boost/interprocess/managed_mapped_file.hpp

   1 //////////////////////////////////////////////////////////////////////////////
   2 //
   3 // (C) Copyright Ion Gaztanaga 2005-2008. Distributed under the Boost
   4 // Software License, Version 1.0. (See accompanying file
   5 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 //
   7 // See http://www.boost.org/libs/interprocess for documentation.
   8 //
   9 //////////////////////////////////////////////////////////////////////////////
  10
  11 #ifndef BOOST_INTERPROCESS_MANAGED_MAPPED_FILE_HPP
  12 #define BOOST_INTERPROCESS_MANAGED_MAPPED_FILE_HPP
  13
  14 #if (defined _MSC_VER) && (_MSC_VER >= 1200)
  15 #  pragma once
  16 #endif
  17
  18 #include <boost/interprocess/detail/config_begin.hpp>
  19 #include <boost/interprocess/detail/workaround.hpp>
  20 #include <boost/interprocess/detail/managed_open_or_create_impl.hpp>
  21 #include <boost/interprocess/detail/managed_memory_impl.hpp>
  22 #include <boost/interprocess/creation_tags.hpp>
  23 #include <boost/interprocess/detail/file_wrapper.hpp>
  24 #include <boost/interprocess/detail/move.hpp>
  25 #include <boost/interprocess/file_mapping.hpp>
  26
  27 namespace boost {
  28 namespace interprocess {
  29
  30 //!A basic mapped file named object creation class. Initializes the
  31 //!mapped file. Inherits all basic functionality from
  32 //!basic_managed_memory_impl<CharType, AllocationAlgorithm, IndexType>
  33 template
  34       <
  35          class CharType,
  36          class AllocationAlgorithm,
  37          template<class IndexConfig> class IndexType
  38       >
  39 class basic_managed_mapped_file
  40    : public detail::basic_managed_memory_impl
  41       <CharType, AllocationAlgorithm, IndexType
  42       ,detail::managed_open_or_create_impl<detail::file_wrapper>::ManagedOpenOrCreateUserOffset>
  43 {
  44    /// @cond
  45    public:
  46    typedef detail::basic_managed_memory_impl
  47       <CharType, AllocationAlgorithm, IndexType,
  48       detail::managed_open_or_create_impl<detail::file_wrapper>::ManagedOpenOrCreateUserOffset>   base_t;
  49    typedef detail::file_wrapper device_type;
  50    basic_managed_mapped_file(basic_managed_mapped_file&);
  51    basic_managed_mapped_file & operator=(basic_managed_mapped_file&);
  52
  53    private:
  54
  55    typedef detail::create_open_func<base_t>        create_open_func_t;
  56    typedef detail::managed_open_or_create_impl<detail::file_wrapper> managed_open_or_create_type;
  57
  58    basic_managed_mapped_file *get_this_pointer()
  59    {  return this;   }
  60
  61    private:
  62    typedef typename base_t::char_ptr_holder_t   char_ptr_holder_t;
  63    /// @endcond
  64
  65    public: //functions
  66    BOOST_INTERPROCESS_ENABLE_MOVE_EMULATION(basic_managed_mapped_file)
  67
  68    //!Creates mapped file and creates and places the segment manager.
  69    //!This can throw.
  70    basic_managed_mapped_file()
  71    {}
  72
  73    //!Creates mapped file and creates and places the segment manager.
  74    //!This can throw.
  75    basic_managed_mapped_file(create_only_t create_only, const char *name,
  76                              std::size_t size, const void *addr = 0)
  77       : m_mfile(create_only, name, size, read_write, addr,
  78                 create_open_func_t(get_this_pointer(), detail::DoCreate))
  79    {}
  80
  81    //!Creates mapped file and creates and places the segment manager if
  82    //!segment was not created. If segment was created it connects to the
  83    //!segment.
  84    //!This can throw.
  85    basic_managed_mapped_file (open_or_create_t open_or_create,
  86                               const char *name, std::size_t size,
  87                               const void *addr = 0)
  88       : m_mfile(open_or_create, name, size, read_write, addr,
  89                 create_open_func_t(get_this_pointer(),
  90                 detail::DoOpenOrCreate))
  91    {}
  92
  93    //!Connects to a created mapped file and its segment manager.
  94    //!This can throw.
  95    basic_managed_mapped_file (open_only_t open_only, const char* name,
  96                               const void *addr = 0)
  97       : m_mfile(open_only, name, read_write, addr,
  98                 create_open_func_t(get_this_pointer(),
  99                 detail::DoOpen))
 100    {}
 101
 102    //!Connects to a created mapped file and its segment manager
 103    //!in copy_on_write mode.
 104    //!This can throw.
 105    basic_managed_mapped_file (open_copy_on_write_t, const char* name,
 106                               const void *addr = 0)
 107       : m_mfile(open_only, name, copy_on_write, addr,
 108                 create_open_func_t(get_this_pointer(),
 109                 detail::DoOpen))
 110    {}
 111
 112    //!Connects to a created mapped file and its segment manager
 113    //!in read-only mode.
 114    //!This can throw.
 115    basic_managed_mapped_file (open_read_only_t, const char* name,
 116                               const void *addr = 0)
 117       : m_mfile(open_only, name, read_only, addr,
 118                 create_open_func_t(get_this_pointer(),
 119                 detail::DoOpen))
 120    {}
 121
 122    //!Moves the ownership of "moved"'s managed memory to *this.
 123    //!Does not throw
 124    basic_managed_mapped_file(BOOST_INTERPROCESS_RV_REF(basic_managed_mapped_file) moved)
 125    {
 126       this->swap(moved);
 127    }
 128
 129    //!Moves the ownership of "moved"'s managed memory to *this.
 130    //!Does not throw
 131    basic_managed_mapped_file &operator=(BOOST_INTERPROCESS_RV_REF(basic_managed_mapped_file) moved)
 132    {
 133       basic_managed_mapped_file tmp(boost::interprocess::move(moved));
 134       this->swap(tmp);
 135       return *this;
 136    }
 137
 138    //!Destroys *this and indicates that the calling process is finished using
 139    //!the resource. The destructor function will deallocate
 140    //!any system resources allocated by the system for use by this process for
 141    //!this resource. The resource can still be opened again calling
 142    //!the open constructor overload. To erase the resource from the system
 143    //!use remove().
 144    ~basic_managed_mapped_file()
 145    {}
 146
 147    //!Swaps the ownership of the managed mapped memories managed by *this and other.
 148    //!Never throws.
 149    void swap(basic_managed_mapped_file &other)
 150    {
 151       base_t::swap(other);
 152       m_mfile.swap(other.m_mfile);
 153    }
 154
 155    //!Flushes cached data to file.
 156    //!Never throws
 157    bool flush()
 158    {  return m_mfile.flush();  }
 159
 160    //!Tries to resize mapped file so that we have room for
 161    //!more objects.
 162    //!
 163    //!This function is not synchronized so no other thread or process should
 164    //!be reading or writing the file
 165    static bool grow(const char *filename, std::size_t extra_bytes)
 166    {
 167       return base_t::template grow
 168          <basic_managed_mapped_file>(filename, extra_bytes);
 169    }
 170
 171    //!Tries to resize mapped file to minimized the size of the file.
 172    //!
 173    //!This function is not synchronized so no other thread or process should
 174    //!be reading or writing the file
 175    static bool shrink_to_fit(const char *filename)
 176    {
 177       return base_t::template shrink_to_fit
 178          <basic_managed_mapped_file>(filename);
 179    }
 180
 181    /// @cond
 182
 183    //!Tries to find a previous named allocation address. Returns a memory
 184    //!buffer and the object count. If not found returned pointer is 0.
 185    //!Never throws.
 186    template <class T>
 187    std::pair<T*, std::size_t> find  (char_ptr_holder_t name)
 188    {
 189       if(m_mfile.get_mapped_region().get_mode() == read_only){
 190          return base_t::template find_no_lock<T>(name);
 191       }
 192       else{
 193          return base_t::template find<T>(name);
 194       }
 195    }
 196
 197    private:
 198    managed_open_or_create_type m_mfile;
 199    /// @endcond
 200 };
 201
 202 }  //namespace interprocess {
 203 }  //namespace boost {
 204
 205 #include <boost/interprocess/detail/config_end.hpp>
 206
 207 #endif   //BOOST_INTERPROCESS_MANAGED_MAPPED_FILE_HPP