26
  27 /*  FUNCTION
  28
  29     Lock a RealTime.library internal semaphore.
  30
  31     INPUTS
  32
  33     lockType  --  The type of lock to aquire, see <libraries/realtime.h> for
  34                   further information.
  35
  36     RESULT
  37
  38     A handle to pass to UnlockRealTime() to unlock the semaphore. If 'lockType'
  39     is invalid, NULL is returned.
  40
  41     NOTES
  42
  43     EXAMPLE
  44
  45     BUGS
  46
  47     SEE ALSO
  48
  49     UnlockRealTime()
  50
  51     INTERNALS
  52
  53     HISTORY
  54
  55     26.7.99  SDuvan  implemented
  56
  57 ******************************************************************************/
  58
  59 {
  60     AROS_LIBFUNC_INIT
  61
  62     if(lockType >= RT_MAXLOCK)
  63         return NULL;
  64
  65     ObtainSemaphore(&GPB(RealTimeBase)->rtb_Locks[lockType]);
  66
  67     return (APTR)(&GPB(RealTimeBase)->rtb_Locks[lockType]);
  68
  69     AROS_LIBFUNC_EXIT
  70 } /* LockRealTime */