| ////////////////////////////////////////////////////////////////////////////// |
| // |
| // (C) Copyright Ion Gaztanaga 2006-2009. 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> |
| //[doc_managed_copy_on_write |
| #include <boost/interprocess/managed_mapped_file.hpp> |
| #include <fstream> //std::fstream |
| #include <iterator>//std::distance |
| |
| int main() |
| { |
| using namespace boost::interprocess; |
| |
| //Try to erase any previous managed segment with the same name |
| file_mapping::remove("MyManagedFile"); |
| file_mapping::remove("MyManagedFile2"); |
| remove_file_on_destroy destroyer1("MyManagedFile"); |
| remove_file_on_destroy destroyer2("MyManagedFile2"); |
| |
| { |
| //Create an named integer in a managed mapped file |
| managed_mapped_file managed_file(create_only, "MyManagedFile", 65536); |
| managed_file.construct<int>("MyInt")(0u); |
| |
| //Now create a copy on write version |
| managed_mapped_file managed_file_cow(open_copy_on_write, "MyManagedFile"); |
| |
| //Erase the int and create a new one |
| if(!managed_file_cow.destroy<int>("MyInt")) |
| throw int(0); |
| managed_file_cow.construct<int>("MyInt2"); |
| |
| //Check changes |
| if(managed_file_cow.find<int>("MyInt").first && !managed_file_cow.find<int>("MyInt2").first) |
| throw int(0); |
| |
| //Check the original is intact |
| if(!managed_file.find<int>("MyInt").first && managed_file.find<int>("MyInt2").first) |
| throw int(0); |
| |
| { //Dump the modified copy on write segment to a file |
| std::fstream file("MyManagedFile2", std::ios_base::out | std::ios_base::binary); |
| if(!file) |
| throw int(0); |
| file.write(static_cast<const char *>(managed_file_cow.get_address()), managed_file_cow.get_size()); |
| } |
| |
| //Now open the modified file and test changes |
| managed_mapped_file managed_file_cow2(open_only, "MyManagedFile2"); |
| if(managed_file_cow2.find<int>("MyInt").first && !managed_file_cow2.find<int>("MyInt2").first) |
| throw int(0); |
| } |
| { |
| //Now create a read-only version |
| managed_mapped_file managed_file_ro(open_read_only, "MyManagedFile"); |
| |
| //Check the original is intact |
| if(!managed_file_ro.find<int>("MyInt").first && managed_file_ro.find<int>("MyInt2").first) |
| throw int(0); |
| |
| //Check the number of named objects using the iterators |
| if(std::distance(managed_file_ro.named_begin(), managed_file_ro.named_end()) != 1 && |
| std::distance(managed_file_ro.unique_begin(), managed_file_ro.unique_end()) != 0 ) |
| throw int(0); |
| } |
| return 0; |
| } |
| //] |
| #include <boost/interprocess/detail/config_end.hpp> |