src/common/time.c

   1 /*
   2  * Copyright (C) 2013 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License, version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 51
  15  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #include <common/time.h>
  19 #include <common/macros.h>
  20 #include <stddef.h>
  21 #include <stdint.h>
  22 #include <limits.h>
  23 #include <errno.h>
  24 #include <pthread.h>
  25 #include <locale.h>
  26 #include <string.h>
  27
  28 static bool utf8_output_supported;
  29
  30 LTTNG_HIDDEN
  31 bool locale_supports_utf8(void)
  32 {
  33         return utf8_output_supported;
  34 }
  35
  36 LTTNG_HIDDEN
  37 int timespec_to_ms(struct timespec ts, unsigned long *ms)
  38 {
  39         unsigned long res, remain_ms;
  40
  41         if (ts.tv_sec > ULONG_MAX / MSEC_PER_SEC) {
  42                 errno = EOVERFLOW;
  43                 return -1;      /* multiplication overflow */
  44         }
  45         res = ts.tv_sec * MSEC_PER_SEC;
  46         remain_ms = ULONG_MAX - res;
  47         if (ts.tv_nsec / NSEC_PER_MSEC > remain_ms) {
  48                 errno = EOVERFLOW;
  49                 return -1;      /* addition overflow */
  50         }
  51         res += ts.tv_nsec / NSEC_PER_MSEC;
  52         *ms = res;
  53         return 0;
  54 }
  55
  56 LTTNG_HIDDEN
  57 struct timespec timespec_abs_diff(struct timespec t1, struct timespec t2)
  58 {
  59         uint64_t ts1 = (uint64_t) t1.tv_sec * (uint64_t) NSEC_PER_SEC +
  60                         (uint64_t) t1.tv_nsec;
  61         uint64_t ts2 = (uint64_t) t2.tv_sec * (uint64_t) NSEC_PER_SEC +
  62                         (uint64_t) t2.tv_nsec;
  63         uint64_t diff = max(ts1, ts2) - min(ts1, ts2);
  64         struct timespec res;
  65
  66         res.tv_sec = diff / (uint64_t) NSEC_PER_SEC;
  67         res.tv_nsec = diff % (uint64_t) NSEC_PER_SEC;
  68         return res;
  69 }
  70
  71 static
  72 void __attribute__((constructor)) init_locale_utf8_support(void)
  73 {
  74         const char *program_locale = setlocale(LC_ALL, NULL);
  75         const char *lang = getenv("LANG");
  76
  77         if (program_locale && strstr(program_locale, "utf8")) {
  78                 utf8_output_supported = true;
  79         } else if (lang && strstr(lang, "utf8")) {
  80                 utf8_output_supported = true;
  81         }
  82 }