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incubator-nuttx/include/sys/time.h

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/****************************************************************************
* include/sys/time.h
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
#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]);
int lutimes(FAR const char *path, const struct timeval times[2]);
/****************************************************************************
* Name: futimes
*
* Description:
* futimes() update the timestamps of a file with microsecond precision.
* With futimes() 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, futimes() 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: 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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