Chris@16: //////////////////////////////////////////////////////////////////////////////
Chris@16: //
Chris@16: // (C) Copyright Ion Gaztanaga 2005-2012.
Chris@16: // (C) Copyright Gennaro Prota 2003 - 2004.
Chris@16: //
Chris@16: // Distributed under the Boost Software License, Version 1.0.
Chris@16: // (See accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: //
Chris@16: // See http://www.boost.org/libs/interprocess for documentation.
Chris@16: //
Chris@16: //////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: #ifndef BOOST_INTERPROCESS_DETAIL_UTILITIES_HPP
Chris@16: #define BOOST_INTERPROCESS_DETAIL_UTILITIES_HPP
Chris@16: 
Chris@101: #ifndef BOOST_CONFIG_HPP
Chris@101: #  include <boost/config.hpp>
Chris@101: #endif
Chris@101: #
Chris@101: #if defined(BOOST_HAS_PRAGMA_ONCE)
Chris@16: #  pragma once
Chris@16: #endif
Chris@16: 
Chris@16: #include <boost/interprocess/detail/config_begin.hpp>
Chris@16: #include <boost/interprocess/detail/workaround.hpp>
Chris@16: 
Chris@16: #include <boost/interprocess/interprocess_fwd.hpp>
Chris@101: #include <boost/move/utility_core.hpp>
Chris@16: #include <boost/interprocess/detail/min_max.hpp>
Chris@16: #include <boost/interprocess/detail/type_traits.hpp>
Chris@16: #include <boost/interprocess/detail/mpl.hpp>
Chris@16: #include <boost/intrusive/pointer_traits.hpp>
Chris@101: #include <boost/move/utility_core.hpp>
Chris@16: #include <boost/static_assert.hpp>
Chris@16: #include <climits>
Chris@16: 
Chris@16: namespace boost {
Chris@16: namespace interprocess {
Chris@16: namespace ipcdetail {
Chris@16: 
Chris@16: template <class T>
Chris@16: inline T* to_raw_pointer(T* p)
Chris@16: {  return p; }
Chris@16: 
Chris@16: template <class Pointer>
Chris@16: inline typename boost::intrusive::pointer_traits<Pointer>::element_type*
Chris@16: to_raw_pointer(const Pointer &p)
Chris@16: {  return boost::interprocess::ipcdetail::to_raw_pointer(p.operator->());  }
Chris@16: 
Chris@16: //Rounds "orig_size" by excess to round_to bytes
Chris@16: template<class SizeType>
Chris@16: inline SizeType get_rounded_size(SizeType orig_size, SizeType round_to)
Chris@16: {
Chris@16:    return ((orig_size-1)/round_to+1)*round_to;
Chris@16: }
Chris@16: 
Chris@16: //Truncates "orig_size" to a multiple of "multiple" bytes.
Chris@16: template<class SizeType>
Chris@16: inline SizeType get_truncated_size(SizeType orig_size, SizeType multiple)
Chris@16: {
Chris@16:    return orig_size/multiple*multiple;
Chris@16: }
Chris@16: 
Chris@16: //Rounds "orig_size" by excess to round_to bytes. round_to must be power of two
Chris@16: template<class SizeType>
Chris@16: inline SizeType get_rounded_size_po2(SizeType orig_size, SizeType round_to)
Chris@16: {
Chris@16:    return ((orig_size-1)&(~(round_to-1))) + round_to;
Chris@16: }
Chris@16: 
Chris@16: //Truncates "orig_size" to a multiple of "multiple" bytes. multiple must be power of two
Chris@16: template<class SizeType>
Chris@16: inline SizeType get_truncated_size_po2(SizeType orig_size, SizeType multiple)
Chris@16: {
Chris@16:    return (orig_size & (~(multiple-1)));
Chris@16: }
Chris@16: 
Chris@16: template <std::size_t OrigSize, std::size_t RoundTo>
Chris@16: struct ct_rounded_size
Chris@16: {
Chris@16:    BOOST_STATIC_ASSERT((RoundTo != 0));
Chris@16:    static const std::size_t intermediate_value = (OrigSize-1)/RoundTo+1;
Chris@16:    BOOST_STATIC_ASSERT(intermediate_value <= std::size_t(-1)/RoundTo);
Chris@16:    static const std::size_t value = intermediate_value*RoundTo;
Chris@16: };
Chris@16: 
Chris@16: // Gennaro Prota wrote this. Thanks!
Chris@16: template <int p, int n = 4>
Chris@16: struct ct_max_pow2_less
Chris@16: {
Chris@16:    static const std::size_t c = 2*n < p;
Chris@16: 
Chris@16:    static const std::size_t value =
Chris@16:          c ? (ct_max_pow2_less< c*p, 2*c*n>::value) : n;
Chris@16: };
Chris@16: 
Chris@16: template <>
Chris@16: struct ct_max_pow2_less<0, 0>
Chris@16: {
Chris@16:    static const std::size_t value = 0;
Chris@16: };
Chris@16: 
Chris@16: }  //namespace ipcdetail {
Chris@16: 
Chris@16: //!Trait class to detect if an index is a node
Chris@16: //!index. This allows more efficient operations
Chris@16: //!when deallocating named objects.
Chris@16: template <class Index>
Chris@16: struct is_node_index
Chris@16: {
Chris@16:    static const bool value = false;
Chris@16: };
Chris@16: 
Chris@16: //!Trait class to detect if an index is an intrusive
Chris@16: //!index. This will embed the derivation hook in each
Chris@16: //!allocation header, to provide memory for the intrusive
Chris@16: //!container.
Chris@16: template <class Index>
Chris@16: struct is_intrusive_index
Chris@16: {
Chris@16:    static const bool value = false;
Chris@16: };
Chris@16: 
Chris@16: template <typename T> T*
Chris@16: addressof(T& v)
Chris@16: {
Chris@16:   return reinterpret_cast<T*>(
Chris@16:        &const_cast<char&>(reinterpret_cast<const volatile char &>(v)));
Chris@16: }
Chris@16: 
Chris@16: template<class SizeType>
Chris@16: struct sqrt_size_type_max
Chris@16: {
Chris@16:    static const SizeType value = (SizeType(1) << (sizeof(SizeType)*(CHAR_BIT/2)))-1;
Chris@16: };
Chris@16: 
Chris@16: template<class SizeType>
Chris@16: inline bool multiplication_overflows(SizeType a, SizeType b)
Chris@16: {
Chris@16:    const SizeType sqrt_size_max = sqrt_size_type_max<SizeType>::value;
Chris@101:    return   //Fast runtime check
Chris@16:          (  (a | b) > sqrt_size_max &&
Chris@101:             //Slow division check
Chris@16:             b && a > SizeType(-1)/b
Chris@16:          );
Chris@16: }
Chris@16: 
Chris@16: template<std::size_t SztSizeOfType, class SizeType>
Chris@16: inline bool size_overflows(SizeType count)
Chris@16: {
Chris@16:    //Compile time-check
Chris@16:    BOOST_STATIC_ASSERT(SztSizeOfType <= SizeType(-1));
Chris@16:    //Runtime check
Chris@16:    return multiplication_overflows(SizeType(SztSizeOfType), count);
Chris@16: }
Chris@16: 
Chris@16: template<class RawPointer>
Chris@16: class pointer_size_t_caster
Chris@16: {
Chris@16:    public:
Chris@101:    BOOST_STATIC_ASSERT(sizeof(std::size_t) == sizeof(void*));
Chris@101: 
Chris@16:    explicit pointer_size_t_caster(std::size_t sz)
Chris@16:       : m_ptr(reinterpret_cast<RawPointer>(sz))
Chris@16:    {}
Chris@16: 
Chris@16:    explicit pointer_size_t_caster(RawPointer p)
Chris@16:       : m_ptr(p)
Chris@16:    {}
Chris@16: 
Chris@16:    std::size_t size() const
Chris@16:    {   return reinterpret_cast<std::size_t>(m_ptr);   }
Chris@16: 
Chris@16:    RawPointer pointer() const
Chris@16:    {   return m_ptr;   }
Chris@16: 
Chris@16:    private:
Chris@16:    RawPointer m_ptr;
Chris@16: };
Chris@16: 
Chris@16: 
Chris@16: template<class SizeType>
Chris@16: inline bool sum_overflows(SizeType a, SizeType b)
Chris@16: {  return SizeType(-1) - a < b;  }
Chris@16: 
Chris@16: //Anti-exception node eraser
Chris@16: template<class Cont>
Chris@16: class value_eraser
Chris@16: {
Chris@16:    public:
Chris@16:    value_eraser(Cont & cont, typename Cont::iterator it)
Chris@16:       : m_cont(cont), m_index_it(it), m_erase(true){}
Chris@16:    ~value_eraser()
Chris@16:    {  if(m_erase) m_cont.erase(m_index_it);  }
Chris@16: 
Chris@16:    void release() {  m_erase = false;  }
Chris@16: 
Chris@16:    private:
Chris@16:    Cont                   &m_cont;
Chris@16:    typename Cont::iterator m_index_it;
Chris@16:    bool                    m_erase;
Chris@16: };
Chris@16: 
Chris@16: }  //namespace interprocess {
Chris@16: }  //namespace boost {
Chris@16: 
Chris@16: #include <boost/interprocess/detail/config_end.hpp>
Chris@16: 
Chris@16: #endif   //#ifndef BOOST_INTERPROCESS_DETAIL_UTILITIES_HPP
Chris@16: