rom/exec/getparenttaskstorageslot.c

   1 /*
   2     Copyright © 2014-2015, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include <aros/debug.h>
   7
   8 #include "taskstorage.h"
   9
  10 /*****************************************************************************
  11
  12     NAME */
  13 #include <proto/exec.h>
  14
  15         AROS_LH1(IPTR, GetParentTaskStorageSlot,
  16
  17 /*  LOCATION */
  18         AROS_LHA(LONG, id, D0),
  19         struct ExecBase *, SysBase, 186, Exec)
  20
  21 /*  FUNCTION
  22         Get a value for a task storage slot of parent task.
  23
  24     INPUTS
  25         id - slot ID returned from AllocTaskStorageSlot().
  26
  27     RESULT
  28         Value stored by SetTaskStorageSlot() on parent task, or
  29         (IPTR)NULL if the slot was never used.
  30
  31     NOTES
  32         Since you are accessing value of another task, the value
  33         might be invalid/freed by the time this function returns.
  34         To be sure value is still valid, call this function under
  35         Forbid().
  36
  37     EXAMPLE
  38
  39     BUGS
  40
  41     SEE ALSO
  42         AllocTaskStorageSlot(), FreeTaskStorageSlot(), SetTaskStorageSlot(),
  43         GetTaskStorageSlot()
  44
  45     INTERNALS
  46
  47 ******************************************************************************/
  48 {
  49     AROS_LIBFUNC_INIT
  50
  51     struct Task *ThisTask = GET_THIS_TASK;
  52     struct ETask *et = ThisTask ? GetETask(ThisTask) : NULL;
  53     IPTR result = (IPTR)NULL;
  54
  55     if (!et)
  56         return (IPTR)NULL;
  57
  58     Forbid(); /* Accessing other task's et_TaskStorage */
  59
  60     if (et->et_Parent)
  61         result = TaskGetStorageSlot(et->et_Parent, id);
  62
  63     Permit();
  64
  65     return result;
  66
  67     AROS_LIBFUNC_EXIT
  68 }