incubator-nuttx/include/sys/time.h

240 lines
7.8 KiB
C

/****************************************************************************
* include/sys/time.h
*
* Copyright (C) 2009, 2015-2016 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>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* 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))
/****************************************************************************
* Public Type Definitions
****************************************************************************/
/* struct timeval represents time as seconds plus microseconds */
struct timeval
{
time_t tv_sec; /* Seconds */
long tv_usec; /* Microseconds */
};
/* 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
#undef EXTERN
#if defined(__cplusplus)
}
#endif
#endif /* __INCLUDE_SYS_TIME_H */