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incubator-nuttx/include/sys/time.h

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/****************************************************************************
* include/sys/time.h
*
* Copyright (C) 2009, 2015-2016, 2019 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_SYS_TIME_H
#define __INCLUDE_SYS_TIME_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <time.h>
#include <sys/select.h>
#include <sys/types.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define ITIMER_REAL 0 /* Timers run in real time. */
#define ITIMER_VIRTUAL 1 /* Timers run only when the process is executing. */
#define ITIMER_PROF 2 /* Timers run when the process is executing and when
* the system is executing on behalf of the process.
*/
/* The following are non-standard interfaces in the sense that they are not
* in POSIX.1-2001 nor are they specified at OpenGroup.org. These interfaces
* are present on most BSD derivatives, however, including Linux.
*/
/* void timeradd(FAR struct timeval *a, FAR struct timeval *b,
* FAR struct timeval *res);
*/
#define timeradd(tvp, uvp, vvp) \
do \
{ \
(vvp)->tv_sec = (tvp)->tv_sec + (uvp)->tv_sec; \
(vvp)->tv_usec = (tvp)->tv_usec + (uvp)->tv_usec; \
if ((vvp)->tv_usec >= 1000000) \
{ \
(vvp)->tv_sec++; \
(vvp)->tv_usec -= 1000000; \
} \
} \
while (0)
/* void timersub(FAR struct timeval *a, FAR struct timeval *b,
* FAR struct timeval *res);
*/
#define timersub(tvp, uvp, vvp) \
do \
{ \
(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec; \
(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec; \
if ((vvp)->tv_usec < 0) \
{ \
(vvp)->tv_sec--; \
(vvp)->tv_usec += 1000000; \
} \
} \
while (0)
/* void timerclear(FAR struct timeval *tvp); */
#define timerclear(tvp) \
do \
{ \
(tvp)->tv_sec = 0; \
(tvp)->tv_usec = 0; \
} \
while (0)
/* int timerisset(FAR struct timeval *tvp); */
#define timerisset(tvp) \
((tvp)->tv_sec != 0 || (tvp)->tv_usec != 0)
/* int timercmp(FAR struct timeval *a, FAR struct timeval *b, CMP); */
#define timercmp(tvp, uvp, cmp) \
(((tvp)->tv_sec == (uvp)->tv_sec) ? \
((tvp)->tv_usec cmp (uvp)->tv_usec) : \
((tvp)->tv_sec cmp (uvp)->tv_sec))
/* Macros for converting between `struct timeval' and `struct timespec'. */
#define TIMEVAL_TO_TIMESPEC(tv, ts) \
do \
{ \
(ts)->tv_sec = (tv)->tv_sec; \
(ts)->tv_nsec = (tv)->tv_usec * 1000; \
} \
while (0)
#define TIMESPEC_TO_TIMEVAL(tv, ts) \
do \
{ \
(tv)->tv_sec = (ts)->tv_sec; \
(tv)->tv_usec = (ts)->tv_nsec / 1000; \
} \
while (0)
/****************************************************************************
* Public Type Definitions
****************************************************************************/
typedef clock_t hrtime_t;
/* struct timeval represents time as seconds plus microseconds */
struct timeval
{
time_t tv_sec; /* Seconds */
long tv_usec; /* Microseconds */
};
/* Type of the second argument to `getitimer' and
* the second and third arguments `setitimer'.
*/
struct itimerval
{
struct timeval it_interval; /* Interval for periodic timer */
struct timeval it_value; /* Time until next expiration */
};
/* The use of the struct timezone is obsolete; the tz argument should
* normally be specified as NULL (and is ignored in any event).
*/
struct timezone
{
int tz_minuteswest; /* Minutes west of Greenwich */
int tz_dsttime; /* Type of DST correction */
};
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#undef EXTERN
#if defined(__cplusplus)
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* Name: gettimeofday
*
* Description:
* Get the current time
*
* Conforming to SVr4, 4.3BSD. POSIX.1-2001 describes gettimeofday().
* POSIX.1-2008 marks gettimeofday() as obsolete, recommending the use of
* clock_gettime(2) instead.
*
* NuttX implements gettimeofday() as a thin layer around clock_gettime();
*
* Input Parameters:
* tv - The location to return the current time
* tz - Ignored
*
* Returned Value:
* Zero (OK) on success; -1 is returned on failure with the errno variable
* set appropriately.
*
****************************************************************************/
int gettimeofday(FAR struct timeval *tv, FAR struct timezone *tz);
/****************************************************************************
* Name: settimeofday
*
* Description:
* Set the current time
*
* Conforming to SVr4, 4.3BSD. POSIX.1-2001 describes gettimeofday() but
* not settimeofday().
*
* NuttX implements settimeofday() as a thin layer around clock_settime();
*
* Input Parameters:
* tv - The net to time to be set
* tz - Ignored
*
* Returned Value:
* Zero (OK) on success; -1 is returned on failure with the errno variable
* set appropriately.
*
****************************************************************************/
int settimeofday(FAR const struct timeval *tv, FAR struct timezone *tz);
/****************************************************************************
* Name: adjtime
*
* Description:
* The adjtime() function gradually adjusts the system clock (as returned
* by gettimeofday(2)). The amount of time by which the clock is to be
* adjusted is specified in the structure pointed to by delta.
*
* This structure has the following form:
*
* struct timeval
* {
* time_t tv_sec; (seconds)
* suseconds_t tv_usec; (microseconds)
* };
*
* If the adjustment in delta is positive, then the system clock is
* speeded up by some small percentage (i.e., by adding a small amount of
* time to the clock value in each second) until the adjustment has been
* completed. If the adjustment in delta is negative, then the clock is
* slowed down in a similar fashion.
*
* If a clock adjustment from an earlier adjtime() call is already in
* progress at the time of a later adjtime() call, and delta is not NULL
* for the later call, then the earlier adjustment is stopped, but any
* already completed part of that adjustment is not undone.
*
* If olddelta is not NULL, then the buffer that it points to is used to
* return the amount of time remaining from any previous adjustment that
* has not yet been completed.
*
* NOTE: This is not a POSIX interface but derives from 4.3BSD, System V.
* It is also supported for Linux compatibility.
*
****************************************************************************/
#ifdef CONFIG_CLOCK_TIMEKEEPING
int adjtime(FAR const struct timeval *delta, FAR struct timeval *olddelta);
#endif
/****************************************************************************
* Name: getitimer
*
* Description:
* The getitimer() function will store the amount of time until the
* specified timer, which, expires and the reload value of the timer
* into the space pointed to by the value argument. The it_value member
* of this structure will contain the amount of time before the timer
* expires, or zero if the timer is disarmed. This value is returned as
* the interval until timer expiration. The it_interval member of value
* will contain the reload value last set by setitime().
*
* Input Parameters:
* which - The predefined timer id
* value - The current timer value
*
* Returned Value:
* If the getitimer() succeeds, a value of 0 (OK) will be returned.
* If an error occurs, the value -1 (ERROR) will be returned, and errno
* set to indicate the error.
*
* EINVAL - The which argument does not correspond to an predefined ID.
*
* Assumptions/Limitations:
* Due to the asynchronous operation of this function, the time reported
* by this function could be significantly more than that actual time
* remaining on the timer at any time.
*
****************************************************************************/
int getitimer(int which, FAR struct itimerval *value);
/****************************************************************************
* Name: setitimer
*
* Description:
* The setitimer() function sets the time until the next expiration of
* the timer specified by which from the it_value member of the value
* argument and arm the timer if the it_value member of value is non-zero.
* If the specified timer was already armed when setitimer() is
* called, this call will reset the time until next expiration to the
* value specified. If the it_value member of value is zero, the timer
* will be disarmed. The effect of disarming or resetting a timer with
* pending expiration notifications is unspecified.
*
* The reload value of the timer will be set to the value specified by the
* it_interval member of value. When a timer is armed with a non-zero
* it_interval, a periodic (or repetitive) timer is specified.
*
* Time values that are between two consecutive non-negative integer
* multiples of the resolution of the specified timer will be rounded up
* to the larger multiple of the resolution. Quantization error will not
* cause the timer to expire earlier than the rounded time value.
*
* If the argument ovalue is not NULL, the setitimer() function will
* store, in the location referenced by ovalue, a value representing the
* previous amount of time before the timer would have expired, or zero if
* the timer was disarmed, together with the previous timer reload value.
* Timers will not expire before their scheduled time.
*
* Input Parameters:
* which - The predefined timer id
* value - Specifies the timer value to set
* ovalue - A location in which to return the time remaining from the
* previous timer setting.
*
* Returned Value:
* If the setitimer() succeeds, a value of 0 (OK) will be returned.
* If an error occurs, the value -1 (ERROR) will be returned, and errno set
* to indicate the error.
*
* EINVAL - The which argument does not correspond to an predefined ID.
* EINVAL - A value structure specified a microsecond value less than zero
* or greater than or equal to 1000 million, and the it_value member of
* that structure did not specify zero seconds and nanoseconds.
*
* Assumptions:
*
****************************************************************************/
int setitimer(int which, FAR const struct itimerval *value,
FAR struct itimerval *ovalue);
/****************************************************************************
* Name: utimes
*
* Description:
* The utimes() function shall set the access and modification times of the
* file pointed to by the path argument to the value of the times argument.
* utimes() function allows time specifications accurate to the microsecond.
* For utimes(), the times argument is an array of timeval structures. The
* first array member represents the date and time of last access, and the
* second member represents the date and time of last modification. The times
* in the timeval structure are measured in seconds and microseconds since
* the Epoch, although rounding toward the nearest second may occur.
* If the times argument is a null pointer, the access and modification times
* of the file shall be set to the current time. The effective user ID of the
* process shall match the owner of the file, has write access to the file or
* appropriate privileges to use this call in this manner. Upon completion,
* utimes() shall mark the time of the last file status change, st_ctime, for
* update.
*
* Input Parameters:
* path - Specifies the file to be modified
* times - Specifies the time value to set
*
* Returned Value:
* Upon successful completion, 0 shall be returned. Otherwise, -1 shall be
* returned and errno shall be set to indicate the error, and the file
* times shall not be affected.
*
****************************************************************************/
int utimes(FAR const char *path, const struct timeval times[2]);
/****************************************************************************
* Name: futimes
*
* Description:
* futimens() update the timestamps of a file with nanosecond precision.
* This contrasts with the historical utime(2) and utimes(2), which permit
* only second and microsecond precision, respectively, when setting file
* timestamps. With futimens() the file whose timestamps are to be updated
* is specified via an open file descriptor, fd.
*
* Input Parameters:
* fd - Specifies the fd to be modified
* times - Specifies the time value to set
*
* Returned Value:
* On success, futimens() return 0.
* On error, -1 is returned and errno is set to indicate the error.
*
****************************************************************************/
int futimes(int fd, const struct timeval tv[2]);
/****************************************************************************
* Name: futimes
*
* Description:
* futimens() update the timestamps of a file with nanosecond precision.
* This contrasts with the historical utime(2) and utimes(2), which permit
* only second and microsecond precision, respectively, when setting file
* timestamps.
*
* Input Parameters:
* fd - Specifies the fd to be modified
* times - Specifies the time value to set
*
* Returned Value:
* On success, futimens() return 0.
* On error, -1 is returned and errno is set to indicate the error.
*
****************************************************************************/
int futimens(int fd, const struct timespec times[2]);
/****************************************************************************
* Name: gethrtime
*
* Description:
* Get the current time
*
* Returned Value:
* The current value of the system time in ns
*
****************************************************************************/
hrtime_t gethrtime(void);
#undef EXTERN
#if defined(__cplusplus)
}
#endif
#endif /* __INCLUDE_SYS_TIME_H */
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