lib/libsys/sched_start.c

   1 #include "syslib.h"
   2 #include <assert.h>
   3 #include <machine/archtypes.h>
   4 #include <minix/timers.h>
   5 #include <string.h>
   6
   7 #include "kernel/config.h"
   8 #include "kernel/const.h"
   9 #include "kernel/type.h"
  10 #include "kernel/proc.h"
  11
  12 /*===========================================================================*
  13  *                              sched_inherit                                *
  14  *===========================================================================*/
  15 int sched_inherit(endpoint_t scheduler_e,
  16         endpoint_t schedulee_e, endpoint_t parent_e, unsigned maxprio,
  17         endpoint_t *newscheduler_e)
  18 {
  19         int rv;
  20         message m;
  21
  22         assert(_ENDPOINT_P(scheduler_e) >= 0);
  23         assert(_ENDPOINT_P(schedulee_e) >= 0);
  24         assert(_ENDPOINT_P(parent_e) >= 0);
  25         assert(maxprio < NR_SCHED_QUEUES);
  26         assert(newscheduler_e);
  27
  28         memset(&m, 0, sizeof(m));
  29         m.SCHEDULING_ENDPOINT   = schedulee_e;
  30         m.SCHEDULING_PARENT     = parent_e;
  31         m.SCHEDULING_MAXPRIO    = (int) maxprio;
  32
  33         /* Send the request to the scheduler */
  34         if ((rv = _taskcall(scheduler_e, SCHEDULING_INHERIT, &m))) {
  35                 return rv;
  36         }
  37
  38         /* Store the process' scheduler. Note that this might not be the
  39          * scheduler we sent the SCHEDULING_INHERIT message to. That scheduler
  40          * might have forwarded the scheduling message on to another scheduler
  41          * before returning the message.
  42          */
  43         *newscheduler_e = m.SCHEDULING_SCHEDULER;
  44         return (OK);
  45 }
  46
  47 /*===========================================================================*
  48  *                              sched_start                                  *
  49  *===========================================================================*/
  50 int sched_start(endpoint_t scheduler_e,
  51                         endpoint_t schedulee_e,
  52                         endpoint_t parent_e,
  53                         int maxprio,
  54                         int quantum,
  55                         int cpu,
  56                         endpoint_t *newscheduler_e)
  57 {
  58         int rv;
  59         message m;
  60
  61         /* No scheduler given? We are done. */
  62         if(scheduler_e == NONE) {
  63                 return OK;
  64         }
  65
  66         assert(_ENDPOINT_P(schedulee_e) >= 0);
  67         assert(_ENDPOINT_P(parent_e) >= 0);
  68         assert(maxprio >= 0);
  69         assert(maxprio < NR_SCHED_QUEUES);
  70         assert(quantum > 0);
  71         assert(newscheduler_e);
  72
  73         /* The KERNEL must schedule this process. */
  74         if(scheduler_e == KERNEL) {
  75                 if ((rv = sys_schedctl(SCHEDCTL_FLAG_KERNEL,
  76                         schedulee_e, maxprio, quantum, cpu)) != OK) {
  77                         return rv;
  78                 }
  79                 *newscheduler_e = scheduler_e;
  80                 return OK;
  81         }
  82
  83         /* A user-space scheduler must schedule this process. */
  84         memset(&m, 0, sizeof(m));
  85         m.SCHEDULING_ENDPOINT   = schedulee_e;
  86         m.SCHEDULING_PARENT     = parent_e;
  87         m.SCHEDULING_MAXPRIO    = (int) maxprio;
  88         m.SCHEDULING_QUANTUM    = (int) quantum;
  89
  90         /* Send the request to the scheduler */
  91         if ((rv = _taskcall(scheduler_e, SCHEDULING_START, &m))) {
  92                 return rv;
  93         }
  94
  95         /* Store the process' scheduler. Note that this might not be the
  96          * scheduler we sent the SCHEDULING_START message to. That scheduler
  97          * might have forwarded the scheduling message on to another scheduler
  98          * before returning the message.
  99          */
 100         *newscheduler_e = m.SCHEDULING_SCHEDULER;
 101         return (OK);
 102 }