atomic_std.h

/******************************************************************************
The MIT License(MIT)
 
Embedded Template Library.
https://github.com/ETLCPP/etl
https://www.etlcpp.com
 
Copyright(c) 2018 John Wellbelove
 
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******************************************************************************/
 
#ifndef ETL_ATOMIC_STD_INCLUDED
#define ETL_ATOMIC_STD_INCLUDED
 
#include "../platform.h"
#include "../char_traits.h"
#include "../nullptr.h"
 
#include <atomic>
#include <stdint.h>
 
namespace etl
{
  //***************************************************************************
  // ETL Atomic type for compilers that support std::atomic.
  // etl::atomic is a wrapper around std::atomic that adds fetch_max and
  // fetch_min if the standard library does not yet provide them.
  //***************************************************************************
 
#if ETL_HAS_STD_ATOMIC_MIN_MAX
  // The standard library already provides fetch_max/fetch_min.
  template <typename T>
  using atomic = std::atomic<T>;
#else
  template <typename T>
  class atomic : public std::atomic<T>
  {
    using base_type = std::atomic<T>;
 
  public:
 
    atomic() ETL_NOEXCEPT = default;
 
    ETL_CONSTEXPR atomic(T desired) ETL_NOEXCEPT
      : base_type(desired)
    {
    }
 
    atomic(const atomic&)                     = delete;
    atomic& operator=(const atomic&)          = delete;
    atomic& operator=(const atomic&) volatile = delete;
 
    using base_type::operator=;
 
    // Fetch max
    T fetch_max(T v, std::memory_order order = std::memory_order_seq_cst)
    {
      T old = this->load(order);
 
      while (v > old)
      {
        if (this->compare_exchange_weak(old, v, order))
        {
          break;
        }
      }
 
      return old;
    }
 
    T fetch_max(T v, std::memory_order order = std::memory_order_seq_cst) volatile
    {
      T old = this->load(order);
 
      while (v > old)
      {
        if (this->compare_exchange_weak(old, v, order))
        {
          break;
        }
      }
 
      return old;
    }
 
    // Fetch min
    T fetch_min(T v, std::memory_order order = std::memory_order_seq_cst)
    {
      T old = this->load(order);
 
      while (v < old)
      {
        if (this->compare_exchange_weak(old, v, order))
        {
          break;
        }
      }
 
      return old;
    }
 
    T fetch_min(T v, std::memory_order order = std::memory_order_seq_cst) volatile
    {
      T old = this->load(order);
 
      while (v < old)
      {
        if (this->compare_exchange_weak(old, v, order))
        {
          break;
        }
      }
 
      return old;
    }
  };
#endif
 
  using memory_order = std::memory_order;
 
  static ETL_CONSTANT etl::memory_order memory_order_relaxed = std::memory_order_relaxed;
  static ETL_CONSTANT etl::memory_order memory_order_consume = std::memory_order_consume;
  static ETL_CONSTANT etl::memory_order memory_order_acquire = std::memory_order_acquire;
  static ETL_CONSTANT etl::memory_order memory_order_release = std::memory_order_release;
  static ETL_CONSTANT etl::memory_order memory_order_acq_rel = std::memory_order_acq_rel;
  static ETL_CONSTANT etl::memory_order memory_order_seq_cst = std::memory_order_seq_cst;
 
  using atomic_bool    = etl::atomic<bool>;
  using atomic_char    = etl::atomic<char>;
  using atomic_schar   = etl::atomic<signed char>;
  using atomic_uchar   = etl::atomic<unsigned char>;
  using atomic_short   = etl::atomic<short>;
  using atomic_ushort  = etl::atomic<unsigned short>;
  using atomic_int     = etl::atomic<int>;
  using atomic_uint    = etl::atomic<unsigned int>;
  using atomic_long    = etl::atomic<long>;
  using atomic_ulong   = etl::atomic<unsigned long>;
  using atomic_llong   = etl::atomic<long long>;
  using atomic_ullong  = etl::atomic<unsigned long long>;
  using atomic_wchar_t = etl::atomic<wchar_t>;
#if ETL_HAS_NATIVE_CHAR8_T
  using atomic_char8_t = etl::atomic<char8_t>;
#endif
#if ETL_HAS_NATIVE_CHAR16_T
  using atomic_char16_t = etl::atomic<char16_t>;
#endif
#if ETL_HAS_NATIVE_CHAR32_T
  using atomic_char32_t = etl::atomic<char32_t>;
#endif
#if ETL_USING_8BIT_TYPES
  using atomic_uint8_t = etl::atomic<uint8_t>;
  using atomic_int8_t  = etl::atomic<int8_t>;
#endif
  using atomic_uint16_t = etl::atomic<uint16_t>;
  using atomic_int16_t  = etl::atomic<int16_t>;
  using atomic_uint32_t = etl::atomic<uint32_t>;
  using atomic_int32_t  = etl::atomic<int32_t>;
#if ETL_USING_64BIT_TYPES
  using atomic_uint64_t = etl::atomic<uint64_t>;
  using atomic_int64_t  = etl::atomic<int64_t>;
#endif
  using atomic_int_least8_t   = etl::atomic<int_least8_t>;
  using atomic_uint_least8_t  = etl::atomic<uint_least8_t>;
  using atomic_int_least16_t  = etl::atomic<int_least16_t>;
  using atomic_uint_least16_t = etl::atomic<uint_least16_t>;
  using atomic_int_least32_t  = etl::atomic<int_least32_t>;
  using atomic_uint_least32_t = etl::atomic<uint_least32_t>;
#if ETL_USING_64BIT_TYPES
  using atomic_int_least64_t  = etl::atomic<int_least64_t>;
  using atomic_uint_least64_t = etl::atomic<uint_least64_t>;
#endif
  using atomic_int_fast8_t   = etl::atomic<int_fast8_t>;
  using atomic_uint_fast8_t  = etl::atomic<uint_fast8_t>;
  using atomic_int_fast16_t  = etl::atomic<int_fast16_t>;
  using atomic_uint_fast16_t = etl::atomic<uint_fast16_t>;
  using atomic_int_fast32_t  = etl::atomic<int_fast32_t>;
  using atomic_uint_fast32_t = etl::atomic<uint_fast32_t>;
#if ETL_USING_64BIT_TYPES
  using atomic_int_fast64_t  = etl::atomic<int_fast64_t>;
  using atomic_uint_fast64_t = etl::atomic<uint_fast64_t>;
#endif
  using atomic_intptr_t  = etl::atomic<intptr_t>;
  using atomic_uintptr_t = etl::atomic<uintptr_t>;
  using atomic_size_t    = etl::atomic<size_t>;
  using atomic_ptrdiff_t = etl::atomic<ptrdiff_t>;
  using atomic_intmax_t  = etl::atomic<intmax_t>;
  using atomic_uintmax_t = etl::atomic<uintmax_t>;
} // namespace etl
 
#endif