Annotation of embedaddon/nginx/src/core/ngx_times.c, revision 1.1.1.1
1.1 misho 1:
2: /*
3: * Copyright (C) Igor Sysoev
4: * Copyright (C) Nginx, Inc.
5: */
6:
7:
8: #include <ngx_config.h>
9: #include <ngx_core.h>
10:
11:
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: */
20:
21: #define NGX_TIME_SLOTS 64
22:
23: static ngx_uint_t slot;
24: static ngx_atomic_t ngx_time_lock;
25:
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:
33: #if !(NGX_WIN32)
34:
35: /*
36: * localtime() and localtime_r() are not Async-Signal-Safe functions, therefore,
37: * they must not be called by a signal handler, so we use the cached
38: * GMT offset value. Fortunately the value is changed only two times a year.
39: */
40:
41: static ngx_int_t cached_gmtoff;
42: #endif
43:
44: static ngx_time_t cached_time[NGX_TIME_SLOTS];
45: static u_char cached_err_log_time[NGX_TIME_SLOTS]
46: [sizeof("1970/09/28 12:00:00")];
47: static u_char cached_http_time[NGX_TIME_SLOTS]
48: [sizeof("Mon, 28 Sep 1970 06:00:00 GMT")];
49: static u_char cached_http_log_time[NGX_TIME_SLOTS]
50: [sizeof("28/Sep/1970:12:00:00 +0600")];
51: static u_char cached_http_log_iso8601[NGX_TIME_SLOTS]
52: [sizeof("1970-09-28T12:00:00+06:00")];
53:
54:
55: static char *week[] = { "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" };
56: static char *months[] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun",
57: "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
58:
59: void
60: ngx_time_init(void)
61: {
62: ngx_cached_err_log_time.len = sizeof("1970/09/28 12:00:00") - 1;
63: ngx_cached_http_time.len = sizeof("Mon, 28 Sep 1970 06:00:00 GMT") - 1;
64: ngx_cached_http_log_time.len = sizeof("28/Sep/1970:12:00:00 +0600") - 1;
65: ngx_cached_http_log_iso8601.len = sizeof("1970-09-28T12:00:00+06:00") - 1;
66:
67: ngx_cached_time = &cached_time[0];
68:
69: ngx_time_update();
70: }
71:
72:
73: void
74: ngx_time_update(void)
75: {
76: u_char *p0, *p1, *p2, *p3;
77: ngx_tm_t tm, gmt;
78: time_t sec;
79: ngx_uint_t msec;
80: ngx_time_t *tp;
81: struct timeval tv;
82:
83: if (!ngx_trylock(&ngx_time_lock)) {
84: return;
85: }
86:
87: ngx_gettimeofday(&tv);
88:
89: sec = tv.tv_sec;
90: msec = tv.tv_usec / 1000;
91:
92: ngx_current_msec = (ngx_msec_t) sec * 1000 + msec;
93:
94: tp = &cached_time[slot];
95:
96: if (tp->sec == sec) {
97: tp->msec = msec;
98: ngx_unlock(&ngx_time_lock);
99: return;
100: }
101:
102: if (slot == NGX_TIME_SLOTS - 1) {
103: slot = 0;
104: } else {
105: slot++;
106: }
107:
108: tp = &cached_time[slot];
109:
110: tp->sec = sec;
111: tp->msec = msec;
112:
113: ngx_gmtime(sec, &gmt);
114:
115:
116: p0 = &cached_http_time[slot][0];
117:
118: (void) ngx_sprintf(p0, "%s, %02d %s %4d %02d:%02d:%02d GMT",
119: week[gmt.ngx_tm_wday], gmt.ngx_tm_mday,
120: months[gmt.ngx_tm_mon - 1], gmt.ngx_tm_year,
121: gmt.ngx_tm_hour, gmt.ngx_tm_min, gmt.ngx_tm_sec);
122:
123: #if (NGX_HAVE_GETTIMEZONE)
124:
125: tp->gmtoff = ngx_gettimezone();
126: ngx_gmtime(sec + tp->gmtoff * 60, &tm);
127:
128: #elif (NGX_HAVE_GMTOFF)
129:
130: ngx_localtime(sec, &tm);
131: cached_gmtoff = (ngx_int_t) (tm.ngx_tm_gmtoff / 60);
132: tp->gmtoff = cached_gmtoff;
133:
134: #else
135:
136: ngx_localtime(sec, &tm);
137: cached_gmtoff = ngx_timezone(tm.ngx_tm_isdst);
138: tp->gmtoff = cached_gmtoff;
139:
140: #endif
141:
142:
143: p1 = &cached_err_log_time[slot][0];
144:
145: (void) ngx_sprintf(p1, "%4d/%02d/%02d %02d:%02d:%02d",
146: tm.ngx_tm_year, tm.ngx_tm_mon,
147: tm.ngx_tm_mday, tm.ngx_tm_hour,
148: tm.ngx_tm_min, tm.ngx_tm_sec);
149:
150:
151: p2 = &cached_http_log_time[slot][0];
152:
153: (void) ngx_sprintf(p2, "%02d/%s/%d:%02d:%02d:%02d %c%02d%02d",
154: tm.ngx_tm_mday, months[tm.ngx_tm_mon - 1],
155: tm.ngx_tm_year, tm.ngx_tm_hour,
156: tm.ngx_tm_min, tm.ngx_tm_sec,
157: tp->gmtoff < 0 ? '-' : '+',
158: ngx_abs(tp->gmtoff / 60), ngx_abs(tp->gmtoff % 60));
159:
160: p3 = &cached_http_log_iso8601[slot][0];
161:
162: (void) ngx_sprintf(p3, "%4d-%02d-%02dT%02d:%02d:%02d%c%02d:%02d",
163: tm.ngx_tm_year, tm.ngx_tm_mon,
164: tm.ngx_tm_mday, tm.ngx_tm_hour,
165: tm.ngx_tm_min, tm.ngx_tm_sec,
166: tp->gmtoff < 0 ? '-' : '+',
167: ngx_abs(tp->gmtoff / 60), ngx_abs(tp->gmtoff % 60));
168:
169:
170: ngx_memory_barrier();
171:
172: ngx_cached_time = tp;
173: ngx_cached_http_time.data = p0;
174: ngx_cached_err_log_time.data = p1;
175: ngx_cached_http_log_time.data = p2;
176: ngx_cached_http_log_iso8601.data = p3;
177:
178: ngx_unlock(&ngx_time_lock);
179: }
180:
181:
182: #if !(NGX_WIN32)
183:
184: void
185: ngx_time_sigsafe_update(void)
186: {
187: u_char *p;
188: ngx_tm_t tm;
189: time_t sec;
190: ngx_time_t *tp;
191: struct timeval tv;
192:
193: if (!ngx_trylock(&ngx_time_lock)) {
194: return;
195: }
196:
197: ngx_gettimeofday(&tv);
198:
199: sec = tv.tv_sec;
200:
201: tp = &cached_time[slot];
202:
203: if (tp->sec == sec) {
204: ngx_unlock(&ngx_time_lock);
205: return;
206: }
207:
208: if (slot == NGX_TIME_SLOTS - 1) {
209: slot = 0;
210: } else {
211: slot++;
212: }
213:
214: tp = &cached_time[slot];
215:
216: tp->sec = 0;
217:
218: ngx_gmtime(sec + cached_gmtoff * 60, &tm);
219:
220: p = &cached_err_log_time[slot][0];
221:
222: (void) ngx_sprintf(p, "%4d/%02d/%02d %02d:%02d:%02d",
223: tm.ngx_tm_year, tm.ngx_tm_mon,
224: tm.ngx_tm_mday, tm.ngx_tm_hour,
225: tm.ngx_tm_min, tm.ngx_tm_sec);
226:
227: ngx_memory_barrier();
228:
229: ngx_cached_err_log_time.data = p;
230:
231: ngx_unlock(&ngx_time_lock);
232: }
233:
234: #endif
235:
236:
237: u_char *
238: ngx_http_time(u_char *buf, time_t t)
239: {
240: ngx_tm_t tm;
241:
242: ngx_gmtime(t, &tm);
243:
244: return ngx_sprintf(buf, "%s, %02d %s %4d %02d:%02d:%02d GMT",
245: week[tm.ngx_tm_wday],
246: tm.ngx_tm_mday,
247: months[tm.ngx_tm_mon - 1],
248: tm.ngx_tm_year,
249: tm.ngx_tm_hour,
250: tm.ngx_tm_min,
251: tm.ngx_tm_sec);
252: }
253:
254:
255: u_char *
256: ngx_http_cookie_time(u_char *buf, time_t t)
257: {
258: ngx_tm_t tm;
259:
260: ngx_gmtime(t, &tm);
261:
262: /*
263: * Netscape 3.x does not understand 4-digit years at all and
264: * 2-digit years more than "37"
265: */
266:
267: return ngx_sprintf(buf,
268: (tm.ngx_tm_year > 2037) ?
269: "%s, %02d-%s-%d %02d:%02d:%02d GMT":
270: "%s, %02d-%s-%02d %02d:%02d:%02d GMT",
271: week[tm.ngx_tm_wday],
272: tm.ngx_tm_mday,
273: months[tm.ngx_tm_mon - 1],
274: (tm.ngx_tm_year > 2037) ? tm.ngx_tm_year:
275: tm.ngx_tm_year % 100,
276: tm.ngx_tm_hour,
277: tm.ngx_tm_min,
278: tm.ngx_tm_sec);
279: }
280:
281:
282: void
283: ngx_gmtime(time_t t, ngx_tm_t *tp)
284: {
285: ngx_int_t yday;
286: ngx_uint_t n, sec, min, hour, mday, mon, year, wday, days, leap;
287:
288: /* the calculation is valid for positive time_t only */
289:
290: n = (ngx_uint_t) t;
291:
292: days = n / 86400;
293:
294: /* January 1, 1970 was Thursday */
295:
296: wday = (4 + days) % 7;
297:
298: n %= 86400;
299: hour = n / 3600;
300: n %= 3600;
301: min = n / 60;
302: sec = n % 60;
303:
304: /*
305: * the algorithm based on Gauss' formula,
306: * see src/http/ngx_http_parse_time.c
307: */
308:
309: /* days since March 1, 1 BC */
310: days = days - (31 + 28) + 719527;
311:
312: /*
313: * The "days" should be adjusted to 1 only, however, some March 1st's go
314: * to previous year, so we adjust them to 2. This causes also shift of the
315: * last February days to next year, but we catch the case when "yday"
316: * becomes negative.
317: */
318:
319: year = (days + 2) * 400 / (365 * 400 + 100 - 4 + 1);
320:
321: yday = days - (365 * year + year / 4 - year / 100 + year / 400);
322:
323: if (yday < 0) {
324: leap = (year % 4 == 0) && (year % 100 || (year % 400 == 0));
325: yday = 365 + leap + yday;
326: year--;
327: }
328:
329: /*
330: * The empirical formula that maps "yday" to month.
331: * There are at least 10 variants, some of them are:
332: * mon = (yday + 31) * 15 / 459
333: * mon = (yday + 31) * 17 / 520
334: * mon = (yday + 31) * 20 / 612
335: */
336:
337: mon = (yday + 31) * 10 / 306;
338:
339: /* the Gauss' formula that evaluates days before the month */
340:
341: mday = yday - (367 * mon / 12 - 30) + 1;
342:
343: if (yday >= 306) {
344:
345: year++;
346: mon -= 10;
347:
348: /*
349: * there is no "yday" in Win32 SYSTEMTIME
350: *
351: * yday -= 306;
352: */
353:
354: } else {
355:
356: mon += 2;
357:
358: /*
359: * there is no "yday" in Win32 SYSTEMTIME
360: *
361: * yday += 31 + 28 + leap;
362: */
363: }
364:
365: tp->ngx_tm_sec = (ngx_tm_sec_t) sec;
366: tp->ngx_tm_min = (ngx_tm_min_t) min;
367: tp->ngx_tm_hour = (ngx_tm_hour_t) hour;
368: tp->ngx_tm_mday = (ngx_tm_mday_t) mday;
369: tp->ngx_tm_mon = (ngx_tm_mon_t) mon;
370: tp->ngx_tm_year = (ngx_tm_year_t) year;
371: tp->ngx_tm_wday = (ngx_tm_wday_t) wday;
372: }
373:
374:
375: time_t
376: ngx_next_time(time_t when)
377: {
378: time_t now, next;
379: struct tm tm;
380:
381: now = ngx_time();
382:
383: ngx_libc_localtime(now, &tm);
384:
385: tm.tm_hour = (int) (when / 3600);
386: when %= 3600;
387: tm.tm_min = (int) (when / 60);
388: tm.tm_sec = (int) (when % 60);
389:
390: next = mktime(&tm);
391:
392: if (next == -1) {
393: return -1;
394: }
395:
396: if (next - now > 0) {
397: return next;
398: }
399:
400: tm.tm_mday++;
401:
402: /* mktime() should normalize a date (Jan 32, etc) */
403:
404: next = mktime(&tm);
405:
406: if (next != -1) {
407: return next;
408: }
409:
410: return -1;
411: }
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