rom/exec/alloctaskstorageslot.c

   1 /*
   2     Copyright © 2011, 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(int, 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         The allocated slot, 0 if no slot could be allocated.
  30
  31     NOTES
  32         After this function FindTask(NULL)->tc_UnionETask.tc_TaskStorage[slot]
  33         may be used to store values with each slot. Data stored in a slot
  34         will be duplicated when a Task creates another Task. It is left up to the
  35         to implement a mechanism to check if this copied value is invalid.
  36
  37     EXAMPLE
  38
  39     BUGS
  40
  41     SEE ALSO
  42         FreeTaskStorageSlot()
  43
  44     INTERNALS
  45
  46 ******************************************************************************/
  47 {
  48     AROS_LIBFUNC_INIT
  49
  50     struct TaskStorageFreeSlot *tsfs = (struct TaskStorageFreeSlot *)GetHead(&PrivExecBase(SysBase)->TaskStorageSlots);
  51     int slot;
  52     struct Task *t;
  53
  54     if (!tsfs)
  55         Alert(AT_DeadEnd|AN_MemoryInsane);
  56
  57     slot = tsfs->FreeSlot;
  58
  59     D(bug("[TSS] Task 0x%p (%s): Allocated slot %d\n", FindTask(NULL), FindTask(NULL)->tc_Node.ln_Name, slot));
  60
  61     if ((slot + 1)*sizeof(IPTR) > PrivExecBase(SysBase)->TaskStorageSize)
  62     {
  63         t = FindTask(NULL);
  64
  65         if (!Exec_ExpandTS(t, SysBase))
  66             return 0;
  67     }
  68
  69     if (GetSucc(tsfs) == NULL)
  70     {
  71         /* Last element always points to highest element and is a new slot */
  72         tsfs->FreeSlot++;
  73     }
  74     else
  75     {
  76         Remove((struct Node *)tsfs);
  77         FreeMem(tsfs, sizeof(struct TaskStorageFreeSlot));
  78
  79         /* Clean previous values in slot on all tasks */
  80         Forbid();
  81         ForeachNode(&SysBase->TaskReady, t)
  82         {
  83             if (t->tc_Flags & TF_ETASK)
  84                 t->tc_UnionETask.tc_TaskStorage[slot] = (IPTR)0;
  85         }
  86         ForeachNode(&SysBase->TaskWait, t)
  87         {
  88             if (t->tc_Flags & TF_ETASK)
  89                 t->tc_UnionETask.tc_TaskStorage[slot] = (IPTR)0;
  90         }
  91         Permit();
  92     }
  93
  94     return slot;
  95
  96     AROS_LIBFUNC_EXIT
  97 }