// <mutex> -*- C++ -*-
-// Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008
+// Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2013
// 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 2, or (at your option)
+// 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,
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
-// You should have received a copy of the GNU General Public License
-// along with this library; see the file COPYING. If not, write to
-// the Free Software Foundation, 51 Franklin Street, Fifth Floor,
-// Boston, MA 02110-1301, USA.
-
-// As a special exception, you may use this file as part of a free software
-// library without restriction. Specifically, if other files instantiate
-// templates or use macros or inline functions from this file, or you compile
-// this file and link it with other files to produce an executable, this
-// file does not by itself cause the resulting executable to be covered by
-// the GNU General Public License. This exception does not however
-// invalidate any other reasons why the executable file might be covered by
-// the GNU General Public License.
-
-/** @file mutex
+// 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/mutex
* This is a Standard C++ Library header.
*/
#pragma GCC system_header
#ifndef __GXX_EXPERIMENTAL_CXX0X__
-# include <c++0x_warning.h>
-#endif
+# include <bits/c++0x_warning.h>
+#else
+#include <tuple>
+#include <chrono>
#include <exception>
-#include <cstddef>
+#include <type_traits>
+#include <functional>
+#include <system_error>
#include <bits/functexcept.h>
#include <bits/gthr.h>
+#include <bits/move.h> // for std::swap
-namespace std
+#ifdef _GLIBCXX_USE_C99_STDINT_TR1
+
+namespace std _GLIBCXX_VISIBILITY(default)
{
- // XXX
- class system_time;
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
- /// mutex
- class mutex
+#ifdef _GLIBCXX_HAS_GTHREADS
+ // Common base class for std::mutex and std::timed_mutex
+ class __mutex_base
{
- public:
- typedef __gthread_mutex_t native_handle_type;
+ protected:
+ typedef __gthread_mutex_t __native_type;
- mutex()
- {
-#if defined __GTHREAD_MUTEX_INIT
- native_handle_type __tmp = __GTHREAD_MUTEX_INIT;
- _M_mutex = __tmp;
+#ifdef __GTHREAD_MUTEX_INIT
+ __native_type _M_mutex = __GTHREAD_MUTEX_INIT;
+
+ constexpr __mutex_base() noexcept = default;
#else
+ __native_type _M_mutex;
+
+ __mutex_base() noexcept
+ {
+ // XXX EAGAIN, ENOMEM, EPERM, EBUSY(may), EINVAL(may)
__GTHREAD_MUTEX_INIT_FUNCTION(&_M_mutex);
+ }
+
+ ~__mutex_base() noexcept { __gthread_mutex_destroy(&_M_mutex); }
#endif
- // EAGAIN, ENOMEM, EPERM, EBUSY(may), EINVAL(may)
+ __mutex_base(const __mutex_base&) = delete;
+ __mutex_base& operator=(const __mutex_base&) = delete;
+ };
+
+ // Common base class for std::recursive_mutex and std::timed_recursive_mutex
+ class __recursive_mutex_base
+ {
+ protected:
+ typedef __gthread_recursive_mutex_t __native_type;
+
+ __recursive_mutex_base(const __recursive_mutex_base&) = delete;
+ __recursive_mutex_base& operator=(const __recursive_mutex_base&) = delete;
+
+#ifdef __GTHREAD_RECURSIVE_MUTEX_INIT
+ __native_type _M_mutex = __GTHREAD_RECURSIVE_MUTEX_INIT;
+
+ __recursive_mutex_base() = default;
+#else
+ __native_type _M_mutex;
+
+ __recursive_mutex_base()
+ {
+ // XXX EAGAIN, ENOMEM, EPERM, EBUSY(may), EINVAL(may)
+ __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION(&_M_mutex);
}
+ ~__recursive_mutex_base()
+ { _S_destroy(&_M_mutex); }
+
+ private:
+ // FIXME: gthreads doesn't define __gthread_recursive_mutex_destroy
+ // so we need to obtain a __gthread_mutex_t to destroy
+
+ // matches when there's only one mutex type
+ template<typename _Rm>
+ static
+ typename enable_if<is_same<_Rm, __gthread_mutex_t>::value, void>::type
+ _S_destroy(_Rm* __mx)
+ { __gthread_mutex_destroy(__mx); }
+
+ // matches a recursive mutex with a member 'actual'
+ template<typename _Rm>
+ static typename enable_if<(bool)sizeof(&_Rm::actual), void>::type
+ _S_destroy(_Rm* __mx)
+ { __gthread_mutex_destroy(&__mx->actual); }
+
+ // matches a gthr-win32.h recursive mutex
+ template<typename _Rm>
+ static typename enable_if<(bool)sizeof(&_Rm::sema), void>::type
+ _S_destroy(_Rm* __mx)
+ {
+ __gthread_mutex_t __tmp;
+ _S_destroy_win32(&__tmp, __mx);
+ }
+
+ template<typename _Mx, typename _Rm>
+ static void
+ _S_destroy_win32(_Mx* __mx, _Rm const* __rmx)
+ {
+ __mx->counter = __rmx->counter;
+ __mx->sema = __rmx->sema;
+ __gthread_mutex_destroy(__mx);
+ }
+#endif
+ };
+
+ /**
+ * @defgroup mutexes Mutexes
+ * @ingroup concurrency
+ *
+ * Classes for mutex support.
+ * @{
+ */
+
+ /// mutex
+ class mutex : private __mutex_base
+ {
+ public:
+ typedef __native_type* native_handle_type;
+
+#ifdef __GTHREAD_MUTEX_INIT
+ constexpr
+#endif
+ mutex() noexcept = default;
+ ~mutex() = default;
+
+ mutex(const mutex&) = delete;
+ mutex& operator=(const mutex&) = delete;
+
void
lock()
{
int __e = __gthread_mutex_lock(&_M_mutex);
// EINVAL, EAGAIN, EBUSY, EINVAL, EDEADLK(may)
- if (__e)
- __throw_system_error(__e);
+ if (__e)
+ __throw_system_error(__e);
}
bool
- try_lock()
+ try_lock() noexcept
{
- int __e = __gthread_mutex_trylock(&_M_mutex);
-
- // EINVAL, EAGAIN, EBUSY
- if (__e)
- __throw_system_error(__e);
- else
- return true;
+ // XXX EINVAL, EAGAIN, EBUSY
+ return !__gthread_mutex_trylock(&_M_mutex);
}
void
unlock()
{
- int __e = __gthread_mutex_unlock(&_M_mutex);
-
- // EINVAL, EAGAIN, EPERM
- if (__e)
- __throw_system_error(__e);
+ // XXX EINVAL, EAGAIN, EPERM
+ __gthread_mutex_unlock(&_M_mutex);
}
native_handle_type
native_handle()
- { return _M_mutex; }
-
- private:
- native_handle_type _M_mutex;
- mutex(const mutex&);
- mutex& operator=(const mutex&);
+ { return &_M_mutex; }
};
-
/// recursive_mutex
- class recursive_mutex
+ class recursive_mutex : private __recursive_mutex_base
{
public:
- typedef __gthread_recursive_mutex_t native_handle_type;
+ typedef __native_type* native_handle_type;
+
+ recursive_mutex() = default;
+ ~recursive_mutex() = default;
+
+ recursive_mutex(const recursive_mutex&) = delete;
+ recursive_mutex& operator=(const recursive_mutex&) = delete;
+
+ void
+ lock()
+ {
+ int __e = __gthread_recursive_mutex_lock(&_M_mutex);
+
+ // EINVAL, EAGAIN, EBUSY, EINVAL, EDEADLK(may)
+ if (__e)
+ __throw_system_error(__e);
+ }
- recursive_mutex()
+ bool
+ try_lock() noexcept
{
-#if defined __GTHREAD_RECURSIVE_MUTEX_INIT
- native_handle_type __tmp = __GTHREAD_RECURSIVE_MUTEX_INIT;
- _M_mutex = __tmp;
+ // XXX EINVAL, EAGAIN, EBUSY
+ return !__gthread_recursive_mutex_trylock(&_M_mutex);
+ }
+
+ void
+ unlock()
+ {
+ // XXX EINVAL, EAGAIN, EBUSY
+ __gthread_recursive_mutex_unlock(&_M_mutex);
+ }
+
+ native_handle_type
+ native_handle()
+ { return &_M_mutex; }
+ };
+
+#if _GTHREAD_USE_MUTEX_TIMEDLOCK
+ /// timed_mutex
+ class timed_mutex : private __mutex_base
+ {
+#ifdef _GLIBCXX_USE_CLOCK_MONOTONIC
+ typedef chrono::steady_clock __clock_t;
#else
- __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION(&_M_mutex);
+ typedef chrono::high_resolution_clock __clock_t;
#endif
- // EAGAIN, ENOMEM, EPERM, EBUSY(may), EINVAL(may)
+ public:
+ typedef __native_type* native_handle_type;
+
+ timed_mutex() = default;
+ ~timed_mutex() = default;
+
+ timed_mutex(const timed_mutex&) = delete;
+ timed_mutex& operator=(const timed_mutex&) = delete;
+
+ void
+ lock()
+ {
+ int __e = __gthread_mutex_lock(&_M_mutex);
+
+ // EINVAL, EAGAIN, EBUSY, EINVAL, EDEADLK(may)
+ if (__e)
+ __throw_system_error(__e);
}
+ bool
+ try_lock() noexcept
+ {
+ // XXX EINVAL, EAGAIN, EBUSY
+ return !__gthread_mutex_trylock(&_M_mutex);
+ }
+
+ template <class _Rep, class _Period>
+ bool
+ try_lock_for(const chrono::duration<_Rep, _Period>& __rtime)
+ { return __try_lock_for_impl(__rtime); }
+
+ template <class _Clock, class _Duration>
+ bool
+ try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime)
+ {
+ chrono::time_point<_Clock, chrono::seconds> __s =
+ chrono::time_point_cast<chrono::seconds>(__atime);
+
+ chrono::nanoseconds __ns =
+ chrono::duration_cast<chrono::nanoseconds>(__atime - __s);
+
+ __gthread_time_t __ts = {
+ static_cast<std::time_t>(__s.time_since_epoch().count()),
+ static_cast<long>(__ns.count())
+ };
+
+ return !__gthread_mutex_timedlock(&_M_mutex, &__ts);
+ }
+
+ void
+ unlock()
+ {
+ // XXX EINVAL, EAGAIN, EBUSY
+ __gthread_mutex_unlock(&_M_mutex);
+ }
+
+ native_handle_type
+ native_handle()
+ { return &_M_mutex; }
+
+ private:
+ template<typename _Rep, typename _Period>
+ typename enable_if<
+ ratio_less_equal<__clock_t::period, _Period>::value, bool>::type
+ __try_lock_for_impl(const chrono::duration<_Rep, _Period>& __rtime)
+ {
+ __clock_t::time_point __atime = __clock_t::now()
+ + chrono::duration_cast<__clock_t::duration>(__rtime);
+
+ return try_lock_until(__atime);
+ }
+
+ template <typename _Rep, typename _Period>
+ typename enable_if<
+ !ratio_less_equal<__clock_t::period, _Period>::value, bool>::type
+ __try_lock_for_impl(const chrono::duration<_Rep, _Period>& __rtime)
+ {
+ __clock_t::time_point __atime = __clock_t::now()
+ + ++chrono::duration_cast<__clock_t::duration>(__rtime);
+
+ return try_lock_until(__atime);
+ }
+ };
+
+ /// recursive_timed_mutex
+ class recursive_timed_mutex : private __recursive_mutex_base
+ {
+#ifdef _GLIBCXX_USE_CLOCK_MONOTONIC
+ typedef chrono::steady_clock __clock_t;
+#else
+ typedef chrono::high_resolution_clock __clock_t;
+#endif
+
+ public:
+ typedef __native_type* native_handle_type;
+
+ recursive_timed_mutex() = default;
+ ~recursive_timed_mutex() = default;
+
+ recursive_timed_mutex(const recursive_timed_mutex&) = delete;
+ recursive_timed_mutex& operator=(const recursive_timed_mutex&) = delete;
void
lock()
int __e = __gthread_recursive_mutex_lock(&_M_mutex);
// EINVAL, EAGAIN, EBUSY, EINVAL, EDEADLK(may)
- if (__e)
- __throw_system_error(__e);
+ if (__e)
+ __throw_system_error(__e);
}
bool
- try_lock()
+ try_lock() noexcept
{
- int __e = __gthread_recursive_mutex_trylock(&_M_mutex);
-
- // EINVAL, EAGAIN, EBUSY
- if (__e)
- __throw_system_error(__e);
- else
- return true;
+ // XXX EINVAL, EAGAIN, EBUSY
+ return !__gthread_recursive_mutex_trylock(&_M_mutex);
}
+ template <class _Rep, class _Period>
+ bool
+ try_lock_for(const chrono::duration<_Rep, _Period>& __rtime)
+ { return __try_lock_for_impl(__rtime); }
+
+ template <class _Clock, class _Duration>
+ bool
+ try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime)
+ {
+ chrono::time_point<_Clock, chrono::seconds> __s =
+ chrono::time_point_cast<chrono::seconds>(__atime);
+
+ chrono::nanoseconds __ns =
+ chrono::duration_cast<chrono::nanoseconds>(__atime - __s);
+
+ __gthread_time_t __ts = {
+ static_cast<std::time_t>(__s.time_since_epoch().count()),
+ static_cast<long>(__ns.count())
+ };
+
+ return !__gthread_recursive_mutex_timedlock(&_M_mutex, &__ts);
+ }
+
void
unlock()
{
- int __e = __gthread_recursive_mutex_unlock(&_M_mutex);
-
- // EINVAL, EAGAIN, EBUSY
- if (__e)
- __throw_system_error(__e);
+ // XXX EINVAL, EAGAIN, EBUSY
+ __gthread_recursive_mutex_unlock(&_M_mutex);
}
native_handle_type
- native_handle() { return _M_mutex; }
+ native_handle()
+ { return &_M_mutex; }
private:
- native_handle_type _M_mutex;
+ template<typename _Rep, typename _Period>
+ typename enable_if<
+ ratio_less_equal<__clock_t::period, _Period>::value, bool>::type
+ __try_lock_for_impl(const chrono::duration<_Rep, _Period>& __rtime)
+ {
+ __clock_t::time_point __atime = __clock_t::now()
+ + chrono::duration_cast<__clock_t::duration>(__rtime);
- recursive_mutex(const recursive_mutex&);
- recursive_mutex& operator=(const recursive_mutex&);
- };
+ return try_lock_until(__atime);
+ }
+ template <typename _Rep, typename _Period>
+ typename enable_if<
+ !ratio_less_equal<__clock_t::period, _Period>::value, bool>::type
+ __try_lock_for_impl(const chrono::duration<_Rep, _Period>& __rtime)
+ {
+ __clock_t::time_point __atime = __clock_t::now()
+ + ++chrono::duration_cast<__clock_t::duration>(__rtime);
- // class timed_mutex;
- // class recursive_timed_mutex;
+ return try_lock_until(__atime);
+ }
+ };
+#endif
+#endif // _GLIBCXX_HAS_GTHREADS
/// Do not acquire ownership of the mutex.
struct defer_lock_t { };
/// and manage it.
struct adopt_lock_t { };
- extern const defer_lock_t defer_lock;
- extern const try_to_lock_t try_to_lock;
- extern const adopt_lock_t adopt_lock;
-
- /// Thrown to indicate errors with lock operations.
- class lock_error : public exception
- {
- public:
- virtual const char*
- what() const throw();
- };
+ constexpr defer_lock_t defer_lock { };
+ constexpr try_to_lock_t try_to_lock { };
+ constexpr adopt_lock_t adopt_lock { };
/// @brief Scoped lock idiom.
// Acquire the mutex here with a constructor call, then release with
explicit lock_guard(mutex_type& __m) : _M_device(__m)
{ _M_device.lock(); }
- lock_guard(mutex_type& __m, adopt_lock_t __a) : _M_device(__m)
- { _M_device.lock(); }
+ lock_guard(mutex_type& __m, adopt_lock_t) : _M_device(__m)
+ { } // calling thread owns mutex
~lock_guard()
{ _M_device.unlock(); }
+ lock_guard(const lock_guard&) = delete;
+ lock_guard& operator=(const lock_guard&) = delete;
+
private:
mutex_type& _M_device;
- lock_guard(lock_guard const&);
- lock_guard& operator=(lock_guard const&);
};
/// unique_lock
public:
typedef _Mutex mutex_type;
- unique_lock() : _M_device(NULL), _M_owns(false) { }
+ unique_lock() noexcept
+ : _M_device(0), _M_owns(false)
+ { }
- explicit unique_lock(mutex_type& __m) : _M_device(&__m)
+ explicit unique_lock(mutex_type& __m)
+ : _M_device(&__m), _M_owns(false)
{
lock();
_M_owns = true;
}
- unique_lock(mutex_type& __m, defer_lock_t)
- : _M_device(&__m), _M_owns(false) { }
+ unique_lock(mutex_type& __m, defer_lock_t) noexcept
+ : _M_device(&__m), _M_owns(false)
+ { }
unique_lock(mutex_type& __m, try_to_lock_t)
- : _M_device(&__m), _M_owns(_M_device->try_lock()) { }
+ : _M_device(&__m), _M_owns(_M_device->try_lock())
+ { }
unique_lock(mutex_type& __m, adopt_lock_t)
: _M_device(&__m), _M_owns(true)
// XXX calling thread owns mutex
}
- unique_lock(mutex_type& __m, const system_time& abs_time);
+ template<typename _Clock, typename _Duration>
+ unique_lock(mutex_type& __m,
+ const chrono::time_point<_Clock, _Duration>& __atime)
+ : _M_device(&__m), _M_owns(_M_device->try_lock_until(__atime))
+ { }
- template<typename _Duration>
- unique_lock(mutex_type& __m, const _Duration& rel_time);
+ template<typename _Rep, typename _Period>
+ unique_lock(mutex_type& __m,
+ const chrono::duration<_Rep, _Period>& __rtime)
+ : _M_device(&__m), _M_owns(_M_device->try_lock_for(__rtime))
+ { }
~unique_lock()
{
unlock();
}
- unique_lock(unique_lock&&);
+ unique_lock(const unique_lock&) = delete;
+ unique_lock& operator=(const unique_lock&) = delete;
- unique_lock& operator=(unique_lock&&);
+ unique_lock(unique_lock&& __u) noexcept
+ : _M_device(__u._M_device), _M_owns(__u._M_owns)
+ {
+ __u._M_device = 0;
+ __u._M_owns = false;
+ }
+ unique_lock& operator=(unique_lock&& __u) noexcept
+ {
+ if(_M_owns)
+ unlock();
+
+ unique_lock(std::move(__u)).swap(*this);
+
+ __u._M_device = 0;
+ __u._M_owns = false;
+
+ return *this;
+ }
void
lock()
{
- if (_M_device && !_M_owns)
- _M_device->lock();
+ if (!_M_device)
+ __throw_system_error(int(errc::operation_not_permitted));
+ else if (_M_owns)
+ __throw_system_error(int(errc::resource_deadlock_would_occur));
else
- throw lock_error();
+ {
+ _M_device->lock();
+ _M_owns = true;
+ }
}
bool
try_lock()
{
- bool __ret = false;
- if (_M_device && !_M_owns)
- __ret = _M_device->try_lock();
+ if (!_M_device)
+ __throw_system_error(int(errc::operation_not_permitted));
+ else if (_M_owns)
+ __throw_system_error(int(errc::resource_deadlock_would_occur));
else
- throw lock_error();
- return __ret;
+ {
+ _M_owns = _M_device->try_lock();
+ return _M_owns;
+ }
}
+ template<typename _Clock, typename _Duration>
+ bool
+ try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime)
+ {
+ if (!_M_device)
+ __throw_system_error(int(errc::operation_not_permitted));
+ else if (_M_owns)
+ __throw_system_error(int(errc::resource_deadlock_would_occur));
+ else
+ {
+ _M_owns = _M_device->try_lock_until(__atime);
+ return _M_owns;
+ }
+ }
+
+ template<typename _Rep, typename _Period>
+ bool
+ try_lock_for(const chrono::duration<_Rep, _Period>& __rtime)
+ {
+ if (!_M_device)
+ __throw_system_error(int(errc::operation_not_permitted));
+ else if (_M_owns)
+ __throw_system_error(int(errc::resource_deadlock_would_occur));
+ else
+ {
+ _M_owns = _M_device->try_lock_for(__rtime);
+ return _M_owns;
+ }
+ }
+
void
unlock()
{
- if (_M_device && _M_owns)
- _M_device->unlock();
- else
- throw lock_error();
+ if (!_M_owns)
+ __throw_system_error(int(errc::operation_not_permitted));
+ else if (_M_device)
+ {
+ _M_device->unlock();
+ _M_owns = false;
+ }
}
-
- template<typename _Duration>
- bool timed_lock(const _Duration& rel_time);
-
- bool
- timed_lock(const system_time& abs_time);
-
void
- swap(unique_lock&& __u);
+ swap(unique_lock& __u) noexcept
+ {
+ std::swap(_M_device, __u._M_device);
+ std::swap(_M_owns, __u._M_owns);
+ }
mutex_type*
- release()
+ release() noexcept
{
mutex_type* __ret = _M_device;
- _M_device = NULL;
+ _M_device = 0;
_M_owns = false;
return __ret;
}
bool
- owns_lock() const { return _M_owns; }
+ owns_lock() const noexcept
+ { return _M_owns; }
- operator bool () const { return owns_lock(); }
+ explicit operator bool() const noexcept
+ { return owns_lock(); }
mutex_type*
- mutex() const
+ mutex() const noexcept
{ return _M_device; }
private:
- unique_lock(unique_lock const&);
- unique_lock& operator=(unique_lock const&);
-
mutex_type* _M_device;
bool _M_owns; // XXX use atomic_bool
};
+ /// Partial specialization for unique_lock objects.
template<typename _Mutex>
- void
- swap(unique_lock<_Mutex>& __x, unique_lock<_Mutex>& __y);
+ inline void
+ swap(unique_lock<_Mutex>& __x, unique_lock<_Mutex>& __y) noexcept
+ { __x.swap(__y); }
- template<typename _Mutex>
- void
- swap(unique_lock<_Mutex>&& __x, unique_lock<_Mutex>& __y);
+ template<int _Idx>
+ struct __unlock_impl
+ {
+ template<typename... _Lock>
+ static void
+ __do_unlock(tuple<_Lock&...>& __locks)
+ {
+ std::get<_Idx>(__locks).unlock();
+ __unlock_impl<_Idx - 1>::__do_unlock(__locks);
+ }
+ };
- template<typename _Mutex>
- void
- swap(unique_lock<_Mutex>& __x, unique_lock<_Mutex>&& __y);
+ template<>
+ struct __unlock_impl<-1>
+ {
+ template<typename... _Lock>
+ static void
+ __do_unlock(tuple<_Lock&...>&)
+ { }
+ };
- template<typename _L1, typename _L2, typename ..._L3>
+ template<typename _Lock>
+ unique_lock<_Lock>
+ __try_to_lock(_Lock& __l)
+ { return unique_lock<_Lock>(__l, try_to_lock); }
+
+ template<int _Idx, bool _Continue = true>
+ struct __try_lock_impl
+ {
+ template<typename... _Lock>
+ static void
+ __do_try_lock(tuple<_Lock&...>& __locks, int& __idx)
+ {
+ __idx = _Idx;
+ auto __lock = __try_to_lock(std::get<_Idx>(__locks));
+ if (__lock.owns_lock())
+ {
+ __try_lock_impl<_Idx + 1, _Idx + 2 < sizeof...(_Lock)>::
+ __do_try_lock(__locks, __idx);
+ if (__idx == -1)
+ __lock.release();
+ }
+ }
+ };
+
+ template<int _Idx>
+ struct __try_lock_impl<_Idx, false>
+ {
+ template<typename... _Lock>
+ static void
+ __do_try_lock(tuple<_Lock&...>& __locks, int& __idx)
+ {
+ __idx = _Idx;
+ auto __lock = __try_to_lock(std::get<_Idx>(__locks));
+ if (__lock.owns_lock())
+ {
+ __idx = -1;
+ __lock.release();
+ }
+ }
+ };
+
+ /** @brief Generic try_lock.
+ * @param __l1 Meets Mutex requirements (try_lock() may throw).
+ * @param __l2 Meets Mutex requirements (try_lock() may throw).
+ * @param __l3 Meets Mutex requirements (try_lock() may throw).
+ * @return Returns -1 if all try_lock() calls return true. Otherwise returns
+ * a 0-based index corresponding to the argument that returned false.
+ * @post Either all arguments are locked, or none will be.
+ *
+ * Sequentially calls try_lock() on each argument.
+ */
+ template<typename _Lock1, typename _Lock2, typename... _Lock3>
int
- try_lock(_L1&, _L2&, _L3&...);
+ try_lock(_Lock1& __l1, _Lock2& __l2, _Lock3&... __l3)
+ {
+ int __idx;
+ auto __locks = std::tie(__l1, __l2, __l3...);
+ __try
+ { __try_lock_impl<0>::__do_try_lock(__locks, __idx); }
+ __catch(...)
+ { }
+ return __idx;
+ }
+ /** @brief Generic lock.
+ * @param __l1 Meets Mutex requirements (try_lock() may throw).
+ * @param __l2 Meets Mutex requirements (try_lock() may throw).
+ * @param __l3 Meets Mutex requirements (try_lock() may throw).
+ * @throw An exception thrown by an argument's lock() or try_lock() member.
+ * @post All arguments are locked.
+ *
+ * All arguments are locked via a sequence of calls to lock(), try_lock()
+ * and unlock(). If the call exits via an exception any locks that were
+ * obtained will be released.
+ */
template<typename _L1, typename _L2, typename ..._L3>
void
- lock(_L1&, _L2&, _L3&...);
+ lock(_L1& __l1, _L2& __l2, _L3&... __l3)
+ {
+ while (true)
+ {
+ unique_lock<_L1> __first(__l1);
+ int __idx;
+ auto __locks = std::tie(__l2, __l3...);
+ __try_lock_impl<0, sizeof...(_L3)>::__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;
- once_flag()
+ 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)();
+
+ template<typename _Callable>
+ inline void
+ __once_call_impl()
{
- __native_type __tmp = __GTHREAD_ONCE_INIT;
- _M_once = __tmp;
+ (*(_Callable*)__once_callable)();
}
+#else
+ extern function<void()> __once_functor;
- __native_type&
- _M_get() { return _M_once; }
+ extern void
+ __set_once_functor_lock_ptr(unique_lock<mutex>*);
- private:
- __native_type _M_once;
- once_flag(const once_flag&);
- once_flag& operator=(const once_flag&);
- };
+ 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)
+ call_once(once_flag& __once, _Callable&& __f, _Args&&... __args)
{
- int __e = __gthread_once(&(__once._M_get()), __f(__args...));
+#ifdef _GLIBCXX_HAVE_TLS
+ auto __bound_functor = std::__bind_simple(std::forward<_Callable>(__f),
+ std::forward<_Args>(__args)...);
+ __once_callable = &__bound_functor;
+ __once_call = &__once_call_impl<decltype(__bound_functor)>;
+#else
+ unique_lock<mutex> __functor_lock(__get_once_mutex());
+ auto __callable = std::__bind_simple(std::forward<_Callable>(__f),
+ std::forward<_Args>(__args)...);
+ __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
+#endif // _GLIBCXX_USE_C99_STDINT_TR1
+
+#endif // __GXX_EXPERIMENTAL_CXX0X__
+
+#endif // _GLIBCXX_MUTEX
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