ceph/src/boost/libs/interprocess/include/boost/interprocess/file_mapping.hpp

   1 //////////////////////////////////////////////////////////////////////////////
   2 //
   3 // (C) Copyright Ion Gaztanaga 2005-2012. 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_FILE_MAPPING_HPP
  12 #define BOOST_INTERPROCESS_FILE_MAPPING_HPP
  13
  14 #ifndef BOOST_CONFIG_HPP
  15 #  include <boost/config.hpp>
  16 #endif
  17 #
  18 #if defined(BOOST_HAS_PRAGMA_ONCE)
  19 #  pragma once
  20 #endif
  21
  22 #include <boost/interprocess/detail/config_begin.hpp>
  23 #include <boost/interprocess/detail/workaround.hpp>
  24
  25 #if !defined(BOOST_INTERPROCESS_MAPPED_FILES)
  26 #error "Boost.Interprocess: This platform does not support memory mapped files!"
  27 #endif
  28
  29 #include <boost/interprocess/interprocess_fwd.hpp>
  30 #include <boost/interprocess/exceptions.hpp>
  31 #include <boost/interprocess/detail/utilities.hpp>
  32 #include <boost/interprocess/creation_tags.hpp>
  33 #include <boost/interprocess/detail/os_file_functions.hpp>
  34 #include <boost/interprocess/detail/simple_swap.hpp>
  35 #include <boost/move/utility_core.hpp>
  36 #include <string>    //std::string
  37
  38 //!\file
  39 //!Describes file_mapping and mapped region classes
  40
  41 namespace boost {
  42 namespace interprocess {
  43
  44 //!A class that wraps a file-mapping that can be used to
  45 //!create mapped regions from the mapped files
  46 class file_mapping
  47 {
  48    #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
  49    BOOST_MOVABLE_BUT_NOT_COPYABLE(file_mapping)
  50    #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
  51
  52    public:
  53    //!Constructs an empty file mapping.
  54    //!Does not throw
  55    file_mapping();
  56
  57    //!Opens a file mapping of file "filename", starting in offset
  58    //!"file_offset", and the mapping's size will be "size". The mapping
  59    //!can be opened for read-only "read_only" or read-write "read_write"
  60    //!modes. Throws interprocess_exception on error.
  61    file_mapping(const char *filename, mode_t mode);
  62
  63    //!Moves the ownership of "moved"'s file mapping object to *this.
  64    //!After the call, "moved" does not represent any file mapping object.
  65    //!Does not throw
  66    file_mapping(BOOST_RV_REF(file_mapping) moved)
  67       :  m_handle(file_handle_t(ipcdetail::invalid_file()))
  68       ,  m_mode(read_only)
  69    {  this->swap(moved);   }
  70
  71    //!Moves the ownership of "moved"'s file mapping to *this.
  72    //!After the call, "moved" does not represent any file mapping.
  73    //!Does not throw
  74    file_mapping &operator=(BOOST_RV_REF(file_mapping) moved)
  75    {
  76       file_mapping tmp(boost::move(moved));
  77       this->swap(tmp);
  78       return *this;
  79    }
  80
  81    //!Swaps to file_mappings.
  82    //!Does not throw.
  83    void swap(file_mapping &other);
  84
  85    //!Returns access mode
  86    //!used in the constructor
  87    mode_t get_mode() const;
  88
  89    //!Obtains the mapping handle
  90    //!to be used with mapped_region
  91    mapping_handle_t get_mapping_handle() const;
  92
  93    //!Destroys the file mapping. All mapped regions created from this are still
  94    //!valid. Does not throw
  95    ~file_mapping();
  96
  97    //!Returns the name of the file
  98    //!used in the constructor.
  99    const char *get_name() const;
 100
 101    //!Removes the file named "filename" even if it's been memory mapped.
 102    //!Returns true on success.
 103    //!The function might fail in some operating systems if the file is
 104    //!being used other processes and no deletion permission was shared.
 105    static bool remove(const char *filename);
 106
 107    #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
 108    private:
 109    //!Closes a previously opened file mapping. Never throws.
 110    void priv_close();
 111    file_handle_t  m_handle;
 112    mode_t         m_mode;
 113    std::string    m_filename;
 114    #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
 115 };
 116
 117 inline file_mapping::file_mapping()
 118    :  m_handle(file_handle_t(ipcdetail::invalid_file()))
 119    ,  m_mode(read_only)
 120 {}
 121
 122 inline file_mapping::~file_mapping()
 123 {  this->priv_close(); }
 124
 125 inline const char *file_mapping::get_name() const
 126 {  return m_filename.c_str(); }
 127
 128 inline void file_mapping::swap(file_mapping &other)
 129 {
 130    (simple_swap)(m_handle, other.m_handle);
 131    (simple_swap)(m_mode, other.m_mode);
 132    m_filename.swap(other.m_filename);
 133 }
 134
 135 inline mapping_handle_t file_mapping::get_mapping_handle() const
 136 {  return ipcdetail::mapping_handle_from_file_handle(m_handle);  }
 137
 138 inline mode_t file_mapping::get_mode() const
 139 {  return m_mode; }
 140
 141 inline file_mapping::file_mapping
 142    (const char *filename, mode_t mode)
 143    :  m_filename(filename)
 144 {
 145    //Check accesses
 146    if (mode != read_write && mode != read_only){
 147       error_info err = other_error;
 148       throw interprocess_exception(err);
 149    }
 150
 151    //Open file
 152    m_handle = ipcdetail::open_existing_file(filename, mode);
 153
 154    //Check for error
 155    if(m_handle == ipcdetail::invalid_file()){
 156       error_info err = system_error_code();
 157       this->priv_close();
 158       throw interprocess_exception(err);
 159    }
 160    m_mode = mode;
 161 }
 162
 163 inline bool file_mapping::remove(const char *filename)
 164 {  return ipcdetail::delete_file(filename);  }
 165
 166 #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
 167
 168 inline void file_mapping::priv_close()
 169 {
 170    if(m_handle != ipcdetail::invalid_file()){
 171       ipcdetail::close_file(m_handle);
 172       m_handle = ipcdetail::invalid_file();
 173    }
 174 }
 175
 176 //!A class that stores the name of a file
 177 //!and tries to remove it in its destructor
 178 //!Useful to remove temporary files in the presence
 179 //!of exceptions
 180 class remove_file_on_destroy
 181 {
 182    const char * m_name;
 183    public:
 184    remove_file_on_destroy(const char *name)
 185       :  m_name(name)
 186    {}
 187
 188    ~remove_file_on_destroy()
 189    {  ipcdetail::delete_file(m_name);  }
 190 };
 191
 192 #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
 193
 194 }  //namespace interprocess {
 195 }  //namespace boost {
 196
 197 #include <boost/interprocess/detail/config_end.hpp>
 198
 199 #endif   //BOOST_INTERPROCESS_FILE_MAPPING_HPP