compiler/alib/createtask.c

   1 /*
   2     Copyright © 1995-2007, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Create a new Amiga task
   6     Lang: english
   7 */
   8
   9 #include <exec/memory.h>
  10 #include <exec/execbase.h>
  11 #include <proto/exec.h>
  12
  13 struct newMemList
  14 {
  15   struct Node     nml_Node;
  16   UWORD           nml_NumEntries;
  17   struct MemEntry nml_ME[2];
  18 };
  19
  20 static const struct newMemList MemTemplate =
  21 {
  22     { 0, },
  23     2,
  24     {
  25         { { MEMF_CLEAR|MEMF_PUBLIC }, sizeof(struct Task) },
  26         { { MEMF_CLEAR             }, 0                   }
  27     }
  28 };
  29
  30
  31 /*****************************************************************************
  32
  33     NAME */
  34 #include <exec/tasks.h>
  35 #include <proto/alib.h>
  36
  37         struct Task * CreateTask (
  38
  39 /*  SYNOPSIS */
  40         STRPTR name,
  41         LONG   pri,
  42         APTR   initpc,
  43         ULONG  stacksize)
  44
  45 /*  FUNCTION
  46         Create a new task.
  47
  48     INPUTS
  49         name - Name of the task. The string is not copied. Note that
  50             task names' need not be unique.
  51         pri - The initial priority of the task (normally 0)
  52         initpc - The address of the first instruction of the
  53             task. In most cases, this is the address of a
  54             function.
  55         stacksize - The size of the stack for the task. Always
  56             keep in mind that the size of the stack must include
  57             the amount of stack which is needed by the routines
  58             called by the task.
  59
  60     RESULT
  61         A pointer to the new task or NULL on failure.
  62
  63     NOTES
  64
  65     EXAMPLE
  66
  67     BUGS
  68
  69     SEE ALSO
  70
  71     INTERNALS
  72
  73     HISTORY
  74
  75 ******************************************************************************/
  76 {
  77     struct Task     * newtask,
  78                     * task2;
  79     struct newMemList nml;
  80     struct MemList  * ml;
  81
  82     nml = MemTemplate;
  83
  84     stacksize = AROS_ALIGN(stacksize);
  85     nml.nml_ME[1].me_Length = stacksize;
  86
  87     if (NewAllocEntry((struct MemList *)&nml, &ml, NULL))
  88     {
  89         newtask = ml->ml_ME[0].me_Addr;
  90
  91         newtask->tc_Node.ln_Type = NT_TASK;
  92         newtask->tc_Node.ln_Pri  = pri;
  93         newtask->tc_Node.ln_Name = name;
  94
  95         newtask->tc_SPReg   = (APTR)((ULONG)ml->ml_ME[1].me_Addr + stacksize);
  96         newtask->tc_SPLower = ml->ml_ME[1].me_Addr;
  97         newtask->tc_SPUpper = newtask->tc_SPReg;
  98
  99         NewList (&newtask->tc_MemEntry);
 100         AddHead (&newtask->tc_MemEntry, (struct Node *)ml);
 101
 102         task2 = (struct Task *)AddTask (newtask, initpc, 0);
 103
 104         if (SysBase->LibNode.lib_Version>36 && !task2)
 105         {
 106             FreeEntry (ml);
 107             newtask = NULL;
 108         }
 109     }
 110     else
 111         newtask=NULL;
 112
 113     return newtask;
 114 } /* CreateTask */