Create a shared-memory vector of strings

Question

I am trying to create a class managing a shared-memory vector of (std)strings.

typedef boost::interprocess::allocator

        

Answer 1

You can use boost::interprocess::managed_shared_memory. The following program passes a boost::interprocess::string between 2 processes. Works fine on my machine (Ubuntu Linux). You can use managed_shared_memory to pass vectors or objects. boost::interprocess::string has a c_str() method.

#include 
#include 
#include 
#include 
#include 
#include 
#include 

int main(int argc, char *argv[])
{
  using namespace boost::interprocess;
  typedef boost::interprocess::allocator CharAllocator;
  typedef boost::interprocess::basic_string, CharAllocator> string;
  if(argc == 1){  //Parent process

      boost::interprocess::shared_memory_object::remove("MySharedMemory");

      //Create a shared memory object.
      managed_shared_memory shm (create_only, "MySharedMemory", 1024);

      string *s = shm.find_or_construct("String")("Hello!", shm.get_segment_manager());
      std::cout << *s << std::endl;

      //Launch child process
      std::string s1(argv[0]); s1 += " child ";
      if(0 != std::system(s1.c_str()))
         return 1;
  }
  else{
      //Open already created shared memory object.
      managed_shared_memory shm (open_only, "MySharedMemory");
      std::pair ret = shm.find("String");
      std::cout << *(ret.first) << std::endl;
  }
  return 0;
}