minix/servers/sched/utility.c

   1 /* This file contains some utility routines for SCHED.
   2  *
   3  * The entry points are:
   4  *   no_sys:            called for invalid system call numbers
   5  *   sched_isokendpt:   check the validity of an endpoint
   6  *   sched_isemtyendpt  check for validity and availability of endpoint slot
   7  *   accept_message     check whether message is allowed
   8  */
   9
  10 #include "sched.h"
  11 #include <machine/archtypes.h>
  12 #include <sys/resource.h> /* for PRIO_MAX & PRIO_MIN */
  13 #include "kernel/proc.h" /* for queue constants */
  14 #include "schedproc.h"
  15
  16 /*===========================================================================*
  17  *                              no_sys                                       *
  18  *===========================================================================*/
  19 int no_sys(int who_e, int call_nr)
  20 {
  21 /* A system call number not implemented by PM has been requested. */
  22   printf("SCHED: in no_sys, call nr %d from %d\n", call_nr, who_e);
  23   return(ENOSYS);
  24 }
  25
  26
  27 /*===========================================================================*
  28  *                              sched_isokendpt                              *
  29  *===========================================================================*/
  30 int sched_isokendpt(int endpoint, int *proc)
  31 {
  32         *proc = _ENDPOINT_P(endpoint);
  33         if (*proc < 0)
  34                 return (EBADEPT); /* Don't schedule tasks */
  35         if(*proc >= NR_PROCS)
  36                 return (EINVAL);
  37         if(endpoint != schedproc[*proc].endpoint)
  38                 return (EDEADEPT);
  39         if(!(schedproc[*proc].flags & IN_USE))
  40                 return (EDEADEPT);
  41         return (OK);
  42 }
  43
  44 /*===========================================================================*
  45  *                              sched_isemtyendpt                            *
  46  *===========================================================================*/
  47 int sched_isemtyendpt(int endpoint, int *proc)
  48 {
  49         *proc = _ENDPOINT_P(endpoint);
  50         if (*proc < 0)
  51                 return (EBADEPT); /* Don't schedule tasks */
  52         if(*proc >= NR_PROCS)
  53                 return (EINVAL);
  54         if(schedproc[*proc].flags & IN_USE)
  55                 return (EDEADEPT);
  56         return (OK);
  57 }
  58
  59 /*===========================================================================*
  60  *                              accept_message                               *
  61  *===========================================================================*/
  62 int accept_message(message *m_ptr)
  63 {
  64         /* accept all messages from PM and RS */
  65         switch (m_ptr->m_source) {
  66
  67                 case PM_PROC_NR:
  68                 case RS_PROC_NR:
  69                         return 1;
  70
  71         }
  72
  73         /* no other messages are allowable */
  74         return 0;
  75 }