[Boost-users] How to use interprocess communication to load the data into map

Subject: [Boost-users] How to use interprocess communication to load the data into map
From: manish4gupta (manish_at_[hidden])
Date: 2009-09-13 23:55:29

Hi,
I am using boost interprocess library for loading the data into map <string,
string> . And reading the same map with another program.I am benchmarking
the code given on the following lilnk.
http://www.boost.org/doc/libs/1_38_0/doc/html/interproc/quick_guide.html#interprocess.quick_guide.qg_interprocess_map

#include <boost/interprocess/managed_shared_memory.hpp>
#include <boost/interprocess/containers/map.hpp>
#include <boost/interprocess/allocators/allocator.hpp>
#include <functional>
#include <utility>

int main ()
{
   using namespace boost::interprocess;
   //Shared memory front-end that is able to construct objects
   //associated with a c-string. Erase previous shared memory with the name
   //to be used and create the memory segment at the specified address and
initialize resources
   shared_memory_object::remove("MySharedMemory");

   try{
      managed_shared_memory segment
         (create_only
         ,"MySharedMemory" //segment name
         ,65536);          //segment size in bytes

      //Note that map<Key, MappedType>'s value_type is std::pair<const Key,
MappedType>,
      //so the allocator must allocate that pair.
      typedef int    KeyType;
      typedef float  MappedType;
      typedef std::pair<const int, float> ValueType;

      //Alias an STL compatible allocator of for the map.
      //This allocator will allow to place containers
      //in managed shared memory segments
      typedef allocator<ValueType, managed_shared_memory::segment_manager>
         ShmemAllocator;

      //Alias a map of ints that uses the previous STL-like allocator.
      //Note that the third parameter argument is the ordering function
      //of the map, just like with std::map, used to compare the keys.
      typedef map<KeyType, MappedType, std::less<KeyType>, ShmemAllocator>
MyMap;

      //Initialize the shared memory STL-compatible allocator
      ShmemAllocator alloc_inst (segment.get_segment_manager());

      //Construct a shared memory map.
      //Note that the first parameter is the comparison function,
      //and the second one the allocator.
      //This the same signature as std::map's constructor taking an
allocator
      MyMap *mymap =
         segment.construct<MyMap>("MyMap")      //object name
                                    (std::less<int>() //first  ctor
parameter
                                    ,alloc_inst);     //second ctor
parameter

      //Insert data in the map
      for(int i = 0; i < 100; ++i){
         mymap->insert(std::pair<const int, float>(i, (float)i));
      }
   }
   catch(...){
      shared_memory_object::remove("MySharedMemory");
      throw;
   }
   shared_memory_object::remove("MySharedMemory");
   return 0;
}

but getting the following errors.

manish_at_user-desktop:~/Desktop$ g++ memorymap.cpp
/tmp/ccmOQCB8.o: In function
`boost::interprocess::shared_memory_object::priv_open_or_create(boost::interprocess::detail::create_enum_t,
char const*, boost::interprocess::mode_t)':
memorymap.cpp:(.text._ZN5boost12interprocess20shared_memory_object19priv_open_or_createENS0_6detail13create_enum_tEPKcNS0_6mode_tE[boost::interprocess::shared_memory_object::priv_open_or_create(boost::interprocess::detail::create_enum_t,
char const*, boost::interprocess::mode_t)]+0x163): undefined reference to
`shm_open'
/tmp/ccmOQCB8.o: In function
`boost::interprocess::detail::mutexattr_wrapper::mutexattr_wrapper(bool)':
memorymap.cpp:(.text._ZN5boost12interprocess6detail17mutexattr_wrapperC1Eb[boost::interprocess::detail::mutexattr_wrapper::mutexattr_wrapper(bool)]+0x14):
undefined reference to `pthread_mutexattr_init'
memorymap.cpp:(.text._ZN5boost12interprocess6detail17mutexattr_wrapperC1Eb[boost::interprocess::detail::mutexattr_wrapper::mutexattr_wrapper(bool)]+0x2b):
undefined reference to `pthread_mutexattr_setpshared'
memorymap.cpp:(.text._ZN5boost12interprocess6detail17mutexattr_wrapperC1Eb[boost::interprocess::detail::mutexattr_wrapper::mutexattr_wrapper(bool)]+0x4d):
undefined reference to `pthread_mutexattr_settype'
/tmp/ccmOQCB8.o: In function
`boost::interprocess::detail::mutexattr_wrapper::~mutexattr_wrapper()':
memorymap.cpp:(.text._ZN5boost12interprocess6detail17mutexattr_wrapperD1Ev[boost::interprocess::detail::mutexattr_wrapper::~mutexattr_wrapper()]+0xd):
undefined reference to `pthread_mutexattr_destroy'
/tmp/ccmOQCB8.o: In function
`boost::interprocess::shared_memory_object::remove(char const*)':
memorymap.cpp:(.text._ZN5boost12interprocess20shared_memory_object6removeEPKc[boost::interprocess::shared_memory_object::remove(char
const*)]+0x33): undefined reference to `shm_unlink'
collect2: ld returned 1 exit stats.

What is the reason for this pblm? Thanks in advance.

Regards
Manish
-- 
View this message in context: http://www.nabble.com/How-to-use-interprocess-communication-to-load-the-data-into-map-tp25429982p25429982.html
Sent from the Boost - Users mailing list archive at Nabble.com.