// <mutex> -*- C++ -*-
-// Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009
+// Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
// 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>
+# include <bits/c++0x_warning.h>
#else
#include <tuple>
-#include <cstddef>
#include <chrono>
#include <exception>
#include <type_traits>
#if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
-namespace std
+namespace std _GLIBCXX_VISIBILITY(default)
{
- /// mutex
- class mutex
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+ // 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()
- {
- // XXX EAGAIN, ENOMEM, EPERM, EBUSY(may), EINVAL(may)
#ifdef __GTHREAD_MUTEX_INIT
- __gthread_mutex_t __tmp = __GTHREAD_MUTEX_INIT;
- _M_mutex = __tmp;
+ __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
+
+ __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;
}
bool
- try_lock()
+ try_lock() noexcept
{
// XXX EINVAL, EAGAIN, EBUSY
return !__gthread_mutex_trylock(&_M_mutex);
native_handle_type
native_handle()
{ return &_M_mutex; }
-
- private:
- __gthread_mutex_t _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()
- {
- // XXX EAGAIN, ENOMEM, EPERM, EBUSY(may), EINVAL(may)
-#ifdef __GTHREAD_RECURSIVE_MUTEX_INIT
- __gthread_recursive_mutex_t __tmp = __GTHREAD_RECURSIVE_MUTEX_INIT;
- _M_mutex = __tmp;
-#else
- __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION(&_M_mutex);
-#endif
- }
+ recursive_mutex() = default;
+ ~recursive_mutex() = default;
recursive_mutex(const recursive_mutex&) = delete;
recursive_mutex& operator=(const recursive_mutex&) = delete;
}
bool
- try_lock()
+ try_lock() noexcept
{
// XXX EINVAL, EAGAIN, EBUSY
return !__gthread_recursive_mutex_trylock(&_M_mutex);
native_handle_type
native_handle()
{ return &_M_mutex; }
-
- private:
- __gthread_recursive_mutex_t _M_mutex;
};
+#if _GTHREAD_USE_MUTEX_TIMEDLOCK
/// timed_mutex
- class timed_mutex
- {
- public:
- typedef __gthread_mutex_t* native_handle_type;
-
- timed_mutex()
- {
-#ifdef __GTHREAD_MUTEX_INIT
- __gthread_mutex_t __tmp = __GTHREAD_MUTEX_INIT;
- _M_mutex = __tmp;
+ class timed_mutex : private __mutex_base
+ {
+#ifdef _GLIBCXX_USE_CLOCK_MONOTONIC
+ typedef chrono::steady_clock __clock_t;
#else
- __GTHREAD_MUTEX_INIT_FUNCTION(&_M_mutex);
+ typedef chrono::high_resolution_clock __clock_t;
#endif
- }
+
+ 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;
}
bool
- try_lock()
+ try_lock() noexcept
{
// XXX EINVAL, EAGAIN, EBUSY
return !__gthread_mutex_trylock(&_M_mutex);
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::time_point_cast<chrono::seconds>(__atime);
chrono::nanoseconds __ns =
- chrono::duration_cast<chrono::nanoseconds>(__atime - __s);
+ 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())
- };
+ __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);
+ return !__gthread_mutex_timedlock(&_M_mutex, &__ts);
}
void
native_handle_type
native_handle()
{ return &_M_mutex; }
-
- private:
- __gthread_mutex_t _M_mutex;
-
-#ifdef _GLIBCXX_USE_CLOCK_MONOTONIC
- typedef chrono::monotonic_clock __clock_t;
-#else
- typedef chrono::high_resolution_clock __clock_t;
-#endif
+ private:
template<typename _Rep, typename _Period>
typename enable_if<
- ratio_less_equal<__clock_t::period, _Period>::value, bool>::type
+ 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);
+ __clock_t::time_point __atime = __clock_t::now()
+ + chrono::duration_cast<__clock_t::duration>(__rtime);
- return try_lock_until(__atime);
+ return try_lock_until(__atime);
}
template <typename _Rep, typename _Period>
typename enable_if<
- !ratio_less_equal<__clock_t::period, _Period>::value, bool>::type
+ !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()
+ __clock_t::time_point __atime = __clock_t::now()
+ ++chrono::duration_cast<__clock_t::duration>(__rtime);
- return try_lock_until(__atime);
+ return try_lock_until(__atime);
}
};
/// recursive_timed_mutex
- class recursive_timed_mutex
+ class recursive_timed_mutex : private __recursive_mutex_base
{
- public:
- typedef __gthread_recursive_mutex_t* native_handle_type;
-
- recursive_timed_mutex()
- {
- // XXX EAGAIN, ENOMEM, EPERM, EBUSY(may), EINVAL(may)
-#ifdef __GTHREAD_RECURSIVE_MUTEX_INIT
- __gthread_recursive_mutex_t __tmp = __GTHREAD_RECURSIVE_MUTEX_INIT;
- _M_mutex = __tmp;
+#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
- }
+
+ 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;
}
bool
- try_lock()
+ try_lock() noexcept
{
// XXX EINVAL, EAGAIN, EBUSY
return !__gthread_recursive_mutex_trylock(&_M_mutex);
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::time_point_cast<chrono::seconds>(__atime);
chrono::nanoseconds __ns =
- chrono::duration_cast<chrono::nanoseconds>(__atime - __s);
+ 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())
- };
+ __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);
+ return !__gthread_recursive_mutex_timedlock(&_M_mutex, &__ts);
}
void
{ return &_M_mutex; }
private:
- __gthread_recursive_mutex_t _M_mutex;
-
-#ifdef _GLIBCXX_USE_CLOCK_MONOTONIC
- typedef chrono::monotonic_clock __clock_t;
-#else
- typedef chrono::high_resolution_clock __clock_t;
-#endif
-
template<typename _Rep, typename _Period>
typename enable_if<
- ratio_less_equal<__clock_t::period, _Period>::value, bool>::type
+ 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);
+ __clock_t::time_point __atime = __clock_t::now()
+ + chrono::duration_cast<__clock_t::duration>(__rtime);
- return try_lock_until(__atime);
+ return try_lock_until(__atime);
}
template <typename _Rep, typename _Period>
typename enable_if<
- !ratio_less_equal<__clock_t::period, _Period>::value, bool>::type
+ !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()
+ __clock_t::time_point __atime = __clock_t::now()
+ ++chrono::duration_cast<__clock_t::duration>(__rtime);
- return try_lock_until(__atime);
+ return try_lock_until(__atime);
}
};
+#endif
/// 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(); }
{
public:
typedef _Mutex mutex_type;
-
- unique_lock()
+
+ unique_lock() noexcept
: _M_device(0), _M_owns(false)
{ }
_M_owns = true;
}
- unique_lock(mutex_type& __m, defer_lock_t)
+ unique_lock(mutex_type& __m, defer_lock_t) noexcept
: _M_device(&__m), _M_owns(false)
{ }
}
template<typename _Clock, typename _Duration>
- unique_lock(mutex_type& __m,
+ 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 _Rep, typename _Period>
- unique_lock(mutex_type& __m,
+ unique_lock(mutex_type& __m,
const chrono::duration<_Rep, _Period>& __rtime)
: _M_device(&__m), _M_owns(_M_device->try_lock_for(__rtime))
{ }
unique_lock(const unique_lock&) = delete;
unique_lock& operator=(const unique_lock&) = delete;
- unique_lock(unique_lock&& __u)
+ 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)
+ unique_lock& operator=(unique_lock&& __u) noexcept
{
- if(_M_owns)
+ if(_M_owns)
unlock();
-
+
unique_lock(std::move(__u)).swap(*this);
__u._M_device = 0;
__u._M_owns = false;
-
+
return *this;
}
lock()
{
if (!_M_device)
- __throw_system_error((int)errc::operation_not_permitted);
+ __throw_system_error(int(errc::operation_not_permitted));
else if (_M_owns)
- __throw_system_error((int)errc::resource_deadlock_would_occur);
+ __throw_system_error(int(errc::resource_deadlock_would_occur));
else
{
_M_device->lock();
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_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();
+ _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)
- {
+ bool
+ try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime)
+ {
if (!_M_device)
- __throw_system_error((int)errc::operation_not_permitted);
+ __throw_system_error(int(errc::operation_not_permitted));
else if (_M_owns)
- __throw_system_error((int)errc::resource_deadlock_would_occur);
+ __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);
+ __throw_system_error(int(errc::operation_not_permitted));
else if (_M_owns)
- __throw_system_error((int)errc::resource_deadlock_would_occur);
+ __throw_system_error(int(errc::resource_deadlock_would_occur));
else
{
_M_owns = _M_device->try_lock_for(__rtime);
void
unlock()
{
- if (!_M_owns)
- __throw_system_error((int)errc::operation_not_permitted);
- else if (_M_device)
- {
- _M_device->unlock();
- _M_owns = false;
- }
+ if (!_M_owns)
+ __throw_system_error(int(errc::operation_not_permitted));
+ else if (_M_device)
+ {
+ _M_device->unlock();
+ _M_owns = false;
+ }
}
-
+
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 = 0;
}
bool
- owns_lock() const
+ owns_lock() const noexcept
{ return _M_owns; }
- /* explicit */ operator bool () const
+ explicit operator bool() const noexcept
{ return owns_lock(); }
mutex_type*
- mutex() const
+ mutex() const noexcept
{ return _M_device; }
private:
bool _M_owns; // XXX use atomic_bool
};
+ /// Partial specialization for unique_lock objects.
template<typename _Mutex>
inline void
- swap(unique_lock<_Mutex>& __x, unique_lock<_Mutex>& __y)
- { __x.swap(__y); }
-
- template<typename _Mutex>
- inline void
- swap(unique_lock<_Mutex>&& __x, unique_lock<_Mutex>& __y)
- { __x.swap(__y); }
-
- template<typename _Mutex>
- inline void
- swap(unique_lock<_Mutex>& __x, unique_lock<_Mutex>&& __y)
+ swap(unique_lock<_Mutex>& __x, unique_lock<_Mutex>& __y) noexcept
{ __x.swap(__y); }
template<int _Idx>
struct __unlock_impl
{
template<typename... _Lock>
- static void
- __do_unlock(tuple<_Lock&...>& __locks)
- {
+ static void
+ __do_unlock(tuple<_Lock&...>& __locks)
+ {
std::get<_Idx>(__locks).unlock();
__unlock_impl<_Idx - 1>::__do_unlock(__locks);
}
};
-
+
template<>
struct __unlock_impl<-1>
{
template<typename... _Lock>
- static void
- __do_unlock(tuple<_Lock&...>&)
- { }
+ static void
+ __do_unlock(tuple<_Lock&...>&)
+ { }
};
+ 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 int
- __do_try_lock(tuple<_Lock&...>& __locks)
- {
- if(std::get<_Idx>(__locks).try_lock())
- {
- return __try_lock_impl<_Idx + 1,
- _Idx + 2 < sizeof...(_Lock)>::__do_try_lock(__locks);
- }
- else
- {
- __unlock_impl<_Idx>::__do_unlock(__locks);
- return _Idx;
- }
+ 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 int
- __do_try_lock(tuple<_Lock&...>& __locks)
- {
- if(std::get<_Idx>(__locks).try_lock())
- return -1;
- else
- {
- __unlock_impl<_Idx>::__do_unlock(__locks);
- return _Idx;
- }
+ 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
+ * @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.
*
int
try_lock(_Lock1& __l1, _Lock2& __l2, _Lock3&... __l3)
{
- tuple<_Lock1&, _Lock2&, _Lock3&...> __locks(__l1, __l2, __l3...);
- return __try_lock_impl<0>::__do_try_lock(__locks);
+ 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;
+ }
+ }
+ }
/// once_flag
struct once_flag
{
+ private:
typedef __gthread_once_t __native_type;
+ __native_type _M_once = __GTHREAD_ONCE_INIT;
- once_flag()
- {
- __gthread_once_t __tmp = __GTHREAD_ONCE_INIT;
- _M_once = __tmp;
- }
-
+ 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);
-
- private:
- __native_type _M_once;
+ call_once(once_flag& __once, _Callable&& __f, _Args&&... __args);
};
#ifdef _GLIBCXX_HAVE_TLS
extern __thread void (*__once_call)();
template<typename _Callable>
- inline void
+ inline void
__once_call_impl()
{
(*(_Callable*)__once_callable)();
#else
extern function<void()> __once_functor;
- extern unique_lock<mutex>&
- __get_once_functor_lock();
+ extern void
+ __set_once_functor_lock_ptr(unique_lock<mutex>*);
+
+ extern mutex&
+ __get_once_mutex();
#endif
- extern "C" void __once_proxy();
+ 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)
{
#ifdef _GLIBCXX_HAVE_TLS
- auto __bound_functor = bind(__f, __args...);
+ 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_functor_lock();
- __functor_lock.lock();
- __once_functor = bind(__f, __args...);
+ 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
+#ifndef _GLIBCXX_HAVE_TLS
if (__functor_lock)
- __functor_lock.unlock();
+ __set_once_functor_lock_ptr(0);
#endif
if (__e)
__throw_system_error(__e);
}
-}
+
+ // @} group mutexes
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace
#endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1
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