2 * Copyright 2016 Facebook, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 #include <folly/portability/SysTime.h>
24 int gettimeofday(timeval* tv, timezone*) {
25 constexpr auto posixWinFtOffset = 116444736000000000ULL;
30 GetSystemTimeAsFileTime(&ft);
31 // As per the docs of FILETIME, don't just do an indirect
32 // pointer cast, to avoid alignment faults.
33 lft.HighPart = ft.dwHighDateTime;
34 lft.LowPart = ft.dwLowDateTime;
35 uint64_t ns = lft.QuadPart;
36 tv->tv_usec = (long)((ns / 10ULL) % 1000000ULL);
37 tv->tv_sec = (long)((ns - posixWinFtOffset) / 10000000ULL);
43 void timeradd(timeval* a, timeval* b, timeval* res) {
44 res->tv_sec = a->tv_sec + b->tv_sec;
45 res->tv_usec = a->tv_usec + b->tv_usec;
46 if (res->tv_usec >= 1000000) {
48 res->tv_usec -= 1000000;
52 void timersub(timeval* a, timeval* b, timeval* res) {
53 res->tv_sec = a->tv_sec - b->tv_sec;
54 res->tv_usec = a->tv_usec - b->tv_usec;
55 if (res->tv_usec < 0) {
57 res->tv_usec += 1000000;