gcc/libstdc++-v3/include/bits/this_thread_sleep.h
2022-01-03 10:42:10 +01:00

118 lines
3.2 KiB
C++

// std::this_thread::sleep_for/until declarations -*- C++ -*-
// Copyright (C) 2008-2022 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 bits/this_thread_sleep.h
* This is an internal header file, included by other library headers.
* Do not attempt to use it directly. @headername{thread}
*/
#ifndef _GLIBCXX_THIS_THREAD_SLEEP_H
#define _GLIBCXX_THIS_THREAD_SLEEP_H 1
#pragma GCC system_header
#if __cplusplus >= 201103L
#include <bits/chrono.h> // std::chrono::*
#ifdef _GLIBCXX_USE_NANOSLEEP
# include <cerrno> // errno, EINTR
# include <time.h> // nanosleep
#endif
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
/** @addtogroup threads
* @{
*/
/** @namespace std::this_thread
* @brief ISO C++ 2011 namespace for interacting with the current thread
*
* C++11 30.3.2 [thread.thread.this] Namespace this_thread.
*/
namespace this_thread
{
#ifndef _GLIBCXX_NO_SLEEP
#ifndef _GLIBCXX_USE_NANOSLEEP
void
__sleep_for(chrono::seconds, chrono::nanoseconds);
#endif
/// this_thread::sleep_for
template<typename _Rep, typename _Period>
inline void
sleep_for(const chrono::duration<_Rep, _Period>& __rtime)
{
if (__rtime <= __rtime.zero())
return;
auto __s = chrono::duration_cast<chrono::seconds>(__rtime);
auto __ns = chrono::duration_cast<chrono::nanoseconds>(__rtime - __s);
#ifdef _GLIBCXX_USE_NANOSLEEP
struct ::timespec __ts =
{
static_cast<std::time_t>(__s.count()),
static_cast<long>(__ns.count())
};
while (::nanosleep(&__ts, &__ts) == -1 && errno == EINTR)
{ }
#else
__sleep_for(__s, __ns);
#endif
}
/// this_thread::sleep_until
template<typename _Clock, typename _Duration>
inline void
sleep_until(const chrono::time_point<_Clock, _Duration>& __atime)
{
#if __cplusplus > 201703L
static_assert(chrono::is_clock_v<_Clock>);
#endif
auto __now = _Clock::now();
if (_Clock::is_steady)
{
if (__now < __atime)
sleep_for(__atime - __now);
return;
}
while (__now < __atime)
{
sleep_for(__atime - __now);
__now = _Clock::now();
}
}
} // namespace this_thread
#endif // ! NO_SLEEP
/// @}
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#endif // C++11
#endif // _GLIBCXX_THIS_THREAD_SLEEP_H