C++ set_normalized_timespec函数代码示例

int do_settimeofday (struct timespec *tv)
{
	time_t wtm_sec, sec = tv->tv_sec;
	long wtm_nsec, nsec = tv->tv_nsec;

	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
		return -EINVAL;

	write_seqlock_irq(&xtime_lock);
	{
		wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
		wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);

		set_normalized_timespec(&xtime, sec, nsec);
		set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);

		time_adjust = 0;		/* stop active adjtime() */
		time_status |= STA_UNSYNC;
		time_maxerror = NTP_PHASE_LIMIT;
		time_esterror = NTP_PHASE_LIMIT;
		time_interpolator_reset();
	}
	write_sequnlock_irq(&xtime_lock);
	clock_was_set();
	return 0;
}

int do_settimeofday(struct timespec *tv)
{
	time_t wtm_sec, sec = tv->tv_sec;
	long wtm_nsec, nsec = tv->tv_nsec;

	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
		return -EINVAL;

	write_seqlock_irq(&xtime_lock);
	/*
	 * This is revolting. We need to set "xtime" correctly. However, the
	 * value in this location is the value at the most recent update of
	 * wall time.  Discover what correction gettimeofday() would have
	 * made, and then undo it!
	 */
	nsec -= get_timer_offset() * NSEC_PER_USEC;

	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);

	set_normalized_timespec(&xtime, sec, nsec);
	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);

	ntp_clear();
	write_sequnlock_irq(&xtime_lock);
	clock_was_set();

	return 0;
}

int do_settimeofday(struct timespec *tv)
{
	time_t wtm_sec, sec = tv->tv_sec;
	long wtm_nsec, nsec = tv->tv_nsec;

	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
		return -EINVAL;

	write_seqlock_irq(&xtime_lock);
	/* This is revolting. We need to set the xtime.tv_nsec
	 * correctly. However, the value in this location is
	 * is value at the last tick.
	 * Discover what correction gettimeofday
	 * would have done, and then undo it!
	 */
	nsec -= 1000 * mach_gettimeoffset();

	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);

	set_normalized_timespec(&xtime, sec, nsec);
	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);

	ntp_clear();
	write_sequnlock_irq(&xtime_lock);
	clock_was_set();
	return 0;
}

static int sbus_do_settimeofday(struct timespec *tv)
{
	time_t wtm_sec, sec = tv->tv_sec;
	long wtm_nsec, nsec = tv->tv_nsec;

	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
		return -EINVAL;

	/*
	 * This is revolting. We need to set "xtime" correctly. However, the
	 * value in this location is the value at the most recent update of
	 * wall time.  Discover what correction gettimeofday() would have
	 * made, and then undo it!
	 */
	nsec -= 1000 * (do_gettimeoffset() +
			(jiffies - wall_jiffies) * (USEC_PER_SEC / HZ));

	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);

	set_normalized_timespec(&xtime, sec, nsec);
	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);

	time_adjust = 0;		/* stop active adjtime() */
	time_status |= STA_UNSYNC;
	time_maxerror = NTP_PHASE_LIMIT;
	time_esterror = NTP_PHASE_LIMIT;
	return 0;
}

int do_settimeofday(struct timespec *tv)
{
	time_t wtm_sec, sec = tv->tv_sec;
	long wtm_nsec, nsec = tv->tv_nsec;

	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
		return -EINVAL;

	write_seqlock_irq(&xtime_lock);
	/*
	 * This is revolting. We need to set the xtime.tv_usec
	 * correctly. However, the value in this location is
	 * is value at the last tick.
	 * Discover what correction gettimeofday
	 * would have done, and then undo it!
	 */
	if (mach_gettimeoffset)
		nsec -= (mach_gettimeoffset() * 1000);

	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);

	set_normalized_timespec(&xtime, sec, nsec);
	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);

	time_adjust = 0;		/* stop active adjtime() */
	time_status |= STA_UNSYNC;
	time_maxerror = NTP_PHASE_LIMIT;
	time_esterror = NTP_PHASE_LIMIT;
	write_sequnlock_irq(&xtime_lock);
	clock_was_set();
	return 0;
}

int do_settimeofday(struct timespec *tv)
{
	time_t wtm_sec, new_sec = tv->tv_sec;
	long wtm_nsec, new_nsec = tv->tv_nsec;
	unsigned long flags;
	int tb_delta;

	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
		return -EINVAL;

	write_seqlock_irqsave(&xtime_lock, flags);
	/* Updating the RTC is not the job of this code. If the time is
	 * stepped under NTP, the RTC will be update after STA_UNSYNC
	 * is cleared. Tool like clock/hwclock either copy the RTC
	 * to the system time, in which case there is no point in writing
	 * to the RTC again, or write to the RTC but then they don't call
	 * settimeofday to perform this operation. Note also that
	 * we don't touch the decrementer since:
	 * a) it would lose timer interrupt synchronization on SMP
	 * (if it is working one day)
	 * b) it could make one jiffy spuriously shorter or longer
	 * which would introduce another source of uncertainty potentially
	 * harmful to relatively short timers.
	 */

	/* This works perfectly on SMP only if the tb are in sync but
	 * guarantees an error < 1 jiffy even if they are off by eons,
	 * still reasonable when gettimeofday resolution is 1 jiffy.
	 */
	tb_delta = tb_ticks_since(last_jiffy_stamp(smp_processor_id()));
	tb_delta += (jiffies - wall_jiffies) * tb_ticks_per_jiffy;

	new_nsec -= 1000 * mulhwu(tb_to_us, tb_delta);

	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - new_sec);
	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - new_nsec);

	set_normalized_timespec(&xtime, new_sec, new_nsec);
	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);

	/* In case of a large backwards jump in time with NTP, we want the
	 * clock to be updated as soon as the PLL is again in lock.
	 */
	last_rtc_update = new_sec - 658;

	time_adjust = 0;                /* stop active adjtime() */
	time_status |= STA_UNSYNC;
	time_maxerror = NTP_PHASE_LIMIT;
	time_esterror = NTP_PHASE_LIMIT;
	write_sequnlock_irqrestore(&xtime_lock, flags);
	clock_was_set();
	return 0;
}

void __init time_init(void)
{
	long long nsecs;

	timer_init();

	nsecs = os_nsecs();
	set_normalized_timespec(&wall_to_monotonic, -nsecs / NSEC_PER_SEC,
				-nsecs % NSEC_PER_SEC);
	set_normalized_timespec(&xtime, nsecs / NSEC_PER_SEC,
				nsecs % NSEC_PER_SEC);
	late_time_init = setup_itimer;
}

void __init time_init(void)
{
	time_t sec_o, sec_n = 0;

	/* The platform must provide a function to calibrate the processor
	 * speed for the CALIBRATE.
	 */

#ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT
	printk("Calibrating CPU frequency ");
	platform_calibrate_ccount();
	printk("%d.%02d MHz\n", (int)ccount_per_jiffy/(1000000/HZ),
			(int)(ccount_per_jiffy/(10000/HZ))%100);
#endif

	/* Set time from RTC (if provided) */

	if (platform_get_rtc_time(&sec_o) == 0)
		while (platform_get_rtc_time(&sec_n))
			if (sec_o != sec_n)
				break;

	xtime.tv_nsec = 0;
	last_rtc_update = xtime.tv_sec = sec_n;
	last_ccount_stamp = get_ccount();

	set_normalized_timespec(&wall_to_monotonic,
		-xtime.tv_sec, -xtime.tv_nsec);

	/* Initialize the linux timer interrupt. */

	setup_irq(LINUX_TIMER_INT, &timer_irqaction);
	set_linux_timer(get_ccount() + CCOUNT_PER_JIFFY);
}

void read_persistent_clock(struct timespec *ts)
{
	long long nsecs = os_nsecs();

	set_normalized_timespec(ts, nsecs / NSEC_PER_SEC,
				nsecs % NSEC_PER_SEC);
}

void __init time_init(void)
{
	if (board_time_init)
		board_time_init();

	clk_init();

	rtc_sh_get_time(&xtime);
	set_normalized_timespec(&wall_to_monotonic,
				-xtime.tv_sec, -xtime.tv_nsec);

#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
	local_timer_setup(smp_processor_id());
#endif

	/*
	 * Make sure all compiled-in early timers register themselves.
	 *
	 * Run probe() for two "earlytimer" devices, these will be the
	 * clockevents and clocksource devices respectively. In the event
	 * that only a clockevents device is available, we -ENODEV on the
	 * clocksource and the jiffies clocksource is used transparently
	 * instead. No error handling is necessary here.
	 */
	early_platform_driver_register_all("earlytimer");
	early_platform_driver_probe("earlytimer", 2, 0);
}

/*
 * Initialize the TOD clock and the CPU timer of
 * the boot cpu.
 */
void __init time_init(void)
{
	u64 init_timer_cc;

	init_timer_cc = reset_tod_clock();
	jiffies_timer_cc = init_timer_cc - jiffies_64 * CLK_TICKS_PER_JIFFY;

	/* set xtime */
	tod_to_timeval(init_timer_cc - TOD_UNIX_EPOCH, &xtime);
        set_normalized_timespec(&wall_to_monotonic,
                                -xtime.tv_sec, -xtime.tv_nsec);

	/* request the clock comparator external interrupt */
	if (register_early_external_interrupt(0x1004,
					      clock_comparator_interrupt,
					      &ext_int_info_cc) != 0)
                panic("Couldn't request external interrupt 0x1004");

	if (clocksource_register(&clocksource_tod) != 0)
		panic("Could not register TOD clock source");

	/* request the timing alert external interrupt */
	if (register_early_external_interrupt(0x1406,
					      timing_alert_interrupt,
					      &ext_int_etr_cc) != 0)
		panic("Couldn't request external interrupt 0x1406");

	/* Enable TOD clock interrupts on the boot cpu. */
	init_cpu_timer();

#ifdef CONFIG_VIRT_TIMER
	vtime_init();
#endif
}

/**
 * Mac OS X doesn't have clock_gettime function,
 * we'll use gettimeofday instead.
 * In production you should probably use mach_monotonous_time or something
 */
int clock_gettime(int UNUSED(_), struct timespec *ts) { 
    struct timeval tv; 

    gettimeofday(&tv, NULL); 
    set_normalized_timespec(ts, tv.tv_sec, tv.tv_usec * 1000);
    return 0; 
} 

void pvclock_read_wallclock(struct pvclock_wall_clock *wall_clock,
			    struct pvclock_vcpu_time_info *vcpu_time,
			    struct timespec *ts)
{
	u32 version;
	u64 delta;
	struct timespec now;

	/* get wallclock at system boot */
	do {
		version = wall_clock->version;
		rmb();		/* fetch version before time */
		now.tv_sec  = wall_clock->sec;
		now.tv_nsec = wall_clock->nsec;
		rmb();		/* fetch time before checking version */
	} while ((wall_clock->version & 1) || (version != wall_clock->version));

	delta = pvclock_clocksource_read(vcpu_time);	/* time since system boot */
	delta += now.tv_sec * (u64)NSEC_PER_SEC + now.tv_nsec;

	now.tv_nsec = do_div(delta, NSEC_PER_SEC);
	now.tv_sec = delta;

	set_normalized_timespec(ts, now.tv_sec, now.tv_nsec);
}

void __init time_init(void)
{
	if (board_time_init)
		board_time_init();

	clk_init();

	rtc_sh_get_time(&xtime);
	set_normalized_timespec(&wall_to_monotonic,
				-xtime.tv_sec, -xtime.tv_nsec);

#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
	local_timer_setup(smp_processor_id());
#endif

	/*
	 * Find the timer to use as the system timer, it will be
	 * initialized for us.
	 */
	sys_timer = get_sys_timer();
	printk(KERN_INFO "Using %s for system timer\n", sys_timer->name);


	if (sys_timer->ops->read)
		clocksource_sh.read = sys_timer->ops->read;

	init_sh_clocksource();

	if (sh_hpt_frequency)
		printk("Using %lu.%03lu MHz high precision timer.\n",
		       ((sh_hpt_frequency + 500) / 1000) / 1000,
		       ((sh_hpt_frequency + 500) / 1000) % 1000);

}

void __init time_init(void)
{
	int ret;

	/*
	 * Make sure we don't get any COMPARE interrupts before we can
	 * handle them.
	 */
	sysreg_write(COMPARE, 0);

	xtime.tv_sec = rtc_get_time();
	xtime.tv_nsec = 0;

	set_normalized_timespec(&wall_to_monotonic,
				-xtime.tv_sec, -xtime.tv_nsec);

	ret = avr32_hpt_init();
	if (ret) {
		pr_debug("timer: failed setup: %d\n", ret);
		return;
	}

	ret = clocksource_register(&clocksource_avr32);
	if (ret)
		pr_debug("timer: could not register clocksource: %d\n", ret);

	ret = avr32_hpt_start();
	if (ret) {
		pr_debug("timer: failed starting: %d\n", ret);
		return;
	}
}