arch/um/os-Linux/time.c

   1 /*
   2  * Copyright (C) 2000 - 2007 Jeff Dike (jdike{addtoit,linux.intel}.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include <stddef.h>
   7 #include <errno.h>
   8 #include <signal.h>
   9 #include <time.h>
  10 #include <sys/time.h>
  11 #include "kern_util.h"
  12 #include "kern_constants.h"
  13 #include "os.h"
  14 #include "user.h"
  15
  16 int set_interval(int is_virtual)
  17 {
  18         int usec = 1000000/hz();
  19         int timer_type = is_virtual ? ITIMER_VIRTUAL : ITIMER_REAL;
  20         struct itimerval interval = ((struct itimerval) { { 0, usec },
  21                                                           { 0, usec } });
  22
  23         if (setitimer(timer_type, &interval, NULL) == -1)
  24                 return -errno;
  25
  26         return 0;
  27 }
  28
  29 void disable_timer(void)
  30 {
  31         struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
  32
  33         if ((setitimer(ITIMER_VIRTUAL, &disable, NULL) < 0) ||
  34             (setitimer(ITIMER_REAL, &disable, NULL) < 0))
  35                 printk(UM_KERN_ERR "disable_timer - setitimer failed, "
  36                        "errno = %d\n", errno);
  37
  38         /* If there are signals already queued, after unblocking ignore them */
  39         signal(SIGALRM, SIG_IGN);
  40         signal(SIGVTALRM, SIG_IGN);
  41 }
  42
  43 void switch_timers(int to_real)
  44 {
  45         struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
  46         struct itimerval enable = ((struct itimerval) { { 0, 1000000/hz() },
  47                                                         { 0, 1000000/hz() }});
  48         int old, new;
  49
  50         if (to_real) {
  51                 old = ITIMER_VIRTUAL;
  52                 new = ITIMER_REAL;
  53         }
  54         else {
  55                 old = ITIMER_REAL;
  56                 new = ITIMER_VIRTUAL;
  57         }
  58
  59         if ((setitimer(old, &disable, NULL) < 0) ||
  60             (setitimer(new, &enable, NULL)))
  61                 printk(UM_KERN_ERR "switch_timers - setitimer failed, "
  62                        "errno = %d\n", errno);
  63 }
  64
  65 unsigned long long os_nsecs(void)
  66 {
  67         struct timeval tv;
  68
  69         gettimeofday(&tv, NULL);
  70         return (unsigned long long) tv.tv_sec * BILLION + tv.tv_usec * 1000;
  71 }
  72
  73 void idle_sleep(int secs)
  74 {
  75         struct timespec ts;
  76
  77         ts.tv_sec = secs;
  78         ts.tv_nsec = 0;
  79         nanosleep(&ts, NULL);
  80 }