rom/graphics/attemptlocklayerrom.c

   1 /*
   2     Copyright © 1995-2007, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Graphics function AttemptLockLayerRom()
   6     Lang: english
   7 */
   8 #include <graphics/clip.h>
   9 #include <graphics/layers.h>
  10 #include <proto/exec.h>
  11 #include <exec/types.h>
  12
  13 #include "graphics_intern.h"
  14
  15 /*****************************************************************************
  16
  17     NAME */
  18 #include <proto/graphics.h>
  19
  20         AROS_LH1(BOOL, AttemptLockLayerRom,
  21
  22 /*  SYNOPSIS */
  23         AROS_LHA(struct Layer *, l, A5),
  24
  25 /*  LOCATION */
  26         struct GfxBase *, GfxBase, 109, Graphics)
  27
  28 /*  FUNCTION
  29         Try to lock the current layer. If it is already locked this
  30         function will return FALSE, TRUE otherwise.
  31         If the layer could be locked successfully nesting will take place
  32         which means that for every successful locking of a layer
  33         UnlockLayerRom() has to be called for that layer to let other
  34         tasks access that layer.
  35
  36     INPUTS
  37         l - pointer to layer
  38
  39     RESULT
  40         TRUE  - layer is successfully locked for the task
  41         FALSE - layer could not be locked, it's locked by another task.
  42
  43     NOTES
  44
  45     EXAMPLE
  46
  47     BUGS
  48
  49     SEE ALSO
  50       LockLayerRom(), UnlockLayerRom()
  51
  52     INTERNALS
  53
  54     HISTORY
  55
  56 *****************************************************************************/
  57 {
  58   AROS_LIBFUNC_INIT
  59
  60   return AttemptSemaphore(&l->Lock);
  61
  62   AROS_LIBFUNC_EXIT
  63 } /* AttemptLockLayerRom */