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//  -*- C++ -*-

// Copyright (C) 2003-2012 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

// .

/** @file include/mutex

 *  This is a Standard C++ Library header.

 */

#ifndef _GLIBCXX_MUTEX

#define _GLIBCXX_MUTEX 1

#pragma GCC system_header

#if __cplusplus < 201103L

# include 

#else

#include 

#include 

#include 

#include 

#include 

#include 

#include 

#include 

#include  // for std::swap

#if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)

namespace std _GLIBCXX_VISIBILITY(default)

{

_GLIBCXX_BEGIN_NAMESPACE_VERSION

  // Common base class for std::mutex and std::timed_mutex

  class __mutex_base

  {

  protected:

    typedef __gthread_mutex_t                   __native_type;

#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

    __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()

    { __gthread_recursive_mutex_destroy(&_M_mutex); }

#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);

    }

    bool

    try_lock() noexcept

    {

      // XXX EINVAL, EAGAIN, EBUSY

      return !__gthread_mutex_trylock(&_M_mutex);

    }

    void

    unlock()

    {

      // XXX EINVAL, EAGAIN, EPERM

      __gthread_mutex_unlock(&_M_mutex);

    }

    native_handle_type

    native_handle()

    { return &_M_mutex; }

  };

  /// recursive_mutex

  class recursive_mutex : private __recursive_mutex_base

  {

  public:

    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);

    }

    bool

    try_lock() noexcept

    {

      // 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

    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;

    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 

      bool

      try_lock_for(const chrono::duration<_Rep, _Period>& __rtime)

      { return __try_lock_for_impl(__rtime); }

    template 

      bool

      try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime)

      {

        chrono::time_point<_Clock, chrono::seconds> __s =

          chrono::time_point_cast(__atime);

        chrono::nanoseconds __ns =

          chrono::duration_cast(__atime - __s);

        __gthread_time_t __ts = {

          static_cast(__s.time_since_epoch().count()),

          static_cast(__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 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 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);

    }

    bool

    try_lock() noexcept

    {

      // XXX EINVAL, EAGAIN, EBUSY

      return !__gthread_recursive_mutex_trylock(&_M_mutex);

    }

    template 

      bool

      try_lock_for(const chrono::duration<_Rep, _Period>& __rtime)

      { return __try_lock_for_impl(__rtime); }

    template 

      bool

      try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime)

      {

        chrono::time_point<_Clock, chrono::seconds>  __s =

          chrono::time_point_cast(__atime);

        chrono::nanoseconds __ns =

          chrono::duration_cast(__atime - __s);

        __gthread_time_t __ts = {

          static_cast(__s.time_since_epoch().count()),

          static_cast(__ns.count())

        };

        return !__gthread_recursive_mutex_timedlock(&_M_mutex, &__ts);

      }

    void

    unlock()

    {

      // XXX EINVAL, EAGAIN, EBUSY

      __gthread_recursive_mutex_unlock(&_M_mutex);

    }

    native_handle_type

    native_handle()

    { return &_M_mutex; }

  private:

    template

      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 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);

      }

  };

#endif

  /// Do not acquire ownership of the mutex.

  struct defer_lock_t { };

  /// Try to acquire ownership of the mutex without blocking.

  struct try_to_lock_t { };

  /// Assume the calling thread has already obtained mutex ownership

  /// and manage it.

  struct adopt_lock_t { };

  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

  // the destructor call in accordance with RAII style.

  template

    class lock_guard

    {

    public:

      typedef _Mutex mutex_type;

      explicit lock_guard(mutex_type& __m) : _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;

    };

  /// unique_lock

  template

    class unique_lock

    {

    public:

      typedef _Mutex mutex_type;

      unique_lock() noexcept

      : _M_device(0), _M_owns(false)

      { }

      explicit unique_lock(mutex_type& __m)

      : _M_device(&__m), _M_owns(false)

      {

        lock();

        _M_owns = true;

      }

      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())

      { }

      unique_lock(mutex_type& __m, adopt_lock_t)

      : _M_device(&__m), _M_owns(true)

      {

        // XXX calling thread owns mutex

      }

      template

        unique_lock(mutex_type& __m,

                    const chrono::time_point<_Clock, _Duration>& __atime)

        : _M_device(&__m), _M_owns(_M_device->try_lock_until(__atime))

        { }

      template

        unique_lock(mutex_type& __m,

                    const chrono::duration<_Rep, _Period>& __rtime)

        : _M_device(&__m), _M_owns(_M_device->try_lock_for(__rtime))

        { }

      ~unique_lock()

      {

        if (_M_owns)

          unlock();

      }

      unique_lock(const unique_lock&) = delete;

      unique_lock& operator=(const unique_lock&) = delete;

      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)

          __throw_system_error(int(errc::operation_not_permitted));

        else if (_M_owns)

          __throw_system_error(int(errc::resource_deadlock_would_occur));

        else

          {

            _M_device->lock();

            _M_owns = true;

          }

      }

      bool

      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

          {

            _M_owns = _M_device->try_lock();

            return _M_owns;

          }

      }

      template

        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

        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_owns)

          __throw_system_error(int(errc::operation_not_permitted));

        else if (_M_device)

          {

            _M_device->unlock();

            _M_owns = false;

          }

      }

      void

      swap(unique_lock& __u) noexcept

      {

        std::swap(_M_device, __u._M_device);

        std::swap(_M_owns, __u._M_owns);

      }

      mutex_type*

      release() noexcept

      {

        mutex_type* __ret = _M_device;

        _M_device = 0;

        _M_owns = false;

        return __ret;

      }

      bool

      owns_lock() const noexcept

      { return _M_owns; }

      explicit operator bool() const noexcept

      { return owns_lock(); }

      mutex_type*

      mutex() const noexcept

      { return _M_device; }

    private:

      mutex_type*       _M_device;

      bool              _M_owns; // XXX use atomic_bool

    };

  /// Partial specialization for unique_lock objects.

  template

    inline void

    swap(unique_lock<_Mutex>& __x, unique_lock<_Mutex>& __y) noexcept

    { __x.swap(__y); }

  template

    struct __unlock_impl

    {

      template

        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

        static void

        __do_unlock(tuple<_Lock&...>&)

        { }

    };

  template

    unique_lock<_Lock>

    __try_to_lock(_Lock& __l)

    { return unique_lock<_Lock>(__l, try_to_lock); }

  template

    struct __try_lock_impl

    {

      template

        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

    struct __try_lock_impl<_Idx, false>

    {

      template

        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

    int

    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

    void

    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;

  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

      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

    inline void

    __once_call_impl()

    {

      (*(_Callable*)__once_callable)();

    }

#else

  extern function __once_functor;

  extern void

  __set_once_functor_lock_ptr(unique_lock*);

  extern mutex&

  __get_once_mutex();

#endif

  extern "C" void __once_proxy(void);

  /// call_once

  template

    void

    call_once(once_flag& __once, _Callable&& __f, _Args&&... __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;

#else

      unique_lock __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);

    }

  // @} group mutexes

_GLIBCXX_END_NAMESPACE_VERSION

} // namespace

#endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1

#endif // C++11

#endif // _GLIBCXX_MUTEX