Re: [Boost-users] [Interprocess] Communication between x86 and x64 issue

Subject: Re: [Boost-users] [Interprocess] Communication between x86 and x64 issue
From: Jan Boehme (jan.boehme_at_[hidden])
Date: 2016-02-18 03:11:11

On 07/29/2015 10:02 PM, Toni Neubert wrote:
> I want to communicate between different platforms using boost interprocess.
>
> I am using vc12 and boost 1.58 on windows 7.
>
> My code below is a very simple example, that should work. But it doesn't
> for communications between different platforms...
>
> If I create it in x64 and open in win32, the process stuck at a lock at
> function try_based_lock in boost/int/sync/detail/common_algorithms.hpp
>
> In the other way around: win32 create, x64 open: the process crashes at
> name_length in segment_manager_helper.hpp while trying to find the name
> in index (priv_generic_find in segment_manager).
>
> #include <iostream>
> #include <boost/interprocess/managed_shared_memory.hpp>
>
> int main() {
> namespace bip = boost::interprocess;
>
> // open in WIN32, create in x64
> #ifdef _WIN32
>      bip::managed_shared_memory msm(bip::open_only, "TestIPC");
> #elsif X64
>      bip::shared_memory_object::remove("TestIPC");
>      bip::managed_shared_memory msm(bip::create_only, "TestIPC", 4096);
>      msm.construct<uint32_t>("Data")[1](10);
> #endif
>
> // Get Data and print it
> auto data = msm.find<uint32_t>("Data");
> if (data.second == 1) {
>      std::cout << *data.first << std::endl;
> }
> std::cin.ignore();
>
> return 0;
> }
>
> Does anybody have experience in this? Thank you in advance!

Hello,

some things indicate that's not possible to do with boost::interprocess:

#1 The internal structure, look at the header struct for example, uses data types that are different in length at 32 vs 64 bit arch.

#2 Using a hex editor and looking at the shm for the object shows that there are major differences in the area before your actual data ( which might be safe). The reason for this is #1.And this is the reason for undefined behavior when trying to access it.

Regards, Jan