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

// Copyright (C) 2008, 2009

// 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_2.h

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

 *  You should not attempt to use it directly.

 */

#ifndef _GLIBCXX_ATOMIC_2_H

#define _GLIBCXX_ATOMIC_2_H 1

#pragma GCC system_header

// _GLIBCXX_BEGIN_NAMESPACE(std)

// 2 == __atomic2 == Always lock-free

// Assumed:

// _GLIBCXX_ATOMIC_BUILTINS_1

// _GLIBCXX_ATOMIC_BUILTINS_2

// _GLIBCXX_ATOMIC_BUILTINS_4

// _GLIBCXX_ATOMIC_BUILTINS_8

namespace __atomic2

{

  /// atomic_flag

  struct atomic_flag : public __atomic_flag_base

  {

    atomic_flag() = default;

    ~atomic_flag() = default;

    atomic_flag(const atomic_flag&) = delete;

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

    // Conversion to ATOMIC_FLAG_INIT.

    atomic_flag(bool __i): __atomic_flag_base({ __i }) { }

    bool

    test_and_set(memory_order __m = memory_order_seq_cst)

    {

      // Redundant synchronize if built-in for lock is a full barrier.

      if (__m != memory_order_acquire && __m != memory_order_acq_rel)

        __sync_synchronize();

      return __sync_lock_test_and_set(&_M_i, 1);

    }

    void

    clear(memory_order __m = memory_order_seq_cst)

    {

      __glibcxx_assert(__m != memory_order_consume);

      __glibcxx_assert(__m != memory_order_acquire);

      __glibcxx_assert(__m != memory_order_acq_rel);

      __sync_lock_release(&_M_i);

      if (__m != memory_order_acquire && __m != memory_order_acq_rel)

        __sync_synchronize();

    }

  };

  /// 29.4.2, address types

  struct atomic_address

  {

  private:

    void* _M_i;

  public:

    atomic_address() = default;

    ~atomic_address() = default;

    atomic_address(const atomic_address&) = delete;

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

    atomic_address(void* __v) { _M_i = __v; }

    bool

    is_lock_free() const

    { return true; }

    void

    store(void* __v, memory_order __m = memory_order_seq_cst)

    {

      __glibcxx_assert(__m != memory_order_acquire);

      __glibcxx_assert(__m != memory_order_acq_rel);

      __glibcxx_assert(__m != memory_order_consume);

      if (__m == memory_order_relaxed)

        _M_i = __v;

      else

        {

          // write_mem_barrier();

          _M_i = __v;

          if (__m == memory_order_seq_cst)

            __sync_synchronize();

        }

    }

    void*

    load(memory_order __m = memory_order_seq_cst) const

    {

      __glibcxx_assert(__m != memory_order_release);

      __glibcxx_assert(__m != memory_order_acq_rel);

      __sync_synchronize();

      void* __ret = _M_i;

      __sync_synchronize();

      return __ret;

    }

    void*

    exchange(void* __v, memory_order __m = memory_order_seq_cst)

    {

      // XXX built-in assumes memory_order_acquire.

      return __sync_lock_test_and_set(&_M_i, __v);

    }

    bool

    compare_exchange_weak(void*& __v1, void* __v2, memory_order __m1,

                          memory_order __m2)

    { return compare_exchange_strong(__v1, __v2, __m1, __m2); }

    bool

    compare_exchange_weak(void*& __v1, void* __v2,

                          memory_order __m = memory_order_seq_cst)

    {

      return compare_exchange_weak(__v1, __v2, __m,

                                   __calculate_memory_order(__m));

    }

    bool

    compare_exchange_strong(void*& __v1, void* __v2, memory_order __m1,

                            memory_order __m2)

    {

      __glibcxx_assert(__m2 != memory_order_release);

      __glibcxx_assert(__m2 != memory_order_acq_rel);

      __glibcxx_assert(__m2 <= __m1);

      void* __v1o = __v1;

      void* __v1n = __sync_val_compare_and_swap(&_M_i, __v1o, __v2);

      // Assume extra stores (of same value) allowed in true case.

      __v1 = __v1n;

      return __v1o == __v1n;

    }

    bool

    compare_exchange_strong(void*& __v1, void* __v2,

                          memory_order __m = memory_order_seq_cst)

    {

      return compare_exchange_strong(__v1, __v2, __m,

                                     __calculate_memory_order(__m));

    }

    void*

    fetch_add(ptrdiff_t __d, memory_order __m = memory_order_seq_cst)

    { return __sync_fetch_and_add(&_M_i, __d); }

    void*

    fetch_sub(ptrdiff_t __d, memory_order __m = memory_order_seq_cst)

    { return __sync_fetch_and_sub(&_M_i, __d); }

    operator void*() const

    { return load(); }

    void*

    operator=(void* __v)

    {

      store(__v);

      return __v;

    }

    void*

    operator+=(ptrdiff_t __d)

    { return __sync_add_and_fetch(&_M_i, __d); }

    void*

    operator-=(ptrdiff_t __d)

    { return __sync_sub_and_fetch(&_M_i, __d); }

  };

  // 29.3.1 atomic integral types

  // 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

  // Base type.

  // 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 work on.

  template<typename _ITp>

    struct __atomic_base

    {

    private:

      typedef _ITp      __integral_type;

      __integral_type   _M_i;

    public:

      __atomic_base() = default;

      ~__atomic_base() = default;

      __atomic_base(const __atomic_base&) = delete;

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

      // Requires __integral_type convertible to _M_base._M_i.

      __atomic_base(__integral_type __i) { _M_i = __i; }

      operator __integral_type() const

      { return load(); }

      __integral_type

      operator=(__integral_type __i)

      {

        store(__i);

        return __i;

      }

      __integral_type

      operator++(int)

      { return fetch_add(1); }

      __integral_type

      operator--(int)

      { return fetch_sub(1); }

      __integral_type

      operator++()

      { return __sync_add_and_fetch(&_M_i, 1); }

      __integral_type

      operator--()

      { return __sync_sub_and_fetch(&_M_i, 1); }

      __integral_type

      operator+=(__integral_type __i)

      { return __sync_add_and_fetch(&_M_i, __i); }

      __integral_type

      operator-=(__integral_type __i)

      { return __sync_sub_and_fetch(&_M_i, __i); }

      __integral_type

      operator&=(__integral_type __i)

      { return __sync_and_and_fetch(&_M_i, __i); }

      __integral_type

      operator|=(__integral_type __i)

      { return __sync_or_and_fetch(&_M_i, __i); }

      __integral_type

      operator^=(__integral_type __i)

      { return __sync_xor_and_fetch(&_M_i, __i); }

      bool

      is_lock_free() const

      { return true; }

      void

      store(__integral_type __i, memory_order __m = memory_order_seq_cst)

      {

        __glibcxx_assert(__m != memory_order_acquire);

        __glibcxx_assert(__m != memory_order_acq_rel);

        __glibcxx_assert(__m != memory_order_consume);

        if (__m == memory_order_relaxed)

          _M_i = __i;

        else

          {

            // write_mem_barrier();

            _M_i = __i;

            if (__m == memory_order_seq_cst)

              __sync_synchronize();

          }

      }

      __integral_type

      load(memory_order __m = memory_order_seq_cst) const

      {

        __glibcxx_assert(__m != memory_order_release);

        __glibcxx_assert(__m != memory_order_acq_rel);

        __sync_synchronize();

        __integral_type __ret = _M_i;

        __sync_synchronize();

        return __ret;

      }

      __integral_type

      exchange(__integral_type __i, memory_order __m = memory_order_seq_cst)

      {

        // XXX built-in assumes memory_order_acquire.

        return __sync_lock_test_and_set(&_M_i, __i);

      }

      bool

      compare_exchange_weak(__integral_type& __i1, __integral_type __i2,

                            memory_order __m1, memory_order __m2)

      { return compare_exchange_strong(__i1, __i2, __m1, __m2); }

      bool

      compare_exchange_weak(__integral_type& __i1, __integral_type __i2,

                            memory_order __m = memory_order_seq_cst)

      {

        return compare_exchange_weak(__i1, __i2, __m,

                                     __calculate_memory_order(__m));

      }

      bool

      compare_exchange_strong(__integral_type& __i1, __integral_type __i2,

                              memory_order __m1, memory_order __m2)

      {

        __glibcxx_assert(__m2 != memory_order_release);

        __glibcxx_assert(__m2 != memory_order_acq_rel);

        __glibcxx_assert(__m2 <= __m1);

        __integral_type __i1o = __i1;

        __integral_type __i1n = __sync_val_compare_and_swap(&_M_i, __i1o, __i2);

        // Assume extra stores (of same value) allowed in true case.

        __i1 = __i1n;

        return __i1o == __i1n;

      }

      bool

      compare_exchange_strong(__integral_type& __i1, __integral_type __i2,

                              memory_order __m = memory_order_seq_cst)

      {

        return compare_exchange_strong(__i1, __i2, __m,

                                       __calculate_memory_order(__m));

      }

      __integral_type

      fetch_add(__integral_type __i,

                memory_order __m = memory_order_seq_cst)

      { return __sync_fetch_and_add(&_M_i, __i); }

      __integral_type

      fetch_sub(__integral_type __i,

                memory_order __m = memory_order_seq_cst)

      { return __sync_fetch_and_sub(&_M_i, __i); }

      __integral_type

      fetch_and(__integral_type __i,

                memory_order __m = memory_order_seq_cst)

      { return __sync_fetch_and_and(&_M_i, __i); }

      __integral_type

      fetch_or(__integral_type __i,

               memory_order __m = memory_order_seq_cst)

      { return __sync_fetch_and_or(&_M_i, __i); }

      __integral_type

      fetch_xor(__integral_type __i,

                memory_order __m = memory_order_seq_cst)

      { return __sync_fetch_and_xor(&_M_i, __i); }

    };

  /// atomic_bool

  // NB: No operators or fetch-operations for this type.

  struct atomic_bool

  {

  private:

    __atomic_base<bool> _M_base;

  public:

    atomic_bool() = default;

    ~atomic_bool() = default;

    atomic_bool(const atomic_bool&) = delete;

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

    atomic_bool(bool __i) : _M_base(__i) { }

    bool

    operator=(bool __i)

    { return _M_base.operator=(__i); }

    operator bool() const

    { return _M_base.load(); }

    bool

    is_lock_free() const

    { return _M_base.is_lock_free(); }

    void

    store(bool __i, memory_order __m = memory_order_seq_cst)

    { _M_base.store(__i, __m); }

    bool

    load(memory_order __m = memory_order_seq_cst) const

    { return _M_base.load(__m); }

    bool

    exchange(bool __i, memory_order __m = memory_order_seq_cst)

    { return _M_base.exchange(__i, __m); }

    bool

    compare_exchange_weak(bool& __i1, bool __i2, memory_order __m1,

                          memory_order __m2)

    { return _M_base.compare_exchange_weak(__i1, __i2, __m1, __m2); }

    bool

    compare_exchange_weak(bool& __i1, bool __i2,

                          memory_order __m = memory_order_seq_cst)

    { return _M_base.compare_exchange_weak(__i1, __i2, __m); }

    bool

    compare_exchange_strong(bool& __i1, bool __i2, memory_order __m1,

                            memory_order __m2)

    { return _M_base.compare_exchange_strong(__i1, __i2, __m1, __m2); }

    bool

    compare_exchange_strong(bool& __i1, bool __i2,

                            memory_order __m = memory_order_seq_cst)

    { return _M_base.compare_exchange_strong(__i1, __i2, __m); }

  };

} // namespace __atomic2

// _GLIBCXX_END_NAMESPACE

#endif