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// -*- C++ -*- header.

// Copyright (C) 2008-2012 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

// <http://www.gnu.org/licenses/>.

/** @file bits/atomic_base.h

 *  This is an internal header file, included by other library headers.

 *  Do not attempt to use it directly. @headername{atomic}

 */

#ifndef _GLIBCXX_ATOMIC_BASE_H

#define _GLIBCXX_ATOMIC_BASE_H 1

#pragma GCC system_header

#include <bits/c++config.h>

#include <stdbool.h>

#include <stdint.h>

#include <bits/atomic_lockfree_defines.h>

namespace std _GLIBCXX_VISIBILITY(default)

{

_GLIBCXX_BEGIN_NAMESPACE_VERSION

  /**

   * @defgroup atomics Atomics

   *

   * Components for performing atomic operations.

   * @{

   */

  /// Enumeration for memory_order

  typedef enum memory_order

    {

      memory_order_relaxed,

      memory_order_consume,

      memory_order_acquire,

      memory_order_release,

      memory_order_acq_rel,

      memory_order_seq_cst

    } memory_order;

  // Drop release ordering as per [atomics.types.operations.req]/21

  constexpr memory_order

  __cmpexch_failure_order(memory_order __m) noexcept

  {

    return __m == memory_order_acq_rel ? memory_order_acquire

      : __m == memory_order_release ? memory_order_relaxed : __m;

  }

  inline void

  atomic_thread_fence(memory_order __m) noexcept

  { __atomic_thread_fence(__m); }

  inline void

  atomic_signal_fence(memory_order __m) noexcept

  { __atomic_signal_fence(__m); }

  /// kill_dependency

  template<typename _Tp>

    inline _Tp

    kill_dependency(_Tp __y) noexcept

    {

      _Tp __ret(__y);

      return __ret;

    }

  // Base types for atomics.

  template<typename _IntTp>

    struct __atomic_base;

  /// atomic_char

  typedef __atomic_base<char>                   atomic_char;

  /// atomic_schar

  typedef __atomic_base<signed char>            atomic_schar;

  /// atomic_uchar

  typedef __atomic_base<unsigned char>          atomic_uchar;

  /// atomic_short

  typedef __atomic_base<short>                  atomic_short;

  /// atomic_ushort

  typedef __atomic_base<unsigned short>         atomic_ushort;

  /// atomic_int

  typedef __atomic_base<int>                    atomic_int;

  /// atomic_uint

  typedef __atomic_base<unsigned int>           atomic_uint;

  /// atomic_long

  typedef __atomic_base<long>                   atomic_long;

  /// atomic_ulong

  typedef __atomic_base<unsigned long>          atomic_ulong;

  /// atomic_llong

  typedef __atomic_base<long long>              atomic_llong;

  /// atomic_ullong

  typedef __atomic_base<unsigned long long>     atomic_ullong;

  /// atomic_wchar_t

  typedef __atomic_base<wchar_t>                atomic_wchar_t;

  /// atomic_char16_t

  typedef __atomic_base<char16_t>               atomic_char16_t;

  /// atomic_char32_t

  typedef __atomic_base<char32_t>               atomic_char32_t;

  /// atomic_char32_t

  typedef __atomic_base<char32_t>               atomic_char32_t;

  /// atomic_int_least8_t

  typedef __atomic_base<int_least8_t>           atomic_int_least8_t;

  /// atomic_uint_least8_t

  typedef __atomic_base<uint_least8_t>          atomic_uint_least8_t;

  /// atomic_int_least16_t

  typedef __atomic_base<int_least16_t>          atomic_int_least16_t;

  /// atomic_uint_least16_t

  typedef __atomic_base<uint_least16_t>         atomic_uint_least16_t;

  /// atomic_int_least32_t

  typedef __atomic_base<int_least32_t>          atomic_int_least32_t;

  /// atomic_uint_least32_t

  typedef __atomic_base<uint_least32_t>         atomic_uint_least32_t;

  /// atomic_int_least64_t

  typedef __atomic_base<int_least64_t>          atomic_int_least64_t;

  /// atomic_uint_least64_t

  typedef __atomic_base<uint_least64_t>         atomic_uint_least64_t;

  /// atomic_int_fast8_t

  typedef __atomic_base<int_fast8_t>            atomic_int_fast8_t;

  /// atomic_uint_fast8_t

  typedef __atomic_base<uint_fast8_t>           atomic_uint_fast8_t;

  /// atomic_int_fast16_t

  typedef __atomic_base<int_fast16_t>           atomic_int_fast16_t;

  /// atomic_uint_fast16_t

  typedef __atomic_base<uint_fast16_t>          atomic_uint_fast16_t;

  /// atomic_int_fast32_t

  typedef __atomic_base<int_fast32_t>           atomic_int_fast32_t;

  /// atomic_uint_fast32_t

  typedef __atomic_base<uint_fast32_t>          atomic_uint_fast32_t;

  /// atomic_int_fast64_t

  typedef __atomic_base<int_fast64_t>           atomic_int_fast64_t;

  /// atomic_uint_fast64_t

  typedef __atomic_base<uint_fast64_t>          atomic_uint_fast64_t;

  /// atomic_intptr_t

  typedef __atomic_base<intptr_t>               atomic_intptr_t;

  /// atomic_uintptr_t

  typedef __atomic_base<uintptr_t>              atomic_uintptr_t;

  /// atomic_size_t

  typedef __atomic_base<size_t>                 atomic_size_t;

  /// atomic_intmax_t

  typedef __atomic_base<intmax_t>               atomic_intmax_t;

  /// atomic_uintmax_t

  typedef __atomic_base<uintmax_t>              atomic_uintmax_t;

  /// atomic_ptrdiff_t

  typedef __atomic_base<ptrdiff_t>              atomic_ptrdiff_t;

#define ATOMIC_VAR_INIT(_VI) { _VI }

  template<typename _Tp>

    struct atomic;

  template<typename _Tp>

    struct atomic<_Tp*>;

  /**

   *  @brief Base type for atomic_flag.

   *

   *  Base type is POD with data, allowing atomic_flag to derive from

   *  it and meet the standard layout type requirement. In addition to

   *  compatibilty with a C interface, this allows different

   *  implementations of atomic_flag to use the same atomic operation

   *  functions, via a standard conversion to the __atomic_flag_base

   *  argument.

  */

  _GLIBCXX_BEGIN_EXTERN_C

  struct __atomic_flag_base

  {

    /* The target's "set" value for test-and-set may not be exactly 1.  */

#if __GCC_ATOMIC_TEST_AND_SET_TRUEVAL == 1

    bool _M_i;

#else

    unsigned char _M_i;

#endif

  };

  _GLIBCXX_END_EXTERN_C

#define ATOMIC_FLAG_INIT { 0 }

  /// atomic_flag

  struct atomic_flag : public __atomic_flag_base

  {

    atomic_flag() noexcept = default;

    ~atomic_flag() noexcept = default;

    atomic_flag(const atomic_flag&) = delete;

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

    atomic_flag& operator=(const atomic_flag&) volatile = delete;

    // Conversion to ATOMIC_FLAG_INIT.

    constexpr atomic_flag(bool __i) noexcept

      : __atomic_flag_base({ __i ? __GCC_ATOMIC_TEST_AND_SET_TRUEVAL : 0 })

    { }

    bool

    test_and_set(memory_order __m = memory_order_seq_cst) noexcept

    {

      return __atomic_test_and_set (&_M_i, __m);

    }

    bool

    test_and_set(memory_order __m = memory_order_seq_cst) volatile noexcept

    {

      return __atomic_test_and_set (&_M_i, __m);

    }

    void

    clear(memory_order __m = memory_order_seq_cst) noexcept

    {

      __glibcxx_assert(__m != memory_order_consume);

      __glibcxx_assert(__m != memory_order_acquire);

      __glibcxx_assert(__m != memory_order_acq_rel);

      __atomic_clear (&_M_i, __m);

    }

    void

    clear(memory_order __m = memory_order_seq_cst) volatile noexcept

    {

      __glibcxx_assert(__m != memory_order_consume);

      __glibcxx_assert(__m != memory_order_acquire);

      __glibcxx_assert(__m != memory_order_acq_rel);

      __atomic_clear (&_M_i, __m);

    }

  };

  /// Base class for atomic integrals.

  //

  // For each of the integral types, define atomic_[integral type] struct

  //

  // atomic_bool     bool

  // atomic_char     char

  // atomic_schar    signed char

  // atomic_uchar    unsigned char

  // atomic_short    short

  // atomic_ushort   unsigned short

  // atomic_int      int

  // atomic_uint     unsigned int

  // atomic_long     long

  // atomic_ulong    unsigned long

  // atomic_llong    long long

  // atomic_ullong   unsigned long long

  // atomic_char16_t char16_t

  // atomic_char32_t char32_t

  // atomic_wchar_t  wchar_t

  //

  // NB: Assuming _ITp is an integral scalar type that is 1, 2, 4, or

  // 8 bytes, since that is what GCC built-in functions for atomic

  // memory access expect.

  template<typename _ITp>

    struct __atomic_base

    {

    private:

      typedef _ITp      __int_type;

      __int_type        _M_i;

    public:

      __atomic_base() noexcept = default;

      ~__atomic_base() noexcept = default;

      __atomic_base(const __atomic_base&) = delete;

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

      __atomic_base& operator=(const __atomic_base&) volatile = delete;

      // Requires __int_type convertible to _M_i.

      constexpr __atomic_base(__int_type __i) noexcept : _M_i (__i) { }

      operator __int_type() const noexcept

      { return load(); }

      operator __int_type() const volatile noexcept

      { return load(); }

      __int_type

      operator=(__int_type __i) noexcept

      {

        store(__i);

        return __i;

      }

      __int_type

      operator=(__int_type __i) volatile noexcept

      {

        store(__i);

        return __i;

      }

      __int_type

      operator++(int) noexcept

      { return fetch_add(1); }

      __int_type

      operator++(int) volatile noexcept

      { return fetch_add(1); }

      __int_type

      operator--(int) noexcept

      { return fetch_sub(1); }

      __int_type

      operator--(int) volatile noexcept

      { return fetch_sub(1); }

      __int_type

      operator++() noexcept

      { return __atomic_add_fetch(&_M_i, 1, memory_order_seq_cst); }

      __int_type

      operator++() volatile noexcept

      { return __atomic_add_fetch(&_M_i, 1, memory_order_seq_cst); }

      __int_type

      operator--() noexcept

      { return __atomic_sub_fetch(&_M_i, 1, memory_order_seq_cst); }

      __int_type

      operator--() volatile noexcept

      { return __atomic_sub_fetch(&_M_i, 1, memory_order_seq_cst); }

      __int_type

      operator+=(__int_type __i) noexcept

      { return __atomic_add_fetch(&_M_i, __i, memory_order_seq_cst); }

      __int_type

      operator+=(__int_type __i) volatile noexcept

      { return __atomic_add_fetch(&_M_i, __i, memory_order_seq_cst); }

      __int_type

      operator-=(__int_type __i) noexcept

      { return __atomic_sub_fetch(&_M_i, __i, memory_order_seq_cst); }

      __int_type

      operator-=(__int_type __i) volatile noexcept

      { return __atomic_sub_fetch(&_M_i, __i, memory_order_seq_cst); }

      __int_type

      operator&=(__int_type __i) noexcept

      { return __atomic_and_fetch(&_M_i, __i, memory_order_seq_cst); }

      __int_type

      operator&=(__int_type __i) volatile noexcept

      { return __atomic_and_fetch(&_M_i, __i, memory_order_seq_cst); }

      __int_type

      operator|=(__int_type __i) noexcept

      { return __atomic_or_fetch(&_M_i, __i, memory_order_seq_cst); }

      __int_type

      operator|=(__int_type __i) volatile noexcept

      { return __atomic_or_fetch(&_M_i, __i, memory_order_seq_cst); }

      __int_type

      operator^=(__int_type __i) noexcept

      { return __atomic_xor_fetch(&_M_i, __i, memory_order_seq_cst); }

      __int_type

      operator^=(__int_type __i) volatile noexcept

      { return __atomic_xor_fetch(&_M_i, __i, memory_order_seq_cst); }

      bool

      is_lock_free() const noexcept

      { return __atomic_is_lock_free(sizeof(_M_i), nullptr); }

      bool

      is_lock_free() const volatile noexcept

      { return __atomic_is_lock_free(sizeof(_M_i), nullptr); }

      void

      store(__int_type __i, memory_order __m = memory_order_seq_cst) noexcept

      {

        __glibcxx_assert(__m != memory_order_acquire);

        __glibcxx_assert(__m != memory_order_acq_rel);

        __glibcxx_assert(__m != memory_order_consume);

        __atomic_store_n(&_M_i, __i, __m);

      }

      void

      store(__int_type __i,

            memory_order __m = memory_order_seq_cst) volatile noexcept

      {

        __glibcxx_assert(__m != memory_order_acquire);

        __glibcxx_assert(__m != memory_order_acq_rel);

        __glibcxx_assert(__m != memory_order_consume);

        __atomic_store_n(&_M_i, __i, __m);

      }

      __int_type

      load(memory_order __m = memory_order_seq_cst) const noexcept

      {

        __glibcxx_assert(__m != memory_order_release);

        __glibcxx_assert(__m != memory_order_acq_rel);

        return __atomic_load_n(&_M_i, __m);

      }

      __int_type

      load(memory_order __m = memory_order_seq_cst) const volatile noexcept

      {

        __glibcxx_assert(__m != memory_order_release);

        __glibcxx_assert(__m != memory_order_acq_rel);

        return __atomic_load_n(&_M_i, __m);

      }

      __int_type

      exchange(__int_type __i,

               memory_order __m = memory_order_seq_cst) noexcept

      {

        return __atomic_exchange_n(&_M_i, __i, __m);

      }

      __int_type

      exchange(__int_type __i,

               memory_order __m = memory_order_seq_cst) volatile noexcept

      {

        return __atomic_exchange_n(&_M_i, __i, __m);

      }

      bool

      compare_exchange_weak(__int_type& __i1, __int_type __i2,

                            memory_order __m1, memory_order __m2) noexcept

      {

        __glibcxx_assert(__m2 != memory_order_release);

        __glibcxx_assert(__m2 != memory_order_acq_rel);

        __glibcxx_assert(__m2 <= __m1);

        return __atomic_compare_exchange_n(&_M_i, &__i1, __i2, 1, __m1, __m2);

      }

      bool

      compare_exchange_weak(__int_type& __i1, __int_type __i2,

                            memory_order __m1,

                            memory_order __m2) volatile noexcept

      {

        __glibcxx_assert(__m2 != memory_order_release);

        __glibcxx_assert(__m2 != memory_order_acq_rel);

        __glibcxx_assert(__m2 <= __m1);

        return __atomic_compare_exchange_n(&_M_i, &__i1, __i2, 1, __m1, __m2);

      }

      bool

      compare_exchange_weak(__int_type& __i1, __int_type __i2,

                            memory_order __m = memory_order_seq_cst) noexcept

      {

        return compare_exchange_weak(__i1, __i2, __m,

                                     __cmpexch_failure_order(__m));

      }

      bool

      compare_exchange_weak(__int_type& __i1, __int_type __i2,

                   memory_order __m = memory_order_seq_cst) volatile noexcept

      {

        return compare_exchange_weak(__i1, __i2, __m,

                                     __cmpexch_failure_order(__m));

      }

      bool

      compare_exchange_strong(__int_type& __i1, __int_type __i2,

                              memory_order __m1, memory_order __m2) noexcept

      {

        __glibcxx_assert(__m2 != memory_order_release);

        __glibcxx_assert(__m2 != memory_order_acq_rel);

        __glibcxx_assert(__m2 <= __m1);

        return __atomic_compare_exchange_n(&_M_i, &__i1, __i2, 0, __m1, __m2);

      }

      bool

      compare_exchange_strong(__int_type& __i1, __int_type __i2,

                              memory_order __m1,

                              memory_order __m2) volatile noexcept

      {

        __glibcxx_assert(__m2 != memory_order_release);

        __glibcxx_assert(__m2 != memory_order_acq_rel);

        __glibcxx_assert(__m2 <= __m1);

        return __atomic_compare_exchange_n(&_M_i, &__i1, __i2, 0, __m1, __m2);

      }

      bool

      compare_exchange_strong(__int_type& __i1, __int_type __i2,

                              memory_order __m = memory_order_seq_cst) noexcept

      {

        return compare_exchange_strong(__i1, __i2, __m,

                                       __cmpexch_failure_order(__m));

      }

      bool

      compare_exchange_strong(__int_type& __i1, __int_type __i2,

                 memory_order __m = memory_order_seq_cst) volatile noexcept

      {

        return compare_exchange_strong(__i1, __i2, __m,

                                       __cmpexch_failure_order(__m));

      }

      __int_type

      fetch_add(__int_type __i,

                memory_order __m = memory_order_seq_cst) noexcept

      { return __atomic_fetch_add(&_M_i, __i, __m); }

      __int_type

      fetch_add(__int_type __i,

                memory_order __m = memory_order_seq_cst) volatile noexcept

      { return __atomic_fetch_add(&_M_i, __i, __m); }

      __int_type

      fetch_sub(__int_type __i,

                memory_order __m = memory_order_seq_cst) noexcept

      { return __atomic_fetch_sub(&_M_i, __i, __m); }

      __int_type

      fetch_sub(__int_type __i,

                memory_order __m = memory_order_seq_cst) volatile noexcept

      { return __atomic_fetch_sub(&_M_i, __i, __m); }

      __int_type

      fetch_and(__int_type __i,

                memory_order __m = memory_order_seq_cst) noexcept

      { return __atomic_fetch_and(&_M_i, __i, __m); }

      __int_type

      fetch_and(__int_type __i,

                memory_order __m = memory_order_seq_cst) volatile noexcept

      { return __atomic_fetch_and(&_M_i, __i, __m); }

      __int_type

      fetch_or(__int_type __i,

               memory_order __m = memory_order_seq_cst) noexcept

      { return __atomic_fetch_or(&_M_i, __i, __m); }

      __int_type

      fetch_or(__int_type __i,

               memory_order __m = memory_order_seq_cst) volatile noexcept

      { return __atomic_fetch_or(&_M_i, __i, __m); }

      __int_type

      fetch_xor(__int_type __i,

                memory_order __m = memory_order_seq_cst) noexcept

      { return __atomic_fetch_xor(&_M_i, __i, __m); }

      __int_type

      fetch_xor(__int_type __i,

                memory_order __m = memory_order_seq_cst) volatile noexcept

      { return __atomic_fetch_xor(&_M_i, __i, __m); }

    };

  /// Partial specialization for pointer types.

  template<typename _PTp>

    struct __atomic_base<_PTp*>

    {

    private:

      typedef _PTp*     __pointer_type;

      __pointer_type    _M_p;

      // Factored out to facilitate explicit specialization.

      constexpr ptrdiff_t

      _M_type_size(ptrdiff_t __d) { return __d * sizeof(_PTp); }

      constexpr ptrdiff_t

      _M_type_size(ptrdiff_t __d) volatile { return __d * sizeof(_PTp); }

    public:

      __atomic_base() noexcept = default;

      ~__atomic_base() noexcept = default;

      __atomic_base(const __atomic_base&) = delete;

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

      __atomic_base& operator=(const __atomic_base&) volatile = delete;

      // Requires __pointer_type convertible to _M_p.

      constexpr __atomic_base(__pointer_type __p) noexcept : _M_p (__p) { }

      operator __pointer_type() const noexcept

      { return load(); }

      operator __pointer_type() const volatile noexcept

      { return load(); }

      __pointer_type

      operator=(__pointer_type __p) noexcept

      {

        store(__p);

        return __p;

      }

      __pointer_type

      operator=(__pointer_type __p) volatile noexcept

      {

        store(__p);

        return __p;

      }

      __pointer_type

      operator++(int) noexcept

      { return fetch_add(1); }

      __pointer_type

      operator++(int) volatile noexcept

      { return fetch_add(1); }

      __pointer_type

      operator--(int) noexcept

      { return fetch_sub(1); }

      __pointer_type

      operator--(int) volatile noexcept

      { return fetch_sub(1); }

      __pointer_type

      operator++() noexcept

      { return __atomic_add_fetch(&_M_p, _M_type_size(1),

                                  memory_order_seq_cst); }

      __pointer_type

      operator++() volatile noexcept

      { return __atomic_add_fetch(&_M_p, _M_type_size(1),

                                  memory_order_seq_cst); }

      __pointer_type

      operator--() noexcept

      { return __atomic_sub_fetch(&_M_p, _M_type_size(1),

                                  memory_order_seq_cst); }

      __pointer_type

      operator--() volatile noexcept

      { return __atomic_sub_fetch(&_M_p, _M_type_size(1),

                                  memory_order_seq_cst); }

      __pointer_type

      operator+=(ptrdiff_t __d) noexcept

      { return __atomic_add_fetch(&_M_p, _M_type_size(__d),

                                  memory_order_seq_cst); }

      __pointer_type

      operator+=(ptrdiff_t __d) volatile noexcept

      { return __atomic_add_fetch(&_M_p, _M_type_size(__d),

                                  memory_order_seq_cst); }

      __pointer_type

      operator-=(ptrdiff_t __d) noexcept

      { return __atomic_sub_fetch(&_M_p, _M_type_size(__d),

                                  memory_order_seq_cst); }

      __pointer_type

      operator-=(ptrdiff_t __d) volatile noexcept

      { return __atomic_sub_fetch(&_M_p, _M_type_size(__d),

                                  memory_order_seq_cst); }

      bool

      is_lock_free() const noexcept

      { return __atomic_is_lock_free(_M_type_size(1), nullptr); }