[Boost-users] Boost Shared Memory Compilation Issue

Subject: [Boost-users] Boost Shared Memory Compilation Issue
From: Nathan Lewis (nathanlewissubscription_at_[hidden])
Date: 2011-07-21 13:40:13

Ion Gaztañaga <igaztanaga <at> gmail.com> writes:

> 
> El 20/07/2011 1:55, Nathan Lewis escribió:
> > typedef vector<char_string, char_allocator>
> > char_string_vector_vector;
> 
> ERROR: you must define a vector with a char_string_allocator, not a 
> char_allocator, since you are storing char_string. Attached a working 
> exmple and differences
> 
> Best,
> 
> ion
> 
> 
> 
> 
Thank you for your response. So I made the changes and started the debugger to
see the data in the vector and it turns out it isn't putting the data in the
vector. I assume it is creating it on the heap instead even though it appears to
me I am using the allocator.  I don't know if it is because of the Complex_Data
object is constructed with a void allocator or what. Do you have any thoughts on
what is going on here? I notice that the size of the vector is increasing when
calling the add method but the data is not there

#include <boost/interprocess/managed_shared_memory.hpp>
#include <boost/interprocess/allocators/allocator.hpp>
#include <boost/interprocess/containers/map.hpp>
#include <boost/interprocess/containers/vector.hpp>
#include <boost/interprocess/containers/string.hpp>

using namespace boost::interprocess;
using std::cout;
using std::endl;

//Typedefs of allocators and containers
typedef managed_shared_memory::segment_manager  segment_manager_t;
typedef allocator<void, segment_manager_t>      void_allocator;
typedef allocator<int, segment_manager_t>       int_allocator;
typedef vector<int, int_allocator>              int_vector;
typedef allocator<int_vector, segment_manager_t>int_vector_allocator;
typedef vector<int_vector, int_vector_allocator>int_vector_vector;
typedef allocator<char, segment_manager_t>      char_allocator;
typedef basic_string<char, std::char_traits<char>, char_allocator>   char_string;
typedef allocator<char_string, segment_manager_t> char_string_allocator;
typedef vector<char_string, char_string_allocator>char_string_vector_vector;
typedef char_string_vector_vector::iterator       char_string_vector_iterator;

class complex_data
{
public: //Obviously making the variables of complex_data public isn't a good
idea I am just playing here for the moment
   int                        id_;
   char_string       char_string_;
   char_string_vector_vector char_string_vector_vector_;
   double price_;
   //Since void_allocator is convertible to any other allocator<T>, we simplify
   //the initialization taking just one allocator for all inner containers.
   complex_data(int id, const char *name, double prce, const void_allocator
&void_alloc)
      : id_(id), char_string_(name, void_alloc),
char_string_vector_vector_(void_alloc), price_(prce)
   {}

   // add a string --> Error is on the next line
   //void addStringItem(char_string* s)
   //{char_string_vector_vector_.push_back(*s);}

   void addStringItem(const char* s)
   {
      //Every time you build from a raw string you need an allocator
      //in the constructor
      char_allocator alloc(char_string_vector_vector_.get_allocator());
      char_string_vector_vector_.push_back(char_string(s, alloc));
   }
};

int main ()
{
   //Remove shared memory on construction and destruction
   struct shm_remove
   {
      shm_remove() { shared_memory_object::remove("MySharedMemory"); }
      ~shm_remove(){ shared_memory_object::remove("MySharedMemory"); }
   } remover;

   //Create shared memory
   managed_shared_memory segment(create_only,"MySharedMemory", 65536);

   //An allocator convertible to any allocator<T, segment_manager_t> type
   void_allocator alloc_inst (segment.get_segment_manager());

   char_string tempStr("whatever", alloc_inst);

   cout << "tempStr = " << tempStr << endl;

   //Construct the shared memory map and fill it
   complex_data *mymap = segment.construct<complex_data>("Complex_Data")(7,
"hi", 7.0, alloc_inst);
   mymap->addStringItem("hello");

   cout << "Size of char_string_vector_vector = " <<
mymap->char_string_vector_vector_.size();

   char_string_vector_iterator it = mymap->char_string_vector_vector_.begin();
   while (it != mymap->char_string_vector_vector_.end())
   {
      cout << "Inserted String is: " << endl;
      //cout << "Inserted String is: " << it << endl;
   }
   //cout << "

   //
   return 0;
}