rom/exec/reschedule.c

   1 /*
   2     Copyright © 1995-2017, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Enforce task rescheduling
   6     Lang: english
   7 */
   8
   9 #define DEBUG 0
  10
  11 #include <exec/execbase.h>
  12 #include <aros/libcall.h>
  13 #include <aros/atomic.h>
  14 #include <hardware/intbits.h>
  15
  16 #include "chipset.h"
  17 #include "exec_intern.h"
  18
  19 /*****************************************************************************
  20
  21     NAME */
  22 #include <proto/exec.h>
  23
  24         AROS_LH0(void, Reschedule,
  25
  26 /*  SYNOPSIS */
  27
  28 /*  LOCATION */
  29         struct ExecBase *, SysBase, 8, Exec)
  30
  31 /*  FUNCTION
  32         Give up the CPU time to other tasks (if there are any).
  33
  34     INPUTS
  35         None
  36
  37     RESULT
  38         None
  39
  40     NOTES
  41         This function was private in AmigaOS(tm) up to v3.1. There's no guarantee
  42         that it will continue to exist in other systems.
  43
  44     EXAMPLE
  45
  46     BUGS
  47
  48     SEE ALSO
  49
  50     INTERNALS
  51
  52     HISTORY
  53
  54 ******************************************************************************/
  55 {
  56     AROS_LIBFUNC_INIT
  57
  58     BOOL switchpending = FLAG_SCHEDSWITCH_ISSET;
  59
  60     FLAG_SCHEDSWITCH_SET;       /* Set scheduling attention */
  61
  62     if (TDNESTCOUNT_GET < 0)                 /* If task switching enabled */
  63     {
  64         if (IDNESTCOUNT_GET < 0)             /* And interrupts enabled */
  65         {
  66             D(bug("[Reschedule] Calling scheduler, KernelBase 0x%p\n", KernelBase);)
  67             KrnSchedule();                      /* Call scheduler */
  68         }
  69         else if (!switchpending)
  70         {
  71             /*
  72              * Interrupts are disabled and there was no pending switch before us.
  73              * Tag the software interrupt to be executed immediately after Enable().
  74              */
  75             CUSTOM_CAUSE(INTF_SOFTINT);
  76         }
  77     }
  78
  79     AROS_LIBFUNC_EXIT
  80 } /* Reschedule */