incubator-nuttx/include/time.h

264 lines
8.6 KiB
C

/********************************************************************************
* include/time.h
*
* Copyright (C) 2007-2011, 2013-2015, 2017 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
********************************************************************************/
#ifndef __INCLUDE_TIME_H
#define __INCLUDE_TIME_H
/********************************************************************************
* Included Files
********************************************************************************/
#include <nuttx/config.h>
#include <nuttx/compiler.h>
#include <sys/types.h>
#include <stdint.h>
/********************************************************************************
* Pre-processor Definitions
********************************************************************************/
/* Clock tick of the system (frequency Hz).
*
* NOTE: This symbolic name CLK_TCK has been removed from the standard. It is
* replaced with CLOCKS_PER_SEC. Both are defined here.
*
* The default value is 100Hz, but this default setting can be overridden by
* defining the clock interval in microseconds as CONFIG_USEC_PER_TICK in the
* board configuration file.
*/
#ifdef CONFIG_USEC_PER_TICK
# define CLK_TCK (1000000/CONFIG_USEC_PER_TICK)
# define CLOCKS_PER_SEC (1000000/CONFIG_USEC_PER_TICK)
#else
# define CLK_TCK (100)
# define CLOCKS_PER_SEC (100)
#endif
/* CLOCK_REALTIME refers to the standard time source. For most
* implementations, the standard time source is the system timer interrupt.
* However, if the platform supports an RTC, then the standard time source
* will be the RTC for the clock_gettime() and clock_settime() interfaces
* (the system timer is still the time source for all of the interfaces).
*
* CLOCK_REALTIME represents the machine's best-guess as to the current
* wall-clock, time-of-day time. This means that CLOCK_REALTIME can jump
* forward and backward as the system time-of-day clock is changed.
*/
#define CLOCK_REALTIME 0
/* Clock that cannot be set and represents monotonic time since some
* unspecified starting point. It is not affected by changes in the
* system time-of-day clock.
*/
#ifdef CONFIG_CLOCK_MONOTONIC
# define CLOCK_MONOTONIC 1
#endif
/* This is a flag that may be passed to the timer_settime() and
* clock_nanosleep() functions.
*/
#define TIMER_ABSTIME 1
/* Time base values for timespec_get. */
#define TIME_UTC 1
#ifndef CONFIG_LIBC_LOCALTIME
/* Local time is the same as gmtime in this implementation */
# define localtime(c) gmtime(c)
# define localtime_r(c,r) gmtime_r(c,r)
#endif
/********************************************************************************
* Public Types
********************************************************************************/
/* Scalar types */
typedef uint32_t time_t; /* Holds time in seconds */
typedef uint8_t clockid_t; /* Identifies one time base source */
typedef FAR void *timer_t; /* Represents one POSIX timer */
/* struct timespec is the standard representation of time as seconds and
* nanoseconds.
*/
struct timespec
{
time_t tv_sec; /* Seconds */
long tv_nsec; /* Nanoseconds */
};
/* struct tm is the standard representation for "broken out" time.
*
* REVISIT: This structure could be packed better using uint8_t's and
* uint16_t's. The standard definition does, however, call out type int for
* all of the members. NOTE: Any changes to this structure must be also be
* reflected in struct rtc_time defined in include/nuttx/timers/rtc.h; these
* two structures must be cast compatible.
*/
struct tm
{
int tm_sec; /* Seconds (0-61, allows for leap seconds) */
int tm_min; /* Minutes (0-59) */
int tm_hour; /* Hours (0-23) */
int tm_mday; /* Day of the month (1-31) */
int tm_mon; /* Month (0-11) */
int tm_year; /* Years since 1900 */
int tm_wday; /* Day of the week (0-6) */
int tm_yday; /* Day of the year (0-365) */
int tm_isdst; /* Non-0 if daylight savings time is in effect */
};
/* Struct itimerspec is used to define settings for an interval timer */
struct itimerspec
{
struct timespec it_value; /* First time */
struct timespec it_interval; /* and thereafter */
};
/* forward reference (defined in signal.h) */
struct sigevent;
/********************************************************************************
* Public Data
********************************************************************************/
#undef EXTERN
#if defined(__cplusplus)
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
#ifdef CONFIG_LIBC_LOCALTIME
/* daylight - Daylight savings time flag */
/* EXTERN int daylight; not supported */
/* timezone - Difference from UTC and local standard time */
/* EXTERN long int timezone; not supported */
/* tzname[] - Timezone strings
* Setup by tzset()
*/
EXTERN FAR char *tzname[2];
#endif
/********************************************************************************
* Public Function Prototypes
********************************************************************************/
clock_t clock(void);
int clock_settime(clockid_t clockid, FAR const struct timespec *tp);
int clock_gettime(clockid_t clockid, FAR struct timespec *tp);
int clock_getres(clockid_t clockid, FAR struct timespec *res);
#ifdef CONFIG_HAVE_INLINE
static inline int timespec_get(FAR struct timespec *t, int b)
{
return b == TIME_UTC ? (clock_gettime(CLOCK_REALTIME, t), b) : 0;
}
#else
#define timespec_get(t, b) \
((b) == TIME_UTC ? (clock_gettime(CLOCK_REALTIME, (t)), (b)) : 0)
#endif
time_t mktime(FAR struct tm *tp);
FAR struct tm *gmtime(FAR const time_t *timep);
FAR struct tm *gmtime_r(FAR const time_t *timep, FAR struct tm *result);
#ifdef CONFIG_LIBC_LOCALTIME
FAR struct tm *localtime(FAR const time_t *timep);
FAR struct tm *localtime_r(FAR const time_t *timep, FAR struct tm *result);
#endif
size_t strftime(FAR char *s, size_t max, FAR const char *format,
FAR const struct tm *tm);
FAR char *asctime(FAR const struct tm *tp);
FAR char *asctime_r(FAR const struct tm *tp, FAR char *buf);
FAR char *ctime(FAR const time_t *timep);
FAR char *ctime_r(FAR const time_t *timep, FAR char *buf);
time_t time(FAR time_t *timep);
#ifdef CONFIG_HAVE_DOUBLE
double difftime(time_t time1, time_t time0);
#else
float difftime(time_t time1, time_t time0);
#endif
int timer_create(clockid_t clockid, FAR struct sigevent *evp,
FAR timer_t *timerid);
int timer_delete(timer_t timerid);
int timer_settime(timer_t timerid, int flags,
FAR const struct itimerspec *value,
FAR struct itimerspec *ovalue);
int timer_gettime(timer_t timerid, FAR struct itimerspec *value);
int timer_getoverrun(timer_t timerid);
int clock_nanosleep(clockid_t clockid, int flags,
FAR const struct timespec *rqtp,
FAR struct timespec *rmtp);
int nanosleep(FAR const struct timespec *rqtp, FAR struct timespec *rmtp);
#ifdef CONFIG_LIBC_LOCALTIME
void tzset(void);
#endif
#undef EXTERN
#if defined(__cplusplus)
}
#endif
#endif /* __INCLUDE_TIME_H */