quickjs-tart

quickjs-based runtime for wallet-core logic
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ares_timeval.c (3402B)

      1 /* MIT License
      2  *
      3  * Copyright (c) 2008 Daniel Stenberg
      4  *
      5  * Permission is hereby granted, free of charge, to any person obtaining a copy
      6  * of this software and associated documentation files (the "Software"), to deal
      7  * in the Software without restriction, including without limitation the rights
      8  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
      9  * copies of the Software, and to permit persons to whom the Software is
     10  * furnished to do so, subject to the following conditions:
     11  *
     12  * The above copyright notice and this permission notice (including the next
     13  * paragraph) shall be included in all copies or substantial portions of the
     14  * Software.
     15  *
     16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
     19  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
     20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
     21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
     22  * SOFTWARE.
     23  *
     24  * SPDX-License-Identifier: MIT
     25  */
     26 
     27 #include "ares_private.h"
     28 
     29 #if defined(_WIN32) && !defined(MSDOS)
     30 
     31 void ares_tvnow(ares_timeval_t *now)
     32 {
     33   /* QueryPerformanceCounters() has been around since Windows 2000, though
     34    * significant fixes were made in later versions.  Documentation states
     35    * 1 microsecond or better resolution with a rollover not less than 100 years.
     36    * This differs from GetTickCount{64}() which has a resolution between 10 and
     37    * 16 ms. */
     38   LARGE_INTEGER freq;
     39   LARGE_INTEGER current;
     40 
     41   /* Not sure how long it takes to get the frequency, I see it recommended to
     42    * cache it */
     43   QueryPerformanceFrequency(&freq);
     44   QueryPerformanceCounter(&current);
     45 
     46   now->sec = current.QuadPart / freq.QuadPart;
     47   /* We want to prevent overflows so we get the remainder, then multiply to
     48    * microseconds before dividing */
     49   now->usec = (unsigned int)(((current.QuadPart % freq.QuadPart) * 1000000) /
     50                              freq.QuadPart);
     51 }
     52 
     53 #elif defined(HAVE_CLOCK_GETTIME_MONOTONIC)
     54 
     55 void ares_tvnow(ares_timeval_t *now)
     56 {
     57   /* clock_gettime() is guaranteed to be increased monotonically when the
     58    * monotonic clock is queried. Time starting point is unspecified, it
     59    * could be the system start-up time, the Epoch, or something else,
     60    * in any case the time starting point does not change once that the
     61    * system has started up. */
     62   struct timespec tsnow;
     63 
     64   if (clock_gettime(CLOCK_MONOTONIC, &tsnow) == 0) {
     65     now->sec  = (ares_int64_t)tsnow.tv_sec;
     66     now->usec = (unsigned int)(tsnow.tv_nsec / 1000);
     67   } else {
     68     /* LCOV_EXCL_START: FallbackCode */
     69     struct timeval tv;
     70     (void)gettimeofday(&tv, NULL);
     71     now->sec  = (ares_int64_t)tv.tv_sec;
     72     now->usec = (unsigned int)tv.tv_usec;
     73     /* LCOV_EXCL_STOP */
     74   }
     75 }
     76 
     77 #elif defined(HAVE_GETTIMEOFDAY)
     78 
     79 void ares_tvnow(ares_timeval_t *now)
     80 {
     81   /* gettimeofday() is not granted to be increased monotonically, due to
     82    * clock drifting and external source time synchronization it can jump
     83    * forward or backward in time. */
     84   struct timeval tv;
     85 
     86   (void)gettimeofday(&tv, NULL);
     87   now->sec  = (ares_int64_t)tv.tv_sec;
     88   now->usec = (unsigned int)tv.tv_usec;
     89 }
     90 
     91 #else
     92 
     93 #  error missing sub-second time retrieval function
     94 
     95 #endif