rom/exec/reschedule.c

   1 /*
   2     Copyright © 1995-2013, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Enforce task rescheduling
   6     Lang: english
   7 */
   8
   9 #include <exec/execbase.h>
  10 #include <aros/libcall.h>
  11 #include <aros/atomic.h>
  12 #include <hardware/intbits.h>
  13 #include <proto/kernel.h>
  14
  15 #include "chipset.h"
  16 #include "exec_intern.h"
  17
  18 /*****************************************************************************
  19
  20     NAME */
  21 #include <proto/exec.h>
  22
  23         AROS_LH0(void, Reschedule,
  24
  25 /*  SYNOPSIS */
  26
  27 /*  LOCATION */
  28         struct ExecBase *, SysBase, 8, Exec)
  29
  30 /*  FUNCTION
  31         Give up the CPU time to other tasks (if there are any).
  32
  33     INPUTS
  34         None
  35
  36     RESULT
  37         None
  38
  39     NOTES
  40         This function was private in AmigaOS(tm) up to v3.1. There's no guarantee
  41         that it will continue to exist in other systems.
  42
  43     EXAMPLE
  44
  45     BUGS
  46
  47     SEE ALSO
  48
  49     INTERNALS
  50
  51     HISTORY
  52
  53 ******************************************************************************/
  54 {
  55     AROS_LIBFUNC_INIT
  56
  57     UWORD oldAttnSwitch = SysBase->AttnResched & ARF_AttnSwitch;
  58
  59     AROS_ATOMIC_OR(SysBase->AttnResched, ARF_AttnSwitch);       /* Set scheduling attention */
  60
  61     if (SysBase->TDNestCnt < 0)                 /* If task switching enabled */
  62     {
  63         if (SysBase->IDNestCnt < 0)             /* And interrupts enabled */
  64         {
  65             D(bug("[Reschedule] Calling scheduler, KernelBase 0x%p\n", KernelBase));
  66             KrnSchedule();                      /* Call scheduler */
  67         }
  68         else if (!oldAttnSwitch)
  69         {
  70             /*
  71              * Interrupts are disabled and there was no pending switch before us.
  72              * Tag the software interrupt to be executed immediately after Enable().
  73              */
  74             CUSTOM_CAUSE(INTF_SOFTINT);
  75         }
  76     }
  77
  78     AROS_LIBFUNC_EXIT
  79 } /* Reschedule */