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//////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Ion Gaztanaga 2006-2007.
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
// See http://www.boost.org/libs/interprocess for documentation.
//
//////////////////////////////////////////////////////////////////////////////
#include <boost/interprocess/detail/config_begin.hpp>
#include <boost/interprocess/detail/workaround.hpp>
//[doc_unique_ptr
#include <boost/interprocess/managed_mapped_file.hpp>
#include <boost/interprocess/smart_ptr/unique_ptr.hpp>
#include <boost/interprocess/containers/vector.hpp>
#include <boost/interprocess/containers/list.hpp>
#include <boost/interprocess/allocators/allocator.hpp>
#include <cassert>
#include <cstdio> //std::remove
using namespace boost::interprocess;
//This is type of the object we'll allocate dynamically
struct MyType
{
MyType(int number = 0)
: number_(number)
{}
int number_;
};
//This is the type of a unique pointer to the previous type
//that will be built in the mapped file
typedef managed_unique_ptr<MyType, managed_mapped_file>::type unique_ptr_type;
//Define containers of unique pointer. Unique pointer simplifies object management
typedef vector
< unique_ptr_type
, allocator<unique_ptr_type, managed_mapped_file::segment_manager>
> unique_ptr_vector_t;
typedef list
< unique_ptr_type
, allocator<unique_ptr_type, managed_mapped_file::segment_manager>
> unique_ptr_list_t;
int main ()
{
//Destroy any previous file with the name to be used.
std::remove("MyMappedFile");
{
managed_mapped_file file(create_only, "MyMappedFile", 65536);
//Construct an object in the file and
//pass ownership to this local unique pointer
unique_ptr_type local_unique_ptr (make_managed_unique_ptr
(file.construct<MyType>("unique object")(), file));
assert(local_unique_ptr.get() != 0);
//Reset the unique pointer. The object is automatically destroyed
local_unique_ptr.reset();
assert(file.find<MyType>("unique object").first == 0);
//Now create a vector of unique pointers
unique_ptr_vector_t *unique_vector =
file.construct<unique_ptr_vector_t>("unique vector")(file.get_segment_manager());
//Speed optimization
unique_vector->reserve(100);
//Now insert all values
for(int i = 0; i < 100; ++i){
unique_vector->push_back(
make_managed_unique_ptr(file.construct<MyType>(anonymous_instance)(i), file)
);
assert(unique_vector->back()->number_ == i);
}
//Now create a list of unique pointers
unique_ptr_list_t *unique_list =
file.construct<unique_ptr_list_t>("unique list")(file.get_segment_manager());
//Pass ownership of all values to the list
for(int i = 99; !unique_vector->empty(); --i){
unique_list->push_front(move(unique_vector->back()));
//The unique ptr of the vector is now empty...
assert(unique_vector->back() == 0);
unique_vector->pop_back();
//...and the list has taken ownership of the value
assert(unique_list->front() != 0);
assert(unique_list->front()->number_ == i);
}
assert(unique_list->size() == 100);
//Now destroy the empty vector.
file.destroy_ptr(unique_vector);
//The mapped file is unmapped here. Objects have been flushed to disk
}
{
//Reopen the mapped file and find again the list
managed_mapped_file file(open_only, "MyMappedFile");
unique_ptr_list_t *unique_list =
file.find<unique_ptr_list_t>("unique list").first;
assert(unique_list);
assert(unique_list->size() == 100);
unique_ptr_list_t::const_iterator list_it = unique_list->begin();
for(int i = 0; i < 100; ++i, ++list_it){
assert((*list_it)->number_ == i);
}
//Now destroy the list. All elements will be automatically deallocated.
file.destroy_ptr(unique_list);
}
std::remove("MyMappedFile");
return 0;
}
//]
#include <boost/interprocess/detail/config_end.hpp>
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