1 //===-- Implementation of gettimeofday function ---------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "src/time/gettimeofday.h" 10 #include "hdr/time_macros.h" 11 #include "hdr/types/suseconds_t.h" 12 #include "src/__support/common.h" 13 #include "src/__support/macros/config.h" 14 #include "src/__support/time/linux/clock_gettime.h" 15 #include "src/__support/time/units.h" 16 #include "src/errno/libc_errno.h" 17 18 namespace LIBC_NAMESPACE_DECL { 19 20 // TODO(michaelrj): Move this into time/linux with the other syscalls. 21 LLVM_LIBC_FUNCTION(int, gettimeofday, 22 (struct timeval * tv, [[maybe_unused]] void *unused)) { 23 using namespace time_units; 24 if (tv == nullptr) 25 return 0; 26 27 struct timespec ts; 28 auto result = internal::clock_gettime(CLOCK_REALTIME, &ts); 29 30 // A negative return value indicates an error with the magnitude of the 31 // value being the error code. 32 if (!result.has_value()) { 33 libc_errno = result.error(); 34 return -1; 35 } 36 37 tv->tv_sec = ts.tv_sec; 38 tv->tv_usec = static_cast<suseconds_t>(ts.tv_nsec / 1_us_ns); 39 return 0; 40 } 41 42 } // namespace LIBC_NAMESPACE_DECL 43