1 // -*- C++ -*- 2 //===----------------------------------------------------------------------===// 3 // 4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5 // See https://llvm.org/LICENSE.txt for license information. 6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef _LIBCPP___THREAD_THIS_THREAD_H 11 #define _LIBCPP___THREAD_THIS_THREAD_H 12 13 #include <__chrono/steady_clock.h> 14 #include <__chrono/time_point.h> 15 #include <__condition_variable/condition_variable.h> 16 #include <__config> 17 #include <__mutex/mutex.h> 18 #include <__mutex/unique_lock.h> 19 #include <__threading_support> 20 21 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 22 # pragma GCC system_header 23 #endif 24 25 _LIBCPP_PUSH_MACROS 26 #include <__undef_macros> 27 28 _LIBCPP_BEGIN_NAMESPACE_STD 29 30 namespace this_thread { 31 32 _LIBCPP_EXPORTED_FROM_ABI void sleep_for(const chrono::nanoseconds& __ns); 33 34 template <class _Rep, class _Period> 35 _LIBCPP_HIDE_FROM_ABI void sleep_for(const chrono::duration<_Rep, _Period>& __d) { 36 if (__d > chrono::duration<_Rep, _Period>::zero()) { 37 // The standard guarantees a 64bit signed integer resolution for nanoseconds, 38 // so use INT64_MAX / 1e9 as cut-off point. Use a constant to avoid <climits> 39 // and issues with long double folding on PowerPC with GCC. 40 _LIBCPP_CONSTEXPR chrono::duration<long double> __max = chrono::duration<long double>(9223372036.0L); 41 chrono::nanoseconds __ns; 42 if (__d < __max) { 43 __ns = chrono::duration_cast<chrono::nanoseconds>(__d); 44 if (__ns < __d) 45 ++__ns; 46 } else 47 __ns = chrono::nanoseconds::max(); 48 this_thread::sleep_for(__ns); 49 } 50 } 51 52 template <class _Clock, class _Duration> 53 _LIBCPP_HIDE_FROM_ABI void sleep_until(const chrono::time_point<_Clock, _Duration>& __t) { 54 mutex __mut; 55 condition_variable __cv; 56 unique_lock<mutex> __lk(__mut); 57 while (_Clock::now() < __t) 58 __cv.wait_until(__lk, __t); 59 } 60 61 template <class _Duration> 62 inline _LIBCPP_HIDE_FROM_ABI void sleep_until(const chrono::time_point<chrono::steady_clock, _Duration>& __t) { 63 this_thread::sleep_for(__t - chrono::steady_clock::now()); 64 } 65 66 inline _LIBCPP_HIDE_FROM_ABI void yield() _NOEXCEPT { __libcpp_thread_yield(); } 67 68 } // namespace this_thread 69 70 _LIBCPP_END_NAMESPACE_STD 71 72 _LIBCPP_POP_MACROS 73 74 #endif // _LIBCPP___THREAD_THIS_THREAD_H 75