4b2db80771
This removes the #error from <bits/semaphore_base.h> for the case where neither __atomic_semaphore nor __platform_semaphore is defined. Also rename the _GLIBCXX_REQUIRE_POSIX_SEMAPHORE macro to _GLIBCXX_USE_POSIX_SEMAPHORE for consistency with the similar _GLIBCXX_USE_CXX11_ABI macro that can be used to request an alternative (ABI-changing) implementation. libstdc++-v3/ChangeLog: PR libstdc++/100179 * include/bits/semaphore_base.h: Remove #error. * include/std/semaphore: Do not define anything unless one of the implementations is available.
96 lines
2.9 KiB
C++
96 lines
2.9 KiB
C++
// <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
|