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/*
* Copyright (C) Igor Sysoev
* Copyright (C) NGINX, Inc.
*/
#ifndef _NXT_UNIX_TIME_H_INCLUDED_
#define _NXT_UNIX_TIME_H_INCLUDED_
typedef uint64_t nxt_nsec_t;
typedef int64_t nxt_nsec_int_t;
#define NXT_INFINITE_NSEC ((nxt_nsec_t) -1)
typedef struct {
nxt_time_t sec;
nxt_uint_t nsec;
} nxt_realtime_t;
/*
* nxt_monotonic_time_t includes nxt_realtime_t to eliminate
* surplus gettimeofday() call on platform without monotonic time.
*/
typedef struct {
nxt_realtime_t realtime;
nxt_nsec_t monotonic;
nxt_nsec_t update;
#if !(NXT_HAVE_CLOCK_MONOTONIC || NXT_SOLARIS || NXT_HPUX || NXT_MACOSX)
nxt_nsec_t previous;
#endif
} nxt_monotonic_time_t;
NXT_EXPORT void nxt_realtime(nxt_realtime_t *now);
NXT_EXPORT void nxt_monotonic_time(nxt_monotonic_time_t *now);
NXT_EXPORT void nxt_localtime(nxt_time_t s, struct tm *tm);
NXT_EXPORT void nxt_timezone_update(void);
/*
* Both localtime() and localtime_r() are not Async-Signal-Safe, therefore,
* they can not be used in signal handlers. Since Daylight Saving Time (DST)
* state changes no more than twice a year, a simple workaround is to use
* a previously cached GMT offset value and nxt_gmtime():
*
* nxt_gmtime(GMT seconds + GMT offset, tm);
*
* GMT offset with account of current DST state can be obtained only
* using localtime()'s struct tm because:
*
* 1) gettimeofday() does not return GMT offset at almost all platforms.
* MacOSX returns a value cached after the first localtime() call.
* AIX returns GMT offset without account of DST state and indicates
* only that timezone has DST, but does not indicate current DST state.
*
* 2) There are the "timezone" and "daylight" variables on Linux, Solaris,
* HP-UX, IRIX, and other systems. The "daylight" variable indicates
* only that timezone has DST, but does not indicate current DST state.
*
* 3) Solaris and IRIX have the "altzone" variable which contains GMT offset
* for timezone with DST applied, but without account of DST state.
*
* 4) There is the "struct tm.tm_gmtoff" field on BSD systems and modern Linux.
* This field contains GMT offset with account of DST state.
*
* 5) The "struct tm.tm_isdst" field returned by localtime() indicates
* current DST state on all platforms. This field may have three values:
* positive means DST in effect, zero means DST is not in effect, and
* negative means DST state is unknown.
*/
#if (NXT_HAVE_TM_GMTOFF)
#define nxt_timezone(tm) \
((tm)->tm_gmtoff)
#elif (NXT_HAVE_ALTZONE)
#define nxt_timezone(tm) \
(-(((tm)->tm_isdst > 0) ? altzone : timezone))
#else
#define nxt_timezone(tm) \
(-(((tm)->tm_isdst > 0) ? timezone + 3600 : timezone))
#endif
typedef uint32_t nxt_msec_t;
typedef int32_t nxt_msec_int_t;
#define NXT_INFINITE_MSEC ((nxt_msec_t) -1)
/*
* Since nxt_msec_t values are stored just in 32 bits, they overflow
* every 49 days. This signed subtraction takes into account that overflow.
* "nxt_msec_diff(m1, m2) < 0" means that m1 is lesser than m2.
*/
#define nxt_msec_diff(m1, m2) \
((int32_t) ((m1) - (m2)))
#endif /* _NXT_UNIX_TIME_H_INCLUDED_ */
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