uclibc-ng/libc/sysdeps/linux/common/clock_getres.c

/*
 * clock_getres() for uClibc
 *
 * Copyright (C) 2005 by Peter Kjellerstedt <pkj@axis.com>
 * Copyright (C) 2000-2006 Erik Andersen <andersen@uclibc.org>
 *
 * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
 */

#include <sys/syscall.h>
#include <time.h>

#if defined(__UCLIBC_USE_TIME64__) && defined(__NR_clock_getres_time64)
#include "internal/time64_helpers.h"

int clock_getres(clockid_t clock_id, struct timespec *res)
{
	struct __ts64_struct __ts64;
	int __ret = INLINE_SYSCALL(clock_getres_time64, 2, clock_id, &__ts64);
	if (__ret == 0 && res) {
		res->tv_sec = __ts64.tv_sec;
		res->tv_nsec = __ts64.tv_nsec;
	};

	return __ret;
}
#elif defined(__NR_clock_getres)
_syscall2(int, clock_getres, clockid_t, clock_id, struct timespec*, res)
#else
# include <unistd.h>

int clock_getres(clockid_t clock_id, struct timespec* res)
{
	int retval = -1;

	switch (clock_id) {
		case CLOCK_REALTIME:
			if (res) {
				long clk_tck;

				if ((clk_tck = sysconf(_SC_CLK_TCK)) < 0)
					clk_tck = 100;
				res->tv_sec = 0;
				res->tv_nsec = 1000000000 / clk_tck;
			}
			retval = 0;
			break;

		default:
			errno = EINVAL;
			break;
	}

	return retval;
}
#endif
libc_hidden_def(clock_getres)