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 "schedproc.h"
  14
  15 /*===========================================================================*
  16  *                              no_sys                                       *
  17  *===========================================================================*/
  18 int no_sys(int who_e, int call_nr)
  19 {
  20 /* A system call number not implemented by PM has been requested. */
  21   printf("SCHED: in no_sys, call nr %d from %d\n", call_nr, who_e);
  22   return(ENOSYS);
  23 }
  24
  25
  26 /*===========================================================================*
  27  *                              sched_isokendpt                              *
  28  *===========================================================================*/
  29 int sched_isokendpt(int endpoint, int *proc)
  30 {
  31         *proc = _ENDPOINT_P(endpoint);
  32         if (*proc < 0)
  33                 return (EBADEPT); /* Don't schedule tasks */
  34         if(*proc >= NR_PROCS)
  35                 return (EINVAL);
  36         if(endpoint != schedproc[*proc].endpoint)
  37                 return (EDEADEPT);
  38         if(!(schedproc[*proc].flags & IN_USE))
  39                 return (EDEADEPT);
  40         return (OK);
  41 }
  42
  43 /*===========================================================================*
  44  *                              sched_isemtyendpt                            *
  45  *===========================================================================*/
  46 int sched_isemtyendpt(int endpoint, int *proc)
  47 {
  48         *proc = _ENDPOINT_P(endpoint);
  49         if (*proc < 0)
  50                 return (EBADEPT); /* Don't schedule tasks */
  51         if(*proc >= NR_PROCS)
  52                 return (EINVAL);
  53         if(schedproc[*proc].flags & IN_USE)
  54                 return (EDEADEPT);
  55         return (OK);
  56 }
  57
  58 /*===========================================================================*
  59  *                              accept_message                               *
  60  *===========================================================================*/
  61 int accept_message(message *m_ptr)
  62 {
  63         /* accept all messages from PM and RS */
  64         switch (m_ptr->m_source) {
  65
  66                 case PM_PROC_NR:
  67                 case RS_PROC_NR:
  68                         return 1;
  69
  70         }
  71
  72         /* no other messages are allowable */
  73         return 0;
  74 }