X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=src%2Futil%2Ftime.c;h=799c6cc6323fafc935dfca05e6bfbd2c629027a5;hb=0778ffa854d2bb626ebedfe3c1e8ca6a1209e42e;hp=5e9a01b0948fb60c228b0f063a6876b5d2ca2caa;hpb=3d7fefedc9ba60bd8e8448efe8b628446d958536;p=oweals%2Fgnunet.git diff --git a/src/util/time.c b/src/util/time.c index 5e9a01b09..799c6cc63 100644 --- a/src/util/time.c +++ b/src/util/time.c @@ -1,21 +1,21 @@ /* This file is part of GNUnet. - (C) 2001-2013 Christian Grothoff (and other contributing authors) + Copyright (C) 2001-2013, 2018 GNUnet e.V. - GNUnet is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published - by the Free Software Foundation; either version 3, or (at your - option) any later version. + GNUnet is free software: you can redistribute it and/or modify it + under the terms of the GNU Affero General Public License as published + by the Free Software Foundation, either version 3 of the License, + or (at your option) any later version. GNUnet is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - General Public License for more details. + Affero General Public License for more details. - You should have received a copy of the GNU General Public License - along with GNUnet; see the file COPYING. If not, write to the - Free Software Foundation, Inc., 59 Temple Place - Suite 330, - Boston, MA 02111-1307, USA. + You should have received a copy of the GNU Affero General Public License + along with this program. If not, see . + + SPDX-License-Identifier: AGPL3.0-or-later */ /** @@ -24,9 +24,20 @@ * @brief functions for handling time and time arithmetic */ #include "platform.h" -#include "gnunet_time_lib.h" - -#define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__) +#include "gnunet_util_lib.h" +#if __STDC_NO_ATOMICS__ +#define ATOMIC +#else +#ifdef HAVE_STDATOMIC_H +#include +#define ATOMIC _Atomic +#else +#define __STDC_NO_ATOMICS__ 1 +#define ATOMIC +#endif +#endif + +#define LOG(kind,...) GNUNET_log_from (kind, "util-time", __VA_ARGS__) /** * Variable used to simulate clock skew. Used for testing, never in production. @@ -50,13 +61,53 @@ GNUNET_TIME_set_offset (long long offset) * * @return the offset we currently skew the locale time by */ -long long +long long GNUNET_TIME_get_offset () { return timestamp_offset; } +/** + * Round a time value so that it is suitable for transmission + * via JSON encodings. + * + * @param at time to round + * @return #GNUNET_OK if time was already rounded, #GNUNET_NO if + * it was just now rounded + */ +int +GNUNET_TIME_round_abs (struct GNUNET_TIME_Absolute *at) +{ + if (at->abs_value_us == GNUNET_TIME_UNIT_FOREVER_ABS.abs_value_us) + return GNUNET_OK; + if (0 == at->abs_value_us % 1000000) + return GNUNET_OK; + at->abs_value_us -= at->abs_value_us % 1000000; + return GNUNET_NO; +} + + +/** + * Round a time value so that it is suitable for transmission + * via JSON encodings. + * + * @param rt time to round + * @return #GNUNET_OK if time was already rounded, #GNUNET_NO if + * it was just now rounded + */ +int +GNUNET_TIME_round_rel (struct GNUNET_TIME_Relative *rt) +{ + if (rt->rel_value_us == GNUNET_TIME_UNIT_FOREVER_REL.rel_value_us) + return GNUNET_OK; + if (0 == rt->rel_value_us % 1000000) + return GNUNET_OK; + rt->rel_value_us -= rt->rel_value_us % 1000000; + return GNUNET_NO; +} + + /** * Get the current time (works just as "time", just that we use the * unit of time that the cron-jobs use (and is 64 bit)). @@ -108,6 +159,7 @@ struct GNUNET_TIME_Relative GNUNET_TIME_relative_get_unit_ () { static struct GNUNET_TIME_Relative one = { 1 }; + return one; } @@ -119,6 +171,7 @@ struct GNUNET_TIME_Relative GNUNET_TIME_relative_get_millisecond_ () { static struct GNUNET_TIME_Relative one = { 1000 }; + return one; } @@ -130,6 +183,7 @@ struct GNUNET_TIME_Relative GNUNET_TIME_relative_get_second_ () { static struct GNUNET_TIME_Relative one = { 1000 * 1000LL }; + return one; } @@ -141,6 +195,7 @@ struct GNUNET_TIME_Relative GNUNET_TIME_relative_get_minute_ () { static struct GNUNET_TIME_Relative one = { 60 * 1000 * 1000LL }; + return one; } @@ -152,6 +207,7 @@ struct GNUNET_TIME_Relative GNUNET_TIME_relative_get_hour_ () { static struct GNUNET_TIME_Relative one = { 60 * 60 * 1000 * 1000LL }; + return one; } @@ -163,9 +219,11 @@ struct GNUNET_TIME_Relative GNUNET_TIME_relative_get_forever_ () { static struct GNUNET_TIME_Relative forever = { UINT64_MAX }; + return forever; } + /** * Return "forever". */ @@ -176,6 +234,7 @@ GNUNET_TIME_absolute_get_forever_ () return forever; } + /** * Convert relative time to an absolute time in the * future. @@ -308,7 +367,7 @@ GNUNET_TIME_absolute_get_difference (struct GNUNET_TIME_Absolute start, * Get the duration of an operation as the * difference of the current time and the given start time "whence". * - * @return aborts if whence==FOREVER, 0 if whence > now, otherwise now-whence. + * @return 0 if whence > now, otherwise now-whence. */ struct GNUNET_TIME_Relative GNUNET_TIME_absolute_get_duration (struct GNUNET_TIME_Absolute whence) @@ -317,7 +376,6 @@ GNUNET_TIME_absolute_get_duration (struct GNUNET_TIME_Absolute whence) struct GNUNET_TIME_Relative ret; now = GNUNET_TIME_absolute_get (); - GNUNET_assert (whence.abs_value_us != UINT64_MAX); if (whence.abs_value_us > now.abs_value_us) return GNUNET_TIME_UNIT_ZERO; ret.rel_value_us = now.abs_value_us - whence.abs_value_us; @@ -379,13 +437,15 @@ GNUNET_TIME_absolute_subtract (struct GNUNET_TIME_Absolute start, */ struct GNUNET_TIME_Relative GNUNET_TIME_relative_multiply (struct GNUNET_TIME_Relative rel, - unsigned int factor) + unsigned long long factor) { struct GNUNET_TIME_Relative ret; if (0 == factor) return GNUNET_TIME_UNIT_ZERO; - ret.rel_value_us = rel.rel_value_us * (unsigned long long) factor; + if (rel.rel_value_us == GNUNET_TIME_UNIT_FOREVER_REL.rel_value_us) + return GNUNET_TIME_UNIT_FOREVER_REL; + ret.rel_value_us = rel.rel_value_us * factor; if (ret.rel_value_us / factor != rel.rel_value_us) { GNUNET_break (0); @@ -395,6 +455,65 @@ GNUNET_TIME_relative_multiply (struct GNUNET_TIME_Relative rel, } +/** + * Multiply relative time by a given floating-point factor. The factor must be + * positive. + * + * @return FOREVER if rel=FOREVER or on overflow; otherwise rel*factor + */ +struct GNUNET_TIME_Relative +relative_multiply_double (struct GNUNET_TIME_Relative rel, + double factor) +{ + struct GNUNET_TIME_Relative out; + double m; + + GNUNET_assert (0 <= factor); + + if (0 == factor) + return GNUNET_TIME_UNIT_ZERO; + if (rel.rel_value_us == GNUNET_TIME_UNIT_FOREVER_REL.rel_value_us) + return GNUNET_TIME_UNIT_FOREVER_REL; + + m = ((double) rel.rel_value_us) * factor; + + if (m >= (double) (GNUNET_TIME_UNIT_FOREVER_REL).rel_value_us) + { + GNUNET_break (0); + return GNUNET_TIME_UNIT_FOREVER_REL; + } + + out.rel_value_us = (uint64_t) m; + return out; +} + + +/** + * Saturating multiply relative time by a given factor. + * + * @param rel some duration + * @param factor integer to multiply with + * @return FOREVER if rel=FOREVER or on overflow; otherwise rel*factor + */ +struct GNUNET_TIME_Relative +GNUNET_TIME_relative_saturating_multiply (struct GNUNET_TIME_Relative rel, + unsigned long long factor) +{ + struct GNUNET_TIME_Relative ret; + + if (0 == factor) + return GNUNET_TIME_UNIT_ZERO; + if (rel.rel_value_us == GNUNET_TIME_UNIT_FOREVER_REL.rel_value_us) + return GNUNET_TIME_UNIT_FOREVER_REL; + ret.rel_value_us = rel.rel_value_us * factor; + if (ret.rel_value_us / factor != rel.rel_value_us) + { + return GNUNET_TIME_UNIT_FOREVER_REL; + } + return ret; +} + + /** * Divide relative time by a given factor. * @@ -404,14 +523,14 @@ GNUNET_TIME_relative_multiply (struct GNUNET_TIME_Relative rel, */ struct GNUNET_TIME_Relative GNUNET_TIME_relative_divide (struct GNUNET_TIME_Relative rel, - unsigned int factor) + unsigned long long factor) { struct GNUNET_TIME_Relative ret; if ((0 == factor) || (rel.rel_value_us == GNUNET_TIME_UNIT_FOREVER_REL.rel_value_us)) return GNUNET_TIME_UNIT_FOREVER_REL; - ret.rel_value_us = rel.rel_value_us / (unsigned long long) factor; + ret.rel_value_us = rel.rel_value_us / factor; return ret; } @@ -522,7 +641,6 @@ GNUNET_TIME_relative_ntoh (struct GNUNET_TIME_RelativeNBO a) ret.rel_value_us = GNUNET_ntohll (a.rel_value_us__); return ret; - } @@ -559,4 +677,244 @@ GNUNET_TIME_absolute_ntoh (struct GNUNET_TIME_AbsoluteNBO a) } +/** + * Return the current year (i.e. '2011'). + */ +unsigned int +GNUNET_TIME_get_current_year () +{ + time_t tp; + struct tm *t; + + tp = time (NULL); + t = gmtime (&tp); + if (t == NULL) + return 0; + return t->tm_year + 1900; +} + + +/** + * Convert an expiration time to the respective year (rounds) + * + * @param at absolute time + * @return year a year (after 1970), 0 on error + */ +unsigned int +GNUNET_TIME_time_to_year (struct GNUNET_TIME_Absolute at) +{ + struct tm *t; + time_t tp; + + tp = at.abs_value_us / 1000LL / 1000LL; /* microseconds to seconds */ + t = gmtime (&tp); + if (t == NULL) + return 0; + return t->tm_year + 1900; + +} + + +/** + * Convert a year to an expiration time of January 1st of that year. + * + * @param year a year (after 1970, please ;-)). + * @return absolute time for January 1st of that year. + */ +struct GNUNET_TIME_Absolute +GNUNET_TIME_year_to_time (unsigned int year) +{ + struct GNUNET_TIME_Absolute ret; + time_t tp; + struct tm t; + + memset (&t, 0, sizeof (t)); + if (year < 1900) + { + GNUNET_break (0); + return GNUNET_TIME_absolute_get (); /* now */ + } + t.tm_year = year - 1900; + t.tm_mday = 1; + t.tm_mon = 0; + t.tm_wday = 1; + t.tm_yday = 1; + tp = mktime (&t); + GNUNET_break (tp != (time_t) - 1); + ret.abs_value_us = tp * 1000LL * 1000LL; /* seconds to microseconds */ + return ret; +} + + +/** + * Randomized exponential back-off, starting at 1 ms + * and going up by a factor of 2+r, where 0 <= r <= 0.5, up + * to a maximum of the given threshold. + * + * @param r current backoff time, initially zero + * @param threshold maximum value for backoff + * @return the next backoff time + */ +struct GNUNET_TIME_Relative +GNUNET_TIME_randomized_backoff(struct GNUNET_TIME_Relative rt, struct GNUNET_TIME_Relative threshold) +{ + double r = (rand() % 500) / 1000.0; + struct GNUNET_TIME_Relative t; + + t = relative_multiply_double (GNUNET_TIME_relative_max (GNUNET_TIME_UNIT_MILLISECONDS, + rt), + 2 + r); + return GNUNET_TIME_relative_min (threshold, + t); +} + + +/** + * Obtain the current time and make sure it is monotonically + * increasing. Guards against systems without an RTC or + * clocks running backwards and other nasty surprises. Does + * not guarantee that the returned time is near the current + * time returned by #GNUNET_TIME_absolute_get(). Two + * subsequent calls (within a short time period) may return the + * same value. Persists the last returned time on disk to + * ensure that time never goes backwards. As a result, the + * resulting value can be used to check if a message is the + * "most recent" value and replays of older messages (from + * the same origin) would be discarded. + * + * @param cfg configuration, used to determine where to + * store the time; user can also insist RTC is working + * nicely and disable the feature + * @return monotonically increasing time + */ +struct GNUNET_TIME_Absolute +GNUNET_TIME_absolute_get_monotonic (const struct GNUNET_CONFIGURATION_Handle *cfg) +{ + static const struct GNUNET_CONFIGURATION_Handle *last_cfg; + static struct GNUNET_TIME_Absolute last_time; + static struct GNUNET_DISK_MapHandle *map_handle; + static ATOMIC volatile uint64_t *map; + struct GNUNET_TIME_Absolute now; + + now = GNUNET_TIME_absolute_get (); + if (last_cfg != cfg) + { + char *filename; + + if (NULL != map_handle) + { + GNUNET_DISK_file_unmap (map_handle); + map_handle = NULL; + } + map = NULL; + + last_cfg = cfg; + if ( (NULL != cfg) && + (GNUNET_OK == + GNUNET_CONFIGURATION_get_value_filename (cfg, + "util", + "MONOTONIC_TIME_FILENAME", + &filename)) ) + { + struct GNUNET_DISK_FileHandle *fh; + + fh = GNUNET_DISK_file_open (filename, + GNUNET_DISK_OPEN_READWRITE | GNUNET_DISK_OPEN_CREATE, + GNUNET_DISK_PERM_USER_WRITE | GNUNET_DISK_PERM_GROUP_WRITE | + GNUNET_DISK_PERM_USER_READ | GNUNET_DISK_PERM_GROUP_READ); + if (NULL == fh) + { + GNUNET_log (GNUNET_ERROR_TYPE_WARNING, + _("Failed to map `%s', cannot assure monotonic time!\n"), + filename); + } + else + { + off_t size; + + size = 0; + GNUNET_break (GNUNET_OK == + GNUNET_DISK_file_handle_size (fh, + &size)); + if (size < sizeof (*map)) + { + struct GNUNET_TIME_AbsoluteNBO o; + + o = GNUNET_TIME_absolute_hton (now); + if (sizeof (o) != + GNUNET_DISK_file_write (fh, + &o, + sizeof (o))) + size = 0; + else + size = sizeof (o); + } + if (size == sizeof (*map)) + { + map = GNUNET_DISK_file_map (fh, + &map_handle, + GNUNET_DISK_MAP_TYPE_READWRITE, + sizeof (*map)); + if (NULL == map) + GNUNET_log (GNUNET_ERROR_TYPE_WARNING, + _("Failed to map `%s', cannot assure monotonic time!\n"), + filename); + } + else + { + GNUNET_log (GNUNET_ERROR_TYPE_WARNING, + _("Failed to setup monotonic time file `%s', cannot assure monotonic time!\n"), + filename); + } + } + GNUNET_DISK_file_close (fh); + GNUNET_free (filename); + } + } + if (NULL != map) + { + struct GNUNET_TIME_AbsoluteNBO mt; + +#if __STDC_NO_ATOMICS__ +#if __GNUC__ + mt.abs_value_us__ = __sync_fetch_and_or (map, 0); +#else + mt.abs_value_us__ = *map; /* godspeed, pray this is atomic */ +#endif +#else + mt.abs_value_us__ = atomic_load (map); +#endif + last_time = GNUNET_TIME_absolute_max (GNUNET_TIME_absolute_ntoh (mt), + last_time); + } + if (now.abs_value_us <= last_time.abs_value_us) + now.abs_value_us = last_time.abs_value_us+1; + last_time = now; + if (NULL != map) + { + uint64_t val = GNUNET_TIME_absolute_hton (now).abs_value_us__; +#if __STDC_NO_ATOMICS__ +#if __GNUC__ + (void) __sync_lock_test_and_set (map, val); +#else + *map = val; /* godspeed, pray this is atomic */ +#endif +#else + atomic_store (map, + val); +#endif + } + return now; +} + + +/** + * Destructor + */ +void __attribute__ ((destructor)) +GNUNET_util_time_fini () +{ + (void) GNUNET_TIME_absolute_get_monotonic (NULL); +} + /* end of time.c */