boost/interprocess/managed_shared_memory.hpp

   1 //////////////////////////////////////////////////////////////////////////////
   2 //
   3 // (C) Copyright Ion Gaztanaga 2005-2009. 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_SHARED_MEMORY_HPP
  12 #define BOOST_INTERPROCESS_MANAGED_SHARED_MEMORY_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
  21 #include <boost/interprocess/detail/managed_memory_impl.hpp>
  22 #include <boost/interprocess/exceptions.hpp>
  23 #include <boost/interprocess/detail/managed_open_or_create_impl.hpp>
  24 #include <boost/interprocess/shared_memory_object.hpp>
  25 #include <boost/interprocess/creation_tags.hpp>
  26 #include <boost/interprocess/permissions.hpp>
  27
  28 namespace boost {
  29
  30 namespace interprocess {
  31
  32 //!A basic shared memory named object creation class. Initializes the
  33 //!shared memory segment. Inherits all basic functionality from
  34 //!basic_managed_memory_impl<CharType, AllocationAlgorithm, IndexType>*/
  35 template
  36       <
  37          class CharType,
  38          class AllocationAlgorithm,
  39          template<class IndexConfig> class IndexType
  40       >
  41 class basic_managed_shared_memory
  42    : public detail::basic_managed_memory_impl
  43       <CharType, AllocationAlgorithm, IndexType
  44       ,detail::managed_open_or_create_impl<shared_memory_object>::ManagedOpenOrCreateUserOffset>
  45    , private detail::managed_open_or_create_impl<shared_memory_object>
  46 {
  47    /// @cond
  48    public:
  49    typedef shared_memory_object                       device_type;
  50
  51    private:
  52    typedef detail::basic_managed_memory_impl
  53       <CharType, AllocationAlgorithm, IndexType,
  54       detail::managed_open_or_create_impl<shared_memory_object>::ManagedOpenOrCreateUserOffset>   base_t;
  55    typedef detail::managed_open_or_create_impl
  56       <shared_memory_object>                       base2_t;
  57
  58    typedef detail::create_open_func<base_t>        create_open_func_t;
  59
  60    basic_managed_shared_memory *get_this_pointer()
  61    {  return this;   }
  62
  63    private:
  64    typedef typename base_t::char_ptr_holder_t   char_ptr_holder_t;
  65    BOOST_INTERPROCESS_MOVABLE_BUT_NOT_COPYABLE(basic_managed_shared_memory)
  66    /// @endcond
  67
  68    public: //functions
  69
  70    //!Destroys *this and indicates that the calling process is finished using
  71    //!the resource. The destructor function will deallocate
  72    //!any system resources allocated by the system for use by this process for
  73    //!this resource. The resource can still be opened again calling
  74    //!the open constructor overload. To erase the resource from the system
  75    //!use remove().
  76    ~basic_managed_shared_memory()
  77    {}
  78
  79    //!Default constructor. Does nothing.
  80    //!Useful in combination with move semantics
  81    basic_managed_shared_memory()
  82    {}
  83
  84    //!Creates shared memory and creates and places the segment manager.
  85    //!This can throw.
  86    basic_managed_shared_memory(create_only_t create_only, const char *name,
  87                              std::size_t size, const void *addr = 0, const permissions& perm = permissions())
  88       : base_t()
  89       , base2_t(create_only, name, size, read_write, addr,
  90                 create_open_func_t(get_this_pointer(), detail::DoCreate), perm)
  91    {}
  92
  93    //!Creates shared memory and creates and places the segment manager if
  94    //!segment was not created. If segment was created it connects to the
  95    //!segment.
  96    //!This can throw.
  97    basic_managed_shared_memory (open_or_create_t open_or_create,
  98                               const char *name, std::size_t size,
  99                               const void *addr = 0, const permissions& perm = permissions())
 100       : base_t()
 101       , base2_t(open_or_create, name, size, read_write, addr,
 102                 create_open_func_t(get_this_pointer(),
 103                 detail::DoOpenOrCreate), perm)
 104    {}
 105
 106    //!Connects to a created shared memory and its segment manager.
 107    //!in copy_on_write mode.
 108    //!This can throw.
 109    basic_managed_shared_memory (open_copy_on_write_t, const char* name,
 110                                 const void *addr = 0)
 111       : base_t()
 112       , base2_t(open_only, name, copy_on_write, addr,
 113                 create_open_func_t(get_this_pointer(),
 114                 detail::DoOpen))
 115    {}
 116
 117    //!Connects to a created shared memory and its segment manager.
 118    //!in read-only mode.
 119    //!This can throw.
 120    basic_managed_shared_memory (open_read_only_t, const char* name,
 121                                 const void *addr = 0)
 122       : base_t()
 123       , base2_t(open_only, name, read_only, addr,
 124                 create_open_func_t(get_this_pointer(),
 125                 detail::DoOpen))
 126    {}
 127
 128    //!Connects to a created shared memory and its segment manager.
 129    //!This can throw.
 130    basic_managed_shared_memory (open_only_t open_only, const char* name,
 131                                 const void *addr = 0)
 132       : base_t()
 133       , base2_t(open_only, name, read_write, addr,
 134                 create_open_func_t(get_this_pointer(),
 135                 detail::DoOpen))
 136    {}
 137
 138    //!Moves the ownership of "moved"'s managed memory to *this.
 139    //!Does not throw
 140    basic_managed_shared_memory(BOOST_INTERPROCESS_RV_REF(basic_managed_shared_memory) moved)
 141    {
 142       basic_managed_shared_memory tmp;
 143       this->swap(moved);
 144       tmp.swap(moved);
 145    }
 146
 147    //!Moves the ownership of "moved"'s managed memory to *this.
 148    //!Does not throw
 149    basic_managed_shared_memory &operator=(BOOST_INTERPROCESS_RV_REF(basic_managed_shared_memory) moved)
 150    {
 151       basic_managed_shared_memory tmp(boost::interprocess::move(moved));
 152       this->swap(tmp);
 153       return *this;
 154    }
 155
 156    //!Swaps the ownership of the managed shared memories managed by *this and other.
 157    //!Never throws.
 158    void swap(basic_managed_shared_memory &other)
 159    {
 160       base_t::swap(other);
 161       base2_t::swap(other);
 162    }
 163
 164    //!Tries to resize the managed shared memory object so that we have
 165    //!room for more objects.
 166    //!
 167    //!This function is not synchronized so no other thread or process should
 168    //!be reading or writing the file
 169    static bool grow(const char *shmname, std::size_t extra_bytes)
 170    {
 171       return base_t::template grow
 172          <basic_managed_shared_memory>(shmname, extra_bytes);
 173    }
 174
 175    //!Tries to resize the managed shared memory to minimized the size of the file.
 176    //!
 177    //!This function is not synchronized so no other thread or process should
 178    //!be reading or writing the file
 179    static bool shrink_to_fit(const char *shmname)
 180    {
 181       return base_t::template shrink_to_fit
 182          <basic_managed_shared_memory>(shmname);
 183    }
 184
 185    bool flush()
 186    {
 187       return this->base2_t::flush();
 188    }
 189
 190    /// @cond
 191
 192    //!Tries to find a previous named allocation address. Returns a memory
 193    //!buffer and the object count. If not found returned pointer is 0.
 194    //!Never throws.
 195    template <class T>
 196    std::pair<T*, std::size_t> find  (char_ptr_holder_t name)
 197    {
 198       if(base2_t::get_mapped_region().get_mode() == read_only){
 199          return base_t::template find_no_lock<T>(name);
 200       }
 201       else{
 202          return base_t::template find<T>(name);
 203       }
 204    }
 205
 206    /// @endcond
 207 };
 208
 209 }  //namespace interprocess {
 210 }  //namespace boost {
 211
 212 #include <boost/interprocess/detail/config_end.hpp>
 213
 214 #endif   //BOOST_INTERPROCESS_MANAGED_SHARED_MEMORY_HPP
 215