rom/exec/alloctaskstorageslot.c

   1 /*
   2     Copyright © 2011-2012, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include <aros/debug.h>
   7
   8 #include "exec_intern.h"
   9 #include "exec_util.h"
  10 #include "taskstorage.h"
  11
  12 /*****************************************************************************
  13
  14     NAME */
  15 #include <proto/exec.h>
  16
  17         AROS_LH0(LONG, AllocTaskStorageSlot,
  18
  19 /*  LOCATION */
  20         struct ExecBase *, SysBase, 180, Exec)
  21
  22 /*  FUNCTION
  23         This function will allocate a slot in the taskstorage.
  24
  25     INPUTS
  26         None.
  27
  28     RESULT
  29         slot - The allocated slot, or 0 if no slot could be allocated.
  30
  31     NOTES
  32         After this function SetTaskStorageSlot(slot) may be used to store
  33         values with each slot. Data stored in a slot will be duplicated when
  34         a Task creates another Task. It is left up to the caller to implement
  35         a mechanism to check if this copied value is invalid.
  36
  37     EXAMPLE
  38
  39     BUGS
  40
  41     SEE ALSO
  42         FreeTaskStorageSlot(), GetTaskStorageSlot(), SetTaskStorageSlot()
  43
  44     INTERNALS
  45
  46 ******************************************************************************/
  47 {
  48     AROS_LIBFUNC_INIT
  49
  50     struct TaskStorageFreeSlot *tsfs;
  51     LONG slot;
  52     struct IntETask *iet = GetIntETask(FindTask(NULL));
  53
  54     if (!iet)
  55         return 0;
  56
  57     Forbid();
  58     tsfs = (struct TaskStorageFreeSlot *)
  59         GetHead(&PrivExecBase(SysBase)->TaskStorageSlots);
  60     if (!tsfs)
  61         Alert(AT_DeadEnd|AN_MemoryInsane);
  62
  63     slot = tsfs->FreeSlot;
  64
  65     D(bug("[TSS] Task 0x%p (%s): Allocated slot %d\n", FindTask(NULL), FindTask(NULL)->tc_Node.ln_Name, slot));
  66
  67     if (GetSucc(tsfs) == NULL)
  68     {
  69         /* Last element always points to highest element and is a new slot */
  70         tsfs->FreeSlot++;
  71     }
  72     else
  73     {
  74         Remove((struct Node *) tsfs);
  75         FreeMem(tsfs, sizeof(struct TaskStorageFreeSlot));
  76     }
  77     Permit();
  78
  79     return slot;
  80
  81     AROS_LIBFUNC_EXIT
  82 }