rom/exec/addtask.c

   1 /*
   2     Copyright © 1995-2011, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Add a task.
   6     Lang: english
   7 */
   8
   9 #include <exec/execbase.h>
  10 #include <exec/memory.h>
  11 #include <aros/debug.h>
  12 #include <aros/libcall.h>
  13 #include <proto/exec.h>
  14
  15 #include "etask.h"
  16 #include "exec_intern.h"
  17 #include "exec_util.h"
  18 #include "exec_debug.h"
  19
  20 /*****************************************************************************
  21
  22     NAME */
  23
  24         AROS_LH3(APTR, AddTask,
  25
  26 /*  SYNOPSIS */
  27         AROS_LHA(struct Task *,     task,      A1),
  28         AROS_LHA(APTR,              initialPC, A2),
  29         AROS_LHA(APTR,              finalPC,   A3),
  30
  31 /*  LOCATION */
  32         struct ExecBase *, SysBase, 47, Exec)
  33
  34 /*  FUNCTION
  35         Add a new task to the system. If the new task has the highest
  36         priority of all and task switches are allowed it will be started
  37         immediately.
  38
  39         You must initialise certain fields, and allocate a stack before
  40         calling this function. The fields that must be initialised are:
  41         tc_SPLower, tc_SPUpper, tc_SPReg, and the tc_Node structure.
  42
  43         If any other fields are initialised to zero, then they will be
  44         filled in with the system defaults.
  45
  46         The value of tc_SPReg will be used as the location for the stack
  47         pointer. You can place any arguments you wish to pass to the Task
  48         onto the stack before calling AddTask(). However note that you may
  49         need to consider the stack direction on your processor.
  50
  51         Memory can be added to the tc_MemEntry list and will be freed when
  52         the task dies. The new task's registers are set to 0.
  53
  54     INPUTS
  55         task      - Pointer to task structure.
  56         initialPC - Entry point for the new task.
  57         finalPC   - Routine that is called if the initialPC() function
  58                     returns. A NULL pointer installs the default finalizer.
  59
  60     RESULT
  61         The address of the new task or NULL if the operation failed.
  62
  63     NOTES
  64         Use of AddTask() is deprecated on AROS; NewAddTask() should be used
  65         instead. AddTask() is only retained for backwards compatiblity.
  66
  67         No proper initialization for alternative stack is done so alternative
  68         stack can't be in tasks started with AddTask(). This means that on
  69         some archs no shared library functions can be called.
  70
  71     EXAMPLE
  72
  73     BUGS
  74
  75     SEE ALSO
  76         RemTask(), NewAddTask()
  77
  78     INTERNALS
  79
  80 ******************************************************************************/
  81 {
  82     AROS_LIBFUNC_INIT
  83
  84     struct Task *t;
  85
  86     DADDTASK("AddTask (0x%p (\"%s\"), 0x%p, 0x%p)", task, task->tc_Node.ln_Name, initialPC, finalPC);
  87
  88     t = NewAddTask(task, initialPC, finalPC, NULL);
  89
  90     ReturnPtr ("AddTask", struct Task *, t);
  91
  92     AROS_LIBFUNC_EXIT
  93 } /* AddTask */