arch/i386-pc/exec/reschedule.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc:
   6     Lang: english
   7 */
   8
   9 #include <exec/types.h>
  10 #include <exec/execbase.h>
  11 #include <aros/libcall.h>
  12 #include <aros/atomic.h>
  13
  14 void Exec_Permit_Supervisor();
  15
  16 /*****i***********************************************************************
  17
  18     NAME */
  19 #include <proto/exec.h>
  20
  21         AROS_LH1(void, Reschedule,
  22
  23 /*  SYNOPSIS */
  24         AROS_LHA(struct Task *, task, A0),
  25
  26 /*  LOCATION */
  27         struct ExecBase *, SysBase, 8, Exec)
  28
  29 /*  FUNCTION
  30         Reschedule will place the task into one of Exec's internal task
  31         lists. Which list it is placed in will depend upon whether the
  32         task is ready to run, or whether it is waiting for an external
  33         event to awaken it.
  34
  35         It is possible that in the future, more efficient schedulers
  36         will be implemented. In which case this is the function that they
  37         need to implement.
  38
  39         You should not do any costly calculations since you will be
  40         running in interrupt mode.
  41
  42     INPUTS
  43         task    -   The task to insert into the list.
  44
  45     RESULT
  46         The task will be inserted into one of Exec's task lists.
  47
  48     NOTES
  49         Not actually complete yet. Some of the task states don't have any
  50         supplied action.
  51
  52     EXAMPLE
  53
  54     BUGS
  55         Only in relation to the comments within about low-priority tasks
  56         not getting any processor time.
  57
  58     SEE ALSO
  59
  60     INTERNALS
  61
  62     HISTORY
  63
  64 ******************************************************************************/
  65 {
  66     AROS_LIBFUNC_INIT
  67
  68     UBYTE flag = SysBase->AttnResched;          /* Save state of scheduling attention */
  69
  70     AROS_ATOMIC_OR(SysBase->AttnResched, 0x80); /* Set scheduling attention */
  71
  72     if (SysBase->TDNestCnt < 0)                 /* If task switching enabled */
  73     {
  74         if (SysBase->IDNestCnt < 0)             /* And interrupts enabled */
  75         {
  76             Supervisor((ULONG_FUNC)Exec_Permit_Supervisor);
  77         }
  78         else if (!(flag & 0x80))                /* Generate software interrupt */
  79         {
  80 #if 0
  81 #warning: "This is wrong!!!!!!!! It should cause the software interrupt only once interrupts are enabled again"
  82 #warning  "but this jumps directly to software interrupt, no matter if interrupts are enabled or not"
  83             __asm__ ("movl $-3,%eax\n\tint $0x80");
  84 #endif
  85         }
  86     }
  87
  88     AROS_LIBFUNC_EXIT
  89 } /* Reschedule */