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src/core/ngx_times.c - nginx-1.7.10

Global variables defined

Functions defined

Macros defined

Source code


  2. /*
  3. * Copyright (C) Igor Sysoev
  4. * Copyright (C) Nginx, Inc.
  5. */


  8. #include <ngx_config.h>
  9. #include <ngx_core.h>


  12. /*
  13. * The time may be updated by signal handler or by several threads.
  14. * The time update operations are rare and require to hold the ngx_time_lock.
  15. * The time read operations are frequent, so they are lock-free and get time
  16. * values and strings from the current slot.  Thus thread may get the corrupted
  17. * values only if it is preempted while copying and then it is not scheduled
  18. * to run more than NGX_TIME_SLOTS seconds.
  19. */

  21. ‌#define NGX_TIME_SLOTS   64

  23. ‌static ngx_uint_t        slot;
  24. ‌static ngx_atomic_t      ngx_time_lock;

  26. ‌volatile ngx_msec_t      ngx_current_msec;
  27. ‌volatile ngx_time_t     *ngx_cached_time;
  28. ‌volatile ngx_str_t       ngx_cached_err_log_time;
  29. ‌volatile ngx_str_t       ngx_cached_http_time;
  30. ‌volatile ngx_str_t       ngx_cached_http_log_time;
  31. ‌volatile ngx_str_t       ngx_cached_http_log_iso8601;
  32. ‌volatile ngx_str_t       ngx_cached_syslog_time;

  34. #if !(NGX_WIN32)

  36. /*
  37. * localtime() and localtime_r() are not Async-Signal-Safe functions, therefore,
  38. * they must not be called by a signal handler, so we use the cached
  39. * GMT offset value. Fortunately the value is changed only two times a year.
  40. */

  42. ‌static ngx_int_t         cached_gmtoff;
  43. #endif

  45. ‌static ngx_time_t        cached_time[NGX_TIME_SLOTS];
  46. ‌static u_char            cached_err_log_time[NGX_TIME_SLOTS]
  47.                                     [sizeof("1970/09/28 12:00:00")];
  48. ‌static u_char            cached_http_time[NGX_TIME_SLOTS]
  49.                                     [sizeof("Mon, 28 Sep 1970 06:00:00 GMT")];
  50. ‌static u_char            cached_http_log_time[NGX_TIME_SLOTS]
  51.                                     [sizeof("28/Sep/1970:12:00:00 +0600")];
  52. ‌static u_char            cached_http_log_iso8601[NGX_TIME_SLOTS]
  53.                                     [sizeof("1970-09-28T12:00:00+06:00")];
  54. ‌static u_char            cached_syslog_time[NGX_TIME_SLOTS]
  55.                                     [sizeof("Sep 28 12:00:00")];


  58. ‌static char  *week[] = { "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" };
  59. ‌static char  *months[] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun",
  60.                            "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };

  62. void
  63. ‌ngx_time_init(void)
  64. {
  65.     ngx_cached_err_log_time.len = sizeof("1970/09/28 12:00:00") - 1;
  66.     ngx_cached_http_time.len = sizeof("Mon, 28 Sep 1970 06:00:00 GMT") - 1;
  67.     ngx_cached_http_log_time.len = sizeof("28/Sep/1970:12:00:00 +0600") - 1;
  68.     ngx_cached_http_log_iso8601.len = sizeof("1970-09-28T12:00:00+06:00") - 1;
  69.     ngx_cached_syslog_time.len = sizeof("Sep 28 12:00:00") - 1;

  71.     ngx_cached_time = &cached_time[0];

  73.     ngx_time_update();
  74. }


  77. void
  78. ‌ngx_time_update(void)
  79. {
  80.     u_char          *p0, *p1, *p2, *p3, *p4;
  81.     ngx_tm_t         tm, gmt;
  82.     time_t           sec;
  83.     ngx_uint_t       msec;
  84.     ngx_time_t      *tp;
  85.     struct timeval   tv;

  87.     if (!ngx_trylock(&ngx_time_lock)) {
  88.         return;
  89.     }

  91.     ngx_gettimeofday(&tv);

  93.     sec = tv.tv_sec;
  94.     msec = tv.tv_usec / 1000;

  96.     ngx_current_msec = (ngx_msec_t) sec * 1000 + msec;

  98.     tp = &cached_time[slot];

  100.     if (tp->sec == sec) {
  101.         tp->msec = msec;
  102.         ngx_unlock(&ngx_time_lock);
  103.         return;
  104.     }

  106.     if (slot == NGX_TIME_SLOTS - 1) {
  107.         slot = 0;
  108.     } else {
  109.         slot++;
  110.     }

  112.     tp = &cached_time[slot];

  114.     tp->sec = sec;
  115.     tp->msec = msec;

  117.     ngx_gmtime(sec, &gmt);


  120.     p0 = &cached_http_time[slot][0];

  122.     (void) ngx_sprintf(p0, "%s, %02d %s %4d %02d:%02d:%02d GMT",
  123.                        week[gmt.ngx_tm_wday], gmt.ngx_tm_mday,
  124.                        months[gmt.ngx_tm_mon - 1], gmt.ngx_tm_year,
  125.                        gmt.ngx_tm_hour, gmt.ngx_tm_min, gmt.ngx_tm_sec);

  127. #if (NGX_HAVE_GETTIMEZONE)

  129.     tp->gmtoff = ngx_gettimezone();
  130.     ngx_gmtime(sec + tp->gmtoff * 60, &tm);

  132. #elif (NGX_HAVE_GMTOFF)

  134.     ngx_localtime(sec, &tm);
  135.     cached_gmtoff = (ngx_int_t) (tm.ngx_tm_gmtoff / 60);
  136.     tp->gmtoff = cached_gmtoff;

  138. #else

  140.     ngx_localtime(sec, &tm);
  141.     cached_gmtoff = ngx_timezone(tm.ngx_tm_isdst);
  142.     tp->gmtoff = cached_gmtoff;

  144. #endif


  147.     p1 = &cached_err_log_time[slot][0];

  149.     (void) ngx_sprintf(p1, "%4d/%02d/%02d %02d:%02d:%02d",
  150.                        tm.ngx_tm_year, tm.ngx_tm_mon,
  151.                        tm.ngx_tm_mday, tm.ngx_tm_hour,
  152.                        tm.ngx_tm_min, tm.ngx_tm_sec);


  155.     p2 = &cached_http_log_time[slot][0];

  157.     (void) ngx_sprintf(p2, "%02d/%s/%d:%02d:%02d:%02d %c%02d%02d",
  158.                        tm.ngx_tm_mday, months[tm.ngx_tm_mon - 1],
  159.                        tm.ngx_tm_year, tm.ngx_tm_hour,
  160.                        tm.ngx_tm_min, tm.ngx_tm_sec,
  161.                        tp->gmtoff < 0 ? '-' : '+',
  162.                        ngx_abs(tp->gmtoff / 60), ngx_abs(tp->gmtoff % 60));

  164.     p3 = &cached_http_log_iso8601[slot][0];

  166.     (void) ngx_sprintf(p3, "%4d-%02d-%02dT%02d:%02d:%02d%c%02d:%02d",
  167.                        tm.ngx_tm_year, tm.ngx_tm_mon,
  168.                        tm.ngx_tm_mday, tm.ngx_tm_hour,
  169.                        tm.ngx_tm_min, tm.ngx_tm_sec,
  170.                        tp->gmtoff < 0 ? '-' : '+',
  171.                        ngx_abs(tp->gmtoff / 60), ngx_abs(tp->gmtoff % 60));

  173.     p4 = &cached_syslog_time[slot][0];

  175.     (void) ngx_sprintf(p4, "%s %2d %02d:%02d:%02d",
  176.                        months[tm.ngx_tm_mon - 1], tm.ngx_tm_mday,
  177.                        tm.ngx_tm_hour, tm.ngx_tm_min, tm.ngx_tm_sec);

  179.     ngx_memory_barrier();

  181.     ngx_cached_time = tp;
  182.     ngx_cached_http_time.data = p0;
  183.     ngx_cached_err_log_time.data = p1;
  184.     ngx_cached_http_log_time.data = p2;
  185.     ngx_cached_http_log_iso8601.data = p3;
  186.     ngx_cached_syslog_time.data = p4;

  188.     ngx_unlock(&ngx_time_lock);
  189. }


  192. #if !(NGX_WIN32)

  194. void
  195. ‌ngx_time_sigsafe_update(void)
  196. {
  197.     u_char          *p, *p2;
  198.     ngx_tm_t         tm;
  199.     time_t           sec;
  200.     ngx_time_t      *tp;
  201.     struct timeval   tv;

  203.     if (!ngx_trylock(&ngx_time_lock)) {
  204.         return;
  205.     }

  207.     ngx_gettimeofday(&tv);

  209.     sec = tv.tv_sec;

  211.     tp = &cached_time[slot];

  213.     if (tp->sec == sec) {
  214.         ngx_unlock(&ngx_time_lock);
  215.         return;
  216.     }

  218.     if (slot == NGX_TIME_SLOTS - 1) {
  219.         slot = 0;
  220.     } else {
  221.         slot++;
  222.     }

  224.     tp = &cached_time[slot];

  226.     tp->sec = 0;

  228.     ngx_gmtime(sec + cached_gmtoff * 60, &tm);

  230.     p = &cached_err_log_time[slot][0];

  232.     (void) ngx_sprintf(p, "%4d/%02d/%02d %02d:%02d:%02d",
  233.                        tm.ngx_tm_year, tm.ngx_tm_mon,
  234.                        tm.ngx_tm_mday, tm.ngx_tm_hour,
  235.                        tm.ngx_tm_min, tm.ngx_tm_sec);

  237.     p2 = &cached_syslog_time[slot][0];

  239.     (void) ngx_sprintf(p2, "%s %2d %02d:%02d:%02d",
  240.                        months[tm.ngx_tm_mon - 1], tm.ngx_tm_mday,
  241.                        tm.ngx_tm_hour, tm.ngx_tm_min, tm.ngx_tm_sec);

  243.     ngx_memory_barrier();

  245.     ngx_cached_err_log_time.data = p;
  246.     ngx_cached_syslog_time.data = p2;

  248.     ngx_unlock(&ngx_time_lock);
  249. }

  251. #endif


  254. u_char *
  255. ‌ngx_http_time(u_char *buf, time_t t)
  256. {
  257.     ngx_tm_t  tm;

  259.     ngx_gmtime(t, &tm);

  261.     return ngx_sprintf(buf, "%s, %02d %s %4d %02d:%02d:%02d GMT",
  262.                        week[tm.ngx_tm_wday],
  263.                        tm.ngx_tm_mday,
  264.                        months[tm.ngx_tm_mon - 1],
  265.                        tm.ngx_tm_year,
  266.                        tm.ngx_tm_hour,
  267.                        tm.ngx_tm_min,
  268.                        tm.ngx_tm_sec);
  269. }


  272. u_char *
  273. ‌ngx_http_cookie_time(u_char *buf, time_t t)
  274. {
  275.     ngx_tm_t  tm;

  277.     ngx_gmtime(t, &tm);

  279.     /*
  280.      * Netscape 3.x does not understand 4-digit years at all and
  281.      * 2-digit years more than "37"
  282.      */

  284.     return ngx_sprintf(buf,
  285.                        (tm.ngx_tm_year > 2037) ?
  286.                                          "%s, %02d-%s-%d %02d:%02d:%02d GMT":
  287.                                          "%s, %02d-%s-%02d %02d:%02d:%02d GMT",
  288.                        week[tm.ngx_tm_wday],
  289.                        tm.ngx_tm_mday,
  290.                        months[tm.ngx_tm_mon - 1],
  291.                        (tm.ngx_tm_year > 2037) ? tm.ngx_tm_year:
  292.                                                  tm.ngx_tm_year % 100,
  293.                        tm.ngx_tm_hour,
  294.                        tm.ngx_tm_min,
  295.                        tm.ngx_tm_sec);
  296. }


  299. void
  300. ‌ngx_gmtime(time_t t, ngx_tm_t *tp)
  301. {
  302.     ngx_int_t   yday;
  303.     ngx_uint_t  n, sec, min, hour, mday, mon, year, wday, days, leap;

  305.     /* the calculation is valid for positive time_t only */

  307.     n = (ngx_uint_t) t;

  309.     days = n / 86400;

  311.     /* January 1, 1970 was Thursday */

  313.     wday = (4 + days) % 7;

  315.     n %= 86400;
  316.     hour = n / 3600;
  317.     n %= 3600;
  318.     min = n / 60;
  319.     sec = n % 60;

  321.     /*
  322.      * the algorithm based on Gauss' formula,
  323.      * see src/http/ngx_http_parse_time.c
  324.      */

  326.     /* days since March 1, 1 BC */
  327.     days = days - (31 + 28) + 719527;

  329.     /*
  330.      * The "days" should be adjusted to 1 only, however, some March 1st's go
  331.      * to previous year, so we adjust them to 2.  This causes also shift of the
  332.      * last February days to next year, but we catch the case when "yday"
  333.      * becomes negative.
  334.      */

  336.     year = (days + 2) * 400 / (365 * 400 + 100 - 4 + 1);

  338.     yday = days - (365 * year + year / 4 - year / 100 + year / 400);

  340.     if (yday < 0) {
  341.         leap = (year % 4 == 0) && (year % 100 || (year % 400 == 0));
  342.         yday = 365 + leap + yday;
  343.         year--;
  344.     }

  346.     /*
  347.      * The empirical formula that maps "yday" to month.
  348.      * There are at least 10 variants, some of them are:
  349.      *     mon = (yday + 31) * 15 / 459
  350.      *     mon = (yday + 31) * 17 / 520
  351.      *     mon = (yday + 31) * 20 / 612
  352.      */

  354.     mon = (yday + 31) * 10 / 306;

  356.     /* the Gauss' formula that evaluates days before the month */

  358.     mday = yday - (367 * mon / 12 - 30) + 1;

  360.     if (yday >= 306) {

  362.         year++;
  363.         mon -= 10;

  365.         /*
  366.          * there is no "yday" in Win32 SYSTEMTIME
  367.          *
  368.          * yday -= 306;
  369.          */

  371.     } else {

  373.         mon += 2;

  375.         /*
  376.          * there is no "yday" in Win32 SYSTEMTIME
  377.          *
  378.          * yday += 31 + 28 + leap;
  379.          */
  380.     }

  382.     tp->ngx_tm_sec = (ngx_tm_sec_t) sec;
  383.     tp->ngx_tm_min = (ngx_tm_min_t) min;
  384.     tp->ngx_tm_hour = (ngx_tm_hour_t) hour;
  385.     tp->ngx_tm_mday = (ngx_tm_mday_t) mday;
  386.     tp->ngx_tm_mon = (ngx_tm_mon_t) mon;
  387.     tp->ngx_tm_year = (ngx_tm_year_t) year;
  388.     tp->ngx_tm_wday = (ngx_tm_wday_t) wday;
  389. }


  392. time_t
  393. ‌ngx_next_time(time_t when)
  394. {
  395.     time_t     now, next;
  396.     struct tm  tm;

  398.     now = ngx_time();

  400.     ngx_libc_localtime(now, &tm);

  402.     tm.tm_hour = (int) (when / 3600);
  403.     when %= 3600;
  404.     tm.tm_min = (int) (when / 60);
  405.     tm.tm_sec = (int) (when % 60);

  407.     next = mktime(&tm);

  409.     if (next == -1) {
  410.         return -1;
  411.     }

  413.     if (next - now > 0) {
  414.         return next;
  415.     }

  417.     tm.tm_mday++;

  419.     /* mktime() should normalize a date (Jan 32, etc) */

  421.     next = mktime(&tm);

  423.     if (next != -1) {
  424.         return next;
  425.     }

  427.     return -1;
  428. }

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