arch/um/os-Linux/time.c

   1 /*
   2  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <unistd.h>
   9 #include <time.h>
  10 #include <sys/time.h>
  11 #include <signal.h>
  12 #include <errno.h>
  13 #include "kern_util.h"
  14 #include "user.h"
  15 #include "process.h"
  16 #include "kern_constants.h"
  17 #include "os.h"
  18 #include "uml-config.h"
  19
  20 int set_interval(int is_virtual)
  21 {
  22         int usec = 1000000/hz();
  23         int timer_type = is_virtual ? ITIMER_VIRTUAL : ITIMER_REAL;
  24         struct itimerval interval = ((struct itimerval) { { 0, usec },
  25                                                           { 0, usec } });
  26
  27         if(setitimer(timer_type, &interval, NULL) == -1)
  28                 return -errno;
  29
  30         return 0;
  31 }
  32
  33 #ifdef UML_CONFIG_MODE_TT
  34 void enable_timer(void)
  35 {
  36         set_interval(1);
  37 }
  38 #endif
  39
  40 void disable_timer(void)
  41 {
  42         struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
  43         if((setitimer(ITIMER_VIRTUAL, &disable, NULL) < 0) ||
  44            (setitimer(ITIMER_REAL, &disable, NULL) < 0))
  45                 printk("disnable_timer - setitimer failed, errno = %d\n",
  46                        errno);
  47         /* If there are signals already queued, after unblocking ignore them */
  48         signal(SIGALRM, SIG_IGN);
  49         signal(SIGVTALRM, SIG_IGN);
  50 }
  51
  52 void switch_timers(int to_real)
  53 {
  54         struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
  55         struct itimerval enable = ((struct itimerval) { { 0, 1000000/hz() },
  56                                                         { 0, 1000000/hz() }});
  57         int old, new;
  58
  59         if(to_real){
  60                 old = ITIMER_VIRTUAL;
  61                 new = ITIMER_REAL;
  62         }
  63         else {
  64                 old = ITIMER_REAL;
  65                 new = ITIMER_VIRTUAL;
  66         }
  67
  68         if((setitimer(old, &disable, NULL) < 0) ||
  69            (setitimer(new, &enable, NULL)))
  70                 printk("switch_timers - setitimer failed, errno = %d\n",
  71                        errno);
  72 }
  73
  74 #ifdef UML_CONFIG_MODE_TT
  75 void uml_idle_timer(void)
  76 {
  77         if(signal(SIGVTALRM, SIG_IGN) == SIG_ERR)
  78                 panic("Couldn't unset SIGVTALRM handler");
  79
  80         set_handler(SIGALRM, (__sighandler_t) alarm_handler,
  81                     SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
  82         set_interval(0);
  83 }
  84 #endif
  85
  86 unsigned long long os_nsecs(void)
  87 {
  88         struct timeval tv;
  89
  90         gettimeofday(&tv, NULL);
  91         return((unsigned long long) tv.tv_sec * BILLION + tv.tv_usec * 1000);
  92 }
  93
  94 void idle_sleep(int secs)
  95 {
  96         struct timespec ts;
  97
  98         ts.tv_sec = secs;
  99         ts.tv_nsec = 0;
 100         nanosleep(&ts, NULL);
 101 }