1*b1e83836Smrg// <semaphore> -*- C++ -*- 2*b1e83836Smrg 3*b1e83836Smrg// Copyright (C) 2020-2022 Free Software Foundation, Inc. 4*b1e83836Smrg// 5*b1e83836Smrg// This file is part of the GNU ISO C++ Library. This library is free 6*b1e83836Smrg// software; you can redistribute it and/or modify it under the 7*b1e83836Smrg// terms of the GNU General Public License as published by the 8*b1e83836Smrg// Free Software Foundation; either version 3, or (at your option) 9*b1e83836Smrg// any later version. 10*b1e83836Smrg 11*b1e83836Smrg// This library is distributed in the hope that it will be useful, 12*b1e83836Smrg// but WITHOUT ANY WARRANTY; without even the implied warranty of 13*b1e83836Smrg// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14*b1e83836Smrg// GNU General Public License for more details. 15*b1e83836Smrg 16*b1e83836Smrg// Under Section 7 of GPL version 3, you are granted additional 17*b1e83836Smrg// permissions described in the GCC Runtime Library Exception, version 18*b1e83836Smrg// 3.1, as published by the Free Software Foundation. 19*b1e83836Smrg 20*b1e83836Smrg// You should have received a copy of the GNU General Public License and 21*b1e83836Smrg// a copy of the GCC Runtime Library Exception along with this program; 22*b1e83836Smrg// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 23*b1e83836Smrg// <http://www.gnu.org/licenses/>. 24*b1e83836Smrg 25*b1e83836Smrg/** @file include/semaphore 26*b1e83836Smrg * This is a Standard C++ Library header. 27*b1e83836Smrg */ 28*b1e83836Smrg 29*b1e83836Smrg#ifndef _GLIBCXX_SEMAPHORE 30*b1e83836Smrg#define _GLIBCXX_SEMAPHORE 1 31*b1e83836Smrg 32*b1e83836Smrg#pragma GCC system_header 33*b1e83836Smrg 34*b1e83836Smrg#if __cplusplus > 201703L 35*b1e83836Smrg#include <bits/semaphore_base.h> 36*b1e83836Smrg 37*b1e83836Smrg#if __cpp_lib_atomic_wait || _GLIBCXX_HAVE_POSIX_SEMAPHORE 38*b1e83836Smrgnamespace std _GLIBCXX_VISIBILITY(default) 39*b1e83836Smrg{ 40*b1e83836Smrg_GLIBCXX_BEGIN_NAMESPACE_VERSION 41*b1e83836Smrg 42*b1e83836Smrg#define __cpp_lib_semaphore 201907L 43*b1e83836Smrg 44*b1e83836Smrg template<ptrdiff_t __least_max_value = __semaphore_impl::_S_max> 45*b1e83836Smrg class counting_semaphore 46*b1e83836Smrg { 47*b1e83836Smrg static_assert(__least_max_value >= 0); 48*b1e83836Smrg static_assert(__least_max_value <= __semaphore_impl::_S_max); 49*b1e83836Smrg 50*b1e83836Smrg __semaphore_impl _M_sem; 51*b1e83836Smrg 52*b1e83836Smrg public: 53*b1e83836Smrg explicit counting_semaphore(ptrdiff_t __desired) noexcept 54*b1e83836Smrg : _M_sem(__desired) 55*b1e83836Smrg { } 56*b1e83836Smrg 57*b1e83836Smrg ~counting_semaphore() = default; 58*b1e83836Smrg 59*b1e83836Smrg counting_semaphore(const counting_semaphore&) = delete; 60*b1e83836Smrg counting_semaphore& operator=(const counting_semaphore&) = delete; 61*b1e83836Smrg 62*b1e83836Smrg static constexpr ptrdiff_t 63*b1e83836Smrg max() noexcept 64*b1e83836Smrg { return __least_max_value; } 65*b1e83836Smrg 66*b1e83836Smrg void 67*b1e83836Smrg release(ptrdiff_t __update = 1) noexcept(noexcept(_M_sem._M_release(1))) 68*b1e83836Smrg { _M_sem._M_release(__update); } 69*b1e83836Smrg 70*b1e83836Smrg void 71*b1e83836Smrg acquire() noexcept(noexcept(_M_sem._M_acquire())) 72*b1e83836Smrg { _M_sem._M_acquire(); } 73*b1e83836Smrg 74*b1e83836Smrg bool 75*b1e83836Smrg try_acquire() noexcept(noexcept(_M_sem._M_try_acquire())) 76*b1e83836Smrg { return _M_sem._M_try_acquire(); } 77*b1e83836Smrg 78*b1e83836Smrg template<typename _Rep, typename _Period> 79*b1e83836Smrg bool 80*b1e83836Smrg try_acquire_for(const std::chrono::duration<_Rep, _Period>& __rtime) 81*b1e83836Smrg { return _M_sem._M_try_acquire_for(__rtime); } 82*b1e83836Smrg 83*b1e83836Smrg template<typename _Clock, typename _Dur> 84*b1e83836Smrg bool 85*b1e83836Smrg try_acquire_until(const std::chrono::time_point<_Clock, _Dur>& __atime) 86*b1e83836Smrg { return _M_sem._M_try_acquire_until(__atime); } 87*b1e83836Smrg }; 88*b1e83836Smrg 89*b1e83836Smrg using binary_semaphore = std::counting_semaphore<1>; 90*b1e83836Smrg 91*b1e83836Smrg_GLIBCXX_END_NAMESPACE_VERSION 92*b1e83836Smrg} // namespace 93*b1e83836Smrg#endif // cpp_lib_atomic_wait || _GLIBCXX_HAVE_POSIX_SEMAPHORE 94*b1e83836Smrg#endif // C++20 95*b1e83836Smrg#endif // _GLIBCXX_SEMAPHORE 96