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 "user_util.h"
  14 #include "kern_util.h"
  15 #include "user.h"
  16 #include "process.h"
  17 #include "kern_constants.h"
  18 #include "os.h"
  19 #include "uml-config.h"
  20
  21 int set_interval(int is_virtual)
  22 {
  23         int usec = 1000000/hz();
  24         int timer_type = is_virtual ? ITIMER_VIRTUAL : ITIMER_REAL;
  25         struct itimerval interval = ((struct itimerval) { { 0, usec },
  26                                                           { 0, usec } });
  27
  28         if(setitimer(timer_type, &interval, NULL) == -1)
  29                 return -errno;
  30
  31         return 0;
  32 }
  33
  34 #ifdef UML_CONFIG_MODE_TT
  35 void enable_timer(void)
  36 {
  37         set_interval(1);
  38 }
  39 #endif
  40
  41 void disable_timer(void)
  42 {
  43         struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
  44         if((setitimer(ITIMER_VIRTUAL, &disable, NULL) < 0) ||
  45            (setitimer(ITIMER_REAL, &disable, NULL) < 0))
  46                 printk("disnable_timer - setitimer failed, errno = %d\n",
  47                        errno);
  48         /* If there are signals already queued, after unblocking ignore them */
  49         signal(SIGALRM, SIG_IGN);
  50         signal(SIGVTALRM, SIG_IGN);
  51 }
  52
  53 void switch_timers(int to_real)
  54 {
  55         struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
  56         struct itimerval enable = ((struct itimerval) { { 0, 1000000/hz() },
  57                                                         { 0, 1000000/hz() }});
  58         int old, new;
  59
  60         if(to_real){
  61                 old = ITIMER_VIRTUAL;
  62                 new = ITIMER_REAL;
  63         }
  64         else {
  65                 old = ITIMER_REAL;
  66                 new = ITIMER_VIRTUAL;
  67         }
  68
  69         if((setitimer(old, &disable, NULL) < 0) ||
  70            (setitimer(new, &enable, NULL)))
  71                 printk("switch_timers - setitimer failed, errno = %d\n",
  72                        errno);
  73 }
  74
  75 #ifdef UML_CONFIG_MODE_TT
  76 void uml_idle_timer(void)
  77 {
  78         if(signal(SIGVTALRM, SIG_IGN) == SIG_ERR)
  79                 panic("Couldn't unset SIGVTALRM handler");
  80
  81         set_handler(SIGALRM, (__sighandler_t) alarm_handler,
  82                     SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
  83         set_interval(0);
  84 }
  85 #endif
  86
  87 unsigned long long os_nsecs(void)
  88 {
  89         struct timeval tv;
  90
  91         gettimeofday(&tv, NULL);
  92         return((unsigned long long) tv.tv_sec * BILLION + tv.tv_usec * 1000);
  93 }
  94
  95 void idle_sleep(int secs)
  96 {
  97         struct timespec ts;
  98
  99         ts.tv_sec = secs;
 100         ts.tv_nsec = 0;
 101         nanosleep(&ts, NULL);
 102 }