#ifndef _SYS_TIME_H
#define _SYS_TIME_H
#ifdef __cplusplus
extern "C" {
#endif

#include <features.h>

#include <sys/select.h>

int gettimeofday(struct timeval* __restrict, void* __restrict);

#if defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || defined(_BSD_SOURCE)

#define ITIMER_REAL 0
#define ITIMER_VIRTUAL 1
#define ITIMER_PROF 2

struct itimerval {
  struct timeval it_interval;
  struct timeval it_value;
};

int getitimer(int, struct itimerval*);
int setitimer(int,
              const struct itimerval* __restrict,
              struct itimerval* __restrict);
int utimes(const char*, const struct timeval[2]);

#endif

#if defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
struct timezone {
  int tz_minuteswest;
  int tz_dsttime;
};
int futimes(int, const struct timeval[2]);
int futimesat(int, const char*, const struct timeval[2]);
int lutimes(const char*, const struct timeval[2]);
int settimeofday(const struct timeval*, const struct timezone*);
int adjtime(const struct timeval*, struct timeval*);
#define timerisset(t) ((t)->tv_sec || (t)->tv_usec)
#define timerclear(t) ((t)->tv_sec = (t)->tv_usec = 0)
#define timercmp(s, t, op)                                  \
  ((s)->tv_sec == (t)->tv_sec ? (s)->tv_usec op(t)->tv_usec \
                              : (s)->tv_sec op(t)->tv_sec)
#define timeradd(s, t, a)                                           \
  (void)((a)->tv_sec = (s)->tv_sec + (t)->tv_sec,                   \
         ((a)->tv_usec = (s)->tv_usec + (t)->tv_usec) >= 1000000 && \
             ((a)->tv_usec -= 1000000, (a)->tv_sec++))
#define timersub(s, t, a)                                    \
  (void)((a)->tv_sec = (s)->tv_sec - (t)->tv_sec,            \
         ((a)->tv_usec = (s)->tv_usec - (t)->tv_usec) < 0 && \
             ((a)->tv_usec += 1000000, (a)->tv_sec--))
#endif

#if defined(_GNU_SOURCE)
#define TIMEVAL_TO_TIMESPEC(tv, ts) \
  ((ts)->tv_sec = (tv)->tv_sec, (ts)->tv_nsec = (tv)->tv_usec * 1000, (void)0)
#define TIMESPEC_TO_TIMEVAL(tv, ts) \
  ((tv)->tv_sec = (ts)->tv_sec, (tv)->tv_usec = (ts)->tv_nsec / 1000, (void)0)
#endif

#ifdef __cplusplus
}
#endif
#endif