bgui/stkext.c

   1 /*
   2  *  @(#) $Header$
   3  *
   4  *  BGUI library
   5  *  stkext.c
   6  *  Generic stack extension routines.
   7  *
   8  *  Copyright © 2011, The AROS Development Team.
   9  *  (C) Janne Jalkanen 1998
  10  *  (C) Copyright 1998 Manuel Lemos.
  11  *  (C) Copyright 1996-1997 Ian J. Einman.
  12  *  (C) Copyright 1993-1996 Jaba Development.
  13  *  (C) Copyright 1993-1996 Jan van den Baard.
  14  *  All Rights Reserved.
  15  *
  16  *  Converted by hand from stkext.asm
  17  *
  18  */
  19
  20 #include <proto/intuition.h>
  21 #include <proto/exec.h>
  22
  23 #define STKMARGIN       2048    // When should we start worrying about the stack?
  24 #define STKSIZE         16384   // Allocate this much stack space
  25 #define CTLBLOCK        sizeof(StackSwapStruct)
  26
  27 extern struct Task *InputDevice;
  28 extern APTR InputStack;
  29
  30 /*****************************************************************************
  31  *
  32  *  EnsureStack allocates a handle, which must be returned back to RevertStack
  33  *
  34  *  Registers preserved: all, except d0 and sp
  35  */
  36 APTR EnsureStack(VOID)
  37 {
  38     struct Task *task;
  39     struct EasyStruct easy = {
  40         .es_StructSize = sizeof(struct EasyStruct),
  41         .es_Flags = 0,
  42         .es_Title = "BGUI Stack Overflow",
  43         .es_TextFormat = "The \"%s\" process is out of stack space.",
  44         .es_GadgetFormat = "Suspend",
  45     };
  46 //  Figure out our address
  47     task = FindTask(NULL);
  48
  49 //  Calculate current stack left and check if it is within
  50 //  allowed limits
  51
  52     if ((IPTR)&task >= ((IPTR)task->tc_SPLower + STKMARGIN))
  53         return NULL;
  54
  55 // It's not safe to do on-the-fly stack extensions
  56 // under AROS.
  57     for (;;)
  58         EasyRequest(NULL, &easy, NULL, task->tc_Node.ln_Name);
  59 }
  60
  61 /*****************************************************************************
  62  *
  63  *   This function returns the stack back to free memory pool.
  64  *   Safe to call with NULL args
  65  *
  66  *   Registers destroyed: d0/a0/a1/a7
  67  */
  68
  69 VOID RevertStack(APTR stack)
  70 {
  71 }
  72
  73 /*******************************************************************************
  74  *
  75  *   This function allocates memory for the input.device stack extension,
  76  *   which is allocated only during library initialization.
  77  */
  78
  79 VOID InitInputStack(VOID)
  80 {
  81 }
  82
  83 VOID FreeInputStack(VOID)
  84 {
  85 }