minix/lib/libc/sys/priority.c

   1 /*
   2 priority.c
   3 */
   4
   5 #include <sys/cdefs.h>
   6 #include "namespace.h"
   7 #include <errno.h>
   8 #include <sys/types.h>
   9 #include <sys/resource.h>
  10 #include <lib.h>
  11 #include <unistd.h>
  12 #include <string.h>
  13 #include <stddef.h>
  14
  15
  16 int getpriority(int which, id_t who)
  17 {
  18         int v;
  19         message m;
  20
  21         memset(&m, 0, sizeof(m));
  22         m.m_lc_pm_priority.which = which;
  23         m.m_lc_pm_priority.who = who;
  24
  25         /* GETPRIORITY returns negative for error.
  26          * Otherwise, it returns the priority plus the minimum
  27          * priority, to distiginuish from error. We have to
  28          * correct for this. (The user program has to check errno
  29          * to see if something really went wrong.)
  30          */
  31
  32         if((v = _syscall(PM_PROC_NR, PM_GETPRIORITY, &m)) < 0) {
  33                 return v;
  34         }
  35
  36         return v + PRIO_MIN;
  37 }
  38
  39 int setpriority(int which, id_t who, int prio)
  40 {
  41         message m;
  42
  43         memset(&m, 0, sizeof(m));
  44         m.m_lc_pm_priority.which = which;
  45         m.m_lc_pm_priority.who = who;
  46         m.m_lc_pm_priority.prio = prio;
  47
  48         return _syscall(PM_PROC_NR, PM_SETPRIORITY, &m);
  49 }
  50