cfbdc34f25
* include/std/mutex [_GLIBCXX_HAVE_TLS] (_Once_call): Remove. (call_once) [_GLIBCXX_HAVE_TLS]: Simplify by removing _Once_call. From-SVN: r241034
634 lines
16 KiB
C++
634 lines
16 KiB
C++
// <mutex> -*- C++ -*-
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// Copyright (C) 2003-2016 Free Software Foundation, Inc.
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//
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// This file is part of the GNU ISO C++ Library. This library is free
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// software; you can redistribute it and/or modify it under the
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// terms of the GNU General Public License as published by the
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// Free Software Foundation; either version 3, or (at your option)
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// any later version.
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// Under Section 7 of GPL version 3, you are granted additional
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// permissions described in the GCC Runtime Library Exception, version
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// 3.1, as published by the Free Software Foundation.
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// You should have received a copy of the GNU General Public License and
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// a copy of the GCC Runtime Library Exception along with this program;
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// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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// <http://www.gnu.org/licenses/>.
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/** @file include/mutex
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* This is a Standard C++ Library header.
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*/
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#ifndef _GLIBCXX_MUTEX
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#define _GLIBCXX_MUTEX 1
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#pragma GCC system_header
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#if __cplusplus < 201103L
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# include <bits/c++0x_warning.h>
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#else
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#include <tuple>
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#include <chrono>
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#include <exception>
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#include <type_traits>
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#include <functional>
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#include <system_error>
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#include <bits/std_mutex.h>
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#if ! _GTHREAD_USE_MUTEX_TIMEDLOCK
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# include <condition_variable>
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# include <thread>
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#endif
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#ifdef _GLIBCXX_USE_C99_STDINT_TR1
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namespace std _GLIBCXX_VISIBILITY(default)
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{
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_GLIBCXX_BEGIN_NAMESPACE_VERSION
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/**
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* @ingroup mutexes
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* @{
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*/
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#ifdef _GLIBCXX_HAS_GTHREADS
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// Common base class for std::recursive_mutex and std::recursive_timed_mutex
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class __recursive_mutex_base
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{
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protected:
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typedef __gthread_recursive_mutex_t __native_type;
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__recursive_mutex_base(const __recursive_mutex_base&) = delete;
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__recursive_mutex_base& operator=(const __recursive_mutex_base&) = delete;
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#ifdef __GTHREAD_RECURSIVE_MUTEX_INIT
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__native_type _M_mutex = __GTHREAD_RECURSIVE_MUTEX_INIT;
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__recursive_mutex_base() = default;
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#else
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__native_type _M_mutex;
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__recursive_mutex_base()
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{
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// XXX EAGAIN, ENOMEM, EPERM, EBUSY(may), EINVAL(may)
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__GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION(&_M_mutex);
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}
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~__recursive_mutex_base()
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{ __gthread_recursive_mutex_destroy(&_M_mutex); }
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#endif
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};
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/// The standard recursive mutex type.
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class recursive_mutex : private __recursive_mutex_base
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{
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public:
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typedef __native_type* native_handle_type;
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recursive_mutex() = default;
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~recursive_mutex() = default;
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recursive_mutex(const recursive_mutex&) = delete;
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recursive_mutex& operator=(const recursive_mutex&) = delete;
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void
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lock()
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{
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int __e = __gthread_recursive_mutex_lock(&_M_mutex);
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// EINVAL, EAGAIN, EBUSY, EINVAL, EDEADLK(may)
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if (__e)
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__throw_system_error(__e);
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}
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bool
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try_lock() noexcept
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{
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// XXX EINVAL, EAGAIN, EBUSY
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return !__gthread_recursive_mutex_trylock(&_M_mutex);
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}
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void
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unlock()
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{
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// XXX EINVAL, EAGAIN, EBUSY
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__gthread_recursive_mutex_unlock(&_M_mutex);
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}
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native_handle_type
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native_handle() noexcept
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{ return &_M_mutex; }
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};
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#if _GTHREAD_USE_MUTEX_TIMEDLOCK
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template<typename _Derived>
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class __timed_mutex_impl
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{
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protected:
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typedef chrono::high_resolution_clock __clock_t;
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template<typename _Rep, typename _Period>
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bool
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_M_try_lock_for(const chrono::duration<_Rep, _Period>& __rtime)
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{
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using chrono::steady_clock;
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auto __rt = chrono::duration_cast<steady_clock::duration>(__rtime);
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if (ratio_greater<steady_clock::period, _Period>())
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++__rt;
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return _M_try_lock_until(steady_clock::now() + __rt);
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}
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template<typename _Duration>
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bool
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_M_try_lock_until(const chrono::time_point<__clock_t,
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_Duration>& __atime)
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{
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auto __s = chrono::time_point_cast<chrono::seconds>(__atime);
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auto __ns = chrono::duration_cast<chrono::nanoseconds>(__atime - __s);
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__gthread_time_t __ts = {
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static_cast<std::time_t>(__s.time_since_epoch().count()),
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static_cast<long>(__ns.count())
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};
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return static_cast<_Derived*>(this)->_M_timedlock(__ts);
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}
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template<typename _Clock, typename _Duration>
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bool
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_M_try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime)
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{
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auto __rtime = __atime - _Clock::now();
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return _M_try_lock_until(__clock_t::now() + __rtime);
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}
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};
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/// The standard timed mutex type.
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class timed_mutex
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: private __mutex_base, public __timed_mutex_impl<timed_mutex>
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{
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public:
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typedef __native_type* native_handle_type;
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timed_mutex() = default;
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~timed_mutex() = default;
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timed_mutex(const timed_mutex&) = delete;
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timed_mutex& operator=(const timed_mutex&) = delete;
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void
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lock()
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{
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int __e = __gthread_mutex_lock(&_M_mutex);
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// EINVAL, EAGAIN, EBUSY, EINVAL, EDEADLK(may)
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if (__e)
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__throw_system_error(__e);
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}
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bool
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try_lock() noexcept
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{
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// XXX EINVAL, EAGAIN, EBUSY
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return !__gthread_mutex_trylock(&_M_mutex);
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}
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template <class _Rep, class _Period>
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bool
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try_lock_for(const chrono::duration<_Rep, _Period>& __rtime)
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{ return _M_try_lock_for(__rtime); }
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template <class _Clock, class _Duration>
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bool
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try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime)
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{ return _M_try_lock_until(__atime); }
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void
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unlock()
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{
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// XXX EINVAL, EAGAIN, EBUSY
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__gthread_mutex_unlock(&_M_mutex);
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}
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native_handle_type
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native_handle() noexcept
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{ return &_M_mutex; }
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private:
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friend class __timed_mutex_impl<timed_mutex>;
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bool
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_M_timedlock(const __gthread_time_t& __ts)
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{ return !__gthread_mutex_timedlock(&_M_mutex, &__ts); }
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};
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/// recursive_timed_mutex
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class recursive_timed_mutex
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: private __recursive_mutex_base,
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public __timed_mutex_impl<recursive_timed_mutex>
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{
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public:
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typedef __native_type* native_handle_type;
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recursive_timed_mutex() = default;
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~recursive_timed_mutex() = default;
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recursive_timed_mutex(const recursive_timed_mutex&) = delete;
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recursive_timed_mutex& operator=(const recursive_timed_mutex&) = delete;
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void
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lock()
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{
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int __e = __gthread_recursive_mutex_lock(&_M_mutex);
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// EINVAL, EAGAIN, EBUSY, EINVAL, EDEADLK(may)
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if (__e)
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__throw_system_error(__e);
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}
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bool
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try_lock() noexcept
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{
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// XXX EINVAL, EAGAIN, EBUSY
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return !__gthread_recursive_mutex_trylock(&_M_mutex);
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}
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template <class _Rep, class _Period>
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bool
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try_lock_for(const chrono::duration<_Rep, _Period>& __rtime)
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{ return _M_try_lock_for(__rtime); }
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template <class _Clock, class _Duration>
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bool
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try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime)
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{ return _M_try_lock_until(__atime); }
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void
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unlock()
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{
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// XXX EINVAL, EAGAIN, EBUSY
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__gthread_recursive_mutex_unlock(&_M_mutex);
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}
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native_handle_type
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native_handle() noexcept
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{ return &_M_mutex; }
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private:
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friend class __timed_mutex_impl<recursive_timed_mutex>;
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bool
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_M_timedlock(const __gthread_time_t& __ts)
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{ return !__gthread_recursive_mutex_timedlock(&_M_mutex, &__ts); }
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};
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#else // !_GTHREAD_USE_MUTEX_TIMEDLOCK
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/// timed_mutex
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class timed_mutex
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{
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mutex _M_mut;
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condition_variable _M_cv;
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bool _M_locked = false;
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public:
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timed_mutex() = default;
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~timed_mutex() { __glibcxx_assert( !_M_locked ); }
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timed_mutex(const timed_mutex&) = delete;
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timed_mutex& operator=(const timed_mutex&) = delete;
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void
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lock()
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{
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unique_lock<mutex> __lk(_M_mut);
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_M_cv.wait(__lk, [&]{ return !_M_locked; });
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_M_locked = true;
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}
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bool
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try_lock()
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{
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lock_guard<mutex> __lk(_M_mut);
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if (_M_locked)
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return false;
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_M_locked = true;
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return true;
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}
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template<typename _Rep, typename _Period>
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bool
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try_lock_for(const chrono::duration<_Rep, _Period>& __rtime)
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{
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unique_lock<mutex> __lk(_M_mut);
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if (!_M_cv.wait_for(__lk, __rtime, [&]{ return !_M_locked; }))
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return false;
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_M_locked = true;
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return true;
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}
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template<typename _Clock, typename _Duration>
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bool
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try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime)
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{
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unique_lock<mutex> __lk(_M_mut);
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if (!_M_cv.wait_until(__lk, __atime, [&]{ return !_M_locked; }))
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return false;
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_M_locked = true;
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return true;
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}
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void
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unlock()
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{
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lock_guard<mutex> __lk(_M_mut);
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__glibcxx_assert( _M_locked );
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_M_locked = false;
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_M_cv.notify_one();
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}
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};
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/// recursive_timed_mutex
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class recursive_timed_mutex
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{
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mutex _M_mut;
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condition_variable _M_cv;
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thread::id _M_owner;
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unsigned _M_count = 0;
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// Predicate type that tests whether the current thread can lock a mutex.
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struct _Can_lock
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{
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// Returns true if the mutex is unlocked or is locked by _M_caller.
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bool
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operator()() const noexcept
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{ return _M_mx->_M_count == 0 || _M_mx->_M_owner == _M_caller; }
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const recursive_timed_mutex* _M_mx;
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thread::id _M_caller;
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};
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public:
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recursive_timed_mutex() = default;
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~recursive_timed_mutex() { __glibcxx_assert( _M_count == 0 ); }
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recursive_timed_mutex(const recursive_timed_mutex&) = delete;
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recursive_timed_mutex& operator=(const recursive_timed_mutex&) = delete;
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void
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lock()
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{
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auto __id = this_thread::get_id();
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_Can_lock __can_lock{this, __id};
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unique_lock<mutex> __lk(_M_mut);
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_M_cv.wait(__lk, __can_lock);
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if (_M_count == -1u)
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__throw_system_error(EAGAIN); // [thread.timedmutex.recursive]/3
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_M_owner = __id;
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++_M_count;
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}
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bool
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try_lock()
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{
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auto __id = this_thread::get_id();
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_Can_lock __can_lock{this, __id};
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lock_guard<mutex> __lk(_M_mut);
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if (!__can_lock())
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return false;
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if (_M_count == -1u)
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return false;
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_M_owner = __id;
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++_M_count;
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return true;
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}
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template<typename _Rep, typename _Period>
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bool
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try_lock_for(const chrono::duration<_Rep, _Period>& __rtime)
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{
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auto __id = this_thread::get_id();
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_Can_lock __can_lock{this, __id};
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unique_lock<mutex> __lk(_M_mut);
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if (!_M_cv.wait_for(__lk, __rtime, __can_lock))
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return false;
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if (_M_count == -1u)
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return false;
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_M_owner = __id;
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++_M_count;
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return true;
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}
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template<typename _Clock, typename _Duration>
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bool
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try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime)
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{
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auto __id = this_thread::get_id();
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_Can_lock __can_lock{this, __id};
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unique_lock<mutex> __lk(_M_mut);
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if (!_M_cv.wait_until(__lk, __atime, __can_lock))
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return false;
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if (_M_count == -1u)
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return false;
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_M_owner = __id;
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++_M_count;
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return true;
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}
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void
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unlock()
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{
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lock_guard<mutex> __lk(_M_mut);
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__glibcxx_assert( _M_owner == this_thread::get_id() );
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__glibcxx_assert( _M_count > 0 );
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if (--_M_count == 0)
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{
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_M_owner = {};
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_M_cv.notify_one();
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}
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}
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};
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#endif
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#endif // _GLIBCXX_HAS_GTHREADS
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template<typename _Lock>
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inline unique_lock<_Lock>
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__try_to_lock(_Lock& __l)
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{ return unique_lock<_Lock>{__l, try_to_lock}; }
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template<int _Idx, bool _Continue = true>
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struct __try_lock_impl
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{
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template<typename... _Lock>
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static void
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__do_try_lock(tuple<_Lock&...>& __locks, int& __idx)
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{
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__idx = _Idx;
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auto __lock = std::__try_to_lock(std::get<_Idx>(__locks));
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if (__lock.owns_lock())
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{
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constexpr bool __cont = _Idx + 2 < sizeof...(_Lock);
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using __try_locker = __try_lock_impl<_Idx + 1, __cont>;
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__try_locker::__do_try_lock(__locks, __idx);
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if (__idx == -1)
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__lock.release();
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}
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}
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};
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template<int _Idx>
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struct __try_lock_impl<_Idx, false>
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{
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template<typename... _Lock>
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static void
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__do_try_lock(tuple<_Lock&...>& __locks, int& __idx)
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{
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__idx = _Idx;
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auto __lock = std::__try_to_lock(std::get<_Idx>(__locks));
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if (__lock.owns_lock())
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{
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__idx = -1;
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__lock.release();
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}
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}
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};
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/** @brief Generic try_lock.
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* @param __l1 Meets Mutex requirements (try_lock() may throw).
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* @param __l2 Meets Mutex requirements (try_lock() may throw).
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* @param __l3 Meets Mutex requirements (try_lock() may throw).
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* @return Returns -1 if all try_lock() calls return true. Otherwise returns
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* a 0-based index corresponding to the argument that returned false.
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* @post Either all arguments are locked, or none will be.
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*
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* Sequentially calls try_lock() on each argument.
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*/
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template<typename _Lock1, typename _Lock2, typename... _Lock3>
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int
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try_lock(_Lock1& __l1, _Lock2& __l2, _Lock3&... __l3)
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{
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int __idx;
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auto __locks = std::tie(__l1, __l2, __l3...);
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__try_lock_impl<0>::__do_try_lock(__locks, __idx);
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return __idx;
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}
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/** @brief Generic lock.
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* @param __l1 Meets Mutex requirements (try_lock() may throw).
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* @param __l2 Meets Mutex requirements (try_lock() may throw).
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* @param __l3 Meets Mutex requirements (try_lock() may throw).
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* @throw An exception thrown by an argument's lock() or try_lock() member.
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* @post All arguments are locked.
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*
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* All arguments are locked via a sequence of calls to lock(), try_lock()
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* and unlock(). If the call exits via an exception any locks that were
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* obtained will be released.
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|
*/
|
|
template<typename _L1, typename _L2, typename... _L3>
|
|
void
|
|
lock(_L1& __l1, _L2& __l2, _L3&... __l3)
|
|
{
|
|
while (true)
|
|
{
|
|
using __try_locker = __try_lock_impl<0, sizeof...(_L3) != 0>;
|
|
unique_lock<_L1> __first(__l1);
|
|
int __idx;
|
|
auto __locks = std::tie(__l2, __l3...);
|
|
__try_locker::__do_try_lock(__locks, __idx);
|
|
if (__idx == -1)
|
|
{
|
|
__first.release();
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
#ifdef _GLIBCXX_HAS_GTHREADS
|
|
/// once_flag
|
|
struct once_flag
|
|
{
|
|
private:
|
|
typedef __gthread_once_t __native_type;
|
|
__native_type _M_once = __GTHREAD_ONCE_INIT;
|
|
|
|
public:
|
|
/// Constructor
|
|
constexpr once_flag() noexcept = default;
|
|
|
|
/// Deleted copy constructor
|
|
once_flag(const once_flag&) = delete;
|
|
/// Deleted assignment operator
|
|
once_flag& operator=(const once_flag&) = delete;
|
|
|
|
template<typename _Callable, typename... _Args>
|
|
friend void
|
|
call_once(once_flag& __once, _Callable&& __f, _Args&&... __args);
|
|
};
|
|
|
|
#ifdef _GLIBCXX_HAVE_TLS
|
|
extern __thread void* __once_callable;
|
|
extern __thread void (*__once_call)();
|
|
#else
|
|
extern function<void()> __once_functor;
|
|
|
|
extern void
|
|
__set_once_functor_lock_ptr(unique_lock<mutex>*);
|
|
|
|
extern mutex&
|
|
__get_once_mutex();
|
|
#endif
|
|
|
|
extern "C" void __once_proxy(void);
|
|
|
|
/// call_once
|
|
template<typename _Callable, typename... _Args>
|
|
void
|
|
call_once(once_flag& __once, _Callable&& __f, _Args&&... __args)
|
|
{
|
|
// _GLIBCXX_RESOLVE_LIB_DEFECTS
|
|
// 2442. call_once() shouldn't DECAY_COPY()
|
|
auto __callable = [&] {
|
|
std::__invoke(std::forward<_Callable>(__f),
|
|
std::forward<_Args>(__args)...);
|
|
};
|
|
#ifdef _GLIBCXX_HAVE_TLS
|
|
__once_callable = std::__addressof(__callable);
|
|
__once_call = []{ (*(decltype(__callable)*)__once_callable)(); };
|
|
#else
|
|
unique_lock<mutex> __functor_lock(__get_once_mutex());
|
|
__once_functor = __callable;
|
|
__set_once_functor_lock_ptr(&__functor_lock);
|
|
#endif
|
|
|
|
int __e = __gthread_once(&__once._M_once, &__once_proxy);
|
|
|
|
#ifndef _GLIBCXX_HAVE_TLS
|
|
if (__functor_lock)
|
|
__set_once_functor_lock_ptr(0);
|
|
#endif
|
|
|
|
if (__e)
|
|
__throw_system_error(__e);
|
|
}
|
|
#endif // _GLIBCXX_HAS_GTHREADS
|
|
|
|
// @} group mutexes
|
|
_GLIBCXX_END_NAMESPACE_VERSION
|
|
} // namespace
|
|
#endif // _GLIBCXX_USE_C99_STDINT_TR1
|
|
|
|
#endif // C++11
|
|
|
|
#endif // _GLIBCXX_MUTEX
|