rom/exec/obtainsemaphore.c

   1 /*
   2     Copyright © 1995-2011, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Lock a semaphore.
   6     Lang: english
   7 */
   8
   9 #include <exec/semaphores.h>
  10 #include <aros/atomic.h>
  11
  12 #include "exec_intern.h"
  13 #include "exec_util.h"
  14 #include "semaphores.h"
  15
  16 /*****************************************************************************/
  17 #undef  Exec
  18 #ifdef UseExecstubs
  19 #    define Exec _Exec
  20 #endif
  21
  22 /*    NAME */
  23         #include <proto/exec.h>
  24
  25         AROS_LH1(void, ObtainSemaphore,
  26
  27 /*    SYNOPSIS */
  28         AROS_LHA(struct SignalSemaphore *, sigSem, A0),
  29
  30 /*    LOCATION */
  31         struct ExecBase *, SysBase, 94, Exec)
  32
  33 /*    FUNCTION
  34         Obtain an exclusive lock on a semaphore. If the semaphore is already
  35         in use by another task this function will wait until the semaphore
  36         becomes free.
  37
  38     INPUTS
  39         sigSem - Pointer to semaphore structure
  40
  41     RESULT
  42
  43     NOTES
  44         This function preserves all registers.
  45
  46     EXAMPLE
  47
  48     BUGS
  49
  50     SEE ALSO
  51         ReleaseSemaphore()
  52
  53     INTERNALS
  54
  55 *****************************************************************************/
  56 {
  57 #undef  Exec
  58
  59     AROS_LIBFUNC_INIT
  60
  61     struct TraceLocation tp = CURRENT_LOCATION("ObtainSemaphore");
  62     struct Task *me = FindTask(NULL);
  63
  64     InternalObtainSemaphore(sigSem, me, &tp, SysBase);
  65
  66     AROS_LIBFUNC_EXIT
  67 } /* ObtainSemaphore */