| // <semaphore> -*- C++ -*- |
| |
| // Copyright (C) 2020-2021 Free Software Foundation, Inc. |
| // |
| // This file is part of the GNU ISO C++ Library. This library is free |
| // software; you can redistribute it and/or modify it under the |
| // terms of the GNU General Public License as published by the |
| // Free Software Foundation; either version 3, or (at your option) |
| // any later version. |
| |
| // This library is distributed in the hope that it will be useful, |
| // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| // GNU General Public License for more details. |
| |
| // Under Section 7 of GPL version 3, you are granted additional |
| // permissions described in the GCC Runtime Library Exception, version |
| // 3.1, as published by the Free Software Foundation. |
| |
| // You should have received a copy of the GNU General Public License and |
| // a copy of the GCC Runtime Library Exception along with this program; |
| // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| // <http://www.gnu.org/licenses/>. |
| |
| /** @file include/semaphore |
| * This is a Standard C++ Library header. |
| */ |
| |
| #ifndef _GLIBCXX_SEMAPHORE |
| #define _GLIBCXX_SEMAPHORE 1 |
| |
| #pragma GCC system_header |
| |
| #if __cplusplus > 201703L |
| #include <bits/semaphore_base.h> |
| |
| #if __cpp_lib_atomic_wait || _GLIBCXX_HAVE_POSIX_SEMAPHORE |
| namespace std _GLIBCXX_VISIBILITY(default) |
| { |
| _GLIBCXX_BEGIN_NAMESPACE_VERSION |
| |
| #define __cpp_lib_semaphore 201907L |
| |
| template<ptrdiff_t __least_max_value = __semaphore_impl::_S_max> |
| class counting_semaphore |
| { |
| static_assert(__least_max_value >= 0); |
| static_assert(__least_max_value <= __semaphore_impl::_S_max); |
| |
| __semaphore_impl _M_sem; |
| |
| public: |
| explicit counting_semaphore(ptrdiff_t __desired) noexcept |
| : _M_sem(__desired) |
| { } |
| |
| ~counting_semaphore() = default; |
| |
| counting_semaphore(const counting_semaphore&) = delete; |
| counting_semaphore& operator=(const counting_semaphore&) = delete; |
| |
| static constexpr ptrdiff_t |
| max() noexcept |
| { return __least_max_value; } |
| |
| void |
| release(ptrdiff_t __update = 1) noexcept(noexcept(_M_sem._M_release(1))) |
| { _M_sem._M_release(__update); } |
| |
| void |
| acquire() noexcept(noexcept(_M_sem._M_acquire())) |
| { _M_sem._M_acquire(); } |
| |
| bool |
| try_acquire() noexcept(noexcept(_M_sem._M_try_acquire())) |
| { return _M_sem._M_try_acquire(); } |
| |
| template<typename _Rep, typename _Period> |
| bool |
| try_acquire_for(const std::chrono::duration<_Rep, _Period>& __rtime) |
| { return _M_sem._M_try_acquire_for(__rtime); } |
| |
| template<typename _Clock, typename _Dur> |
| bool |
| try_acquire_until(const std::chrono::time_point<_Clock, _Dur>& __atime) |
| { return _M_sem._M_try_acquire_until(__atime); } |
| }; |
| |
| using binary_semaphore = std::counting_semaphore<1>; |
| |
| _GLIBCXX_END_NAMESPACE_VERSION |
| } // namespace |
| #endif // cpp_lib_atomic_wait || _GLIBCXX_HAVE_POSIX_SEMAPHORE |
| #endif // C++20 |
| #endif // _GLIBCXX_SEMAPHORE |