rom/exec/addtask.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Add a task.
   6     Lang: english
   7 */
   8 #include <exec/execbase.h>
   9 #include <exec/memory.h>
  10 #include <aros/libcall.h>
  11 #include <aros/config.h>
  12 #include <proto/exec.h>
  13 #include "etask.h"
  14 #include "exec_util.h"
  15
  16 #include "exec_debug.h"
  17 #ifndef DEBUG_AddTask
  18 #   define DEBUG_AddTask 0
  19 #endif
  20 #undef DEBUG
  21 #if DEBUG_AddTask
  22 #   define DEBUG 1
  23 #endif
  24 #include <aros/debug.h>
  25
  26 /*****************************************************************************
  27
  28     NAME */
  29
  30         AROS_LH3(APTR, AddTask,
  31
  32 /*  SYNOPSIS */
  33         AROS_LHA(struct Task *,     task,      A1),
  34         AROS_LHA(APTR,              initialPC, A2),
  35         AROS_LHA(APTR,              finalPC,   A3),
  36
  37 /*  LOCATION */
  38         struct ExecBase *, SysBase, 47, Exec)
  39
  40 /*  FUNCTION
  41         Add a new task to the system. If the new task has the highest
  42         priority of all and task switches are allowed it will be started
  43         immediately.
  44
  45         You must initialise certain fields, and allocate a stack before
  46         calling this function. The fields that must be initialised are:
  47         tc_SPLower, tc_SPUpper, tc_SPReg, and the tc_Node structure.
  48
  49         If any other fields are initialised to zero, then they will be
  50         filled in with the system defaults.
  51
  52         The value of tc_SPReg will be used as the location for the stack
  53         pointer. You can place any arguments you wish to pass to the Task
  54         onto the stack before calling AddTask(). However note that you may
  55         need to consider the stack direction on your processor.
  56
  57         Memory can be added to the tc_MemEntry list and will be freed when
  58         the task dies. The new task's registers are set to 0.
  59
  60     INPUTS
  61         task      - Pointer to task structure.
  62         initialPC - Entry point for the new task.
  63         finalPC   - Routine that is called if the initialPC() function
  64                     returns. A NULL pointer installs the default finalizer.
  65
  66     RESULT
  67         The address of the new task or NULL if the operation failed.
  68
  69     NOTES
  70
  71     EXAMPLE
  72
  73     BUGS
  74
  75     SEE ALSO
  76         RemTask()
  77
  78     INTERNALS
  79
  80 ******************************************************************************/
  81 {
  82     AROS_LIBFUNC_INIT
  83
  84     struct Task *t;
  85
  86     D(bug("Call AddTask (%08lx (\"%s\"), %08lx, %08lx)\n"
  87         , task
  88         , task->tc_Node.ln_Name
  89         , initialPC
  90         , finalPC
  91     ));
  92
  93     t = NewAddTask(task, initialPC, finalPC, NULL);
  94
  95     ReturnPtr ("AddTask", struct Task *, t);
  96
  97     AROS_LIBFUNC_EXIT
  98 } /* AddTask */