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POSharing class pointers between processes
 

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    <p>I have a server library which my client executable injects into a remote process. It is the server's responsibility to set up some sort of IPC/RPC implementation to allow the client to seamlessly communicate with the remote process.</p> <h2>Update</h2> <p>Take a look at the following server-side header:</p> <pre><code>#include &lt;boost/interprocess/managed_shared_memory.hpp&gt; #include &lt;boost/interprocess/mapped_region.hpp&gt; #include &lt;boost/interprocess/containers/vector.hpp&gt; #include &lt;boost/interprocess/containers/string.hpp&gt; #include &lt;boost/interprocess/allocators/allocator.hpp&gt; using namespace boost::interprocess; typedef allocator&lt;int, managed_shared_memory::segment_manager&gt; ShmIntAllocator; typedef vector&lt;int, ShmIntAllocator&gt; IntVector; class A { public: A(); A(string str, offset_ptr&lt;IntVector&gt; ints) : m_str(string(str)), m_ints(ints) {}; ~A(); string m_str; offset_ptr&lt;IntVector&gt; m_ints; }; class B { public: B(); B(offset_ptr&lt;A&gt; obj) : m_obj(obj); ~B(); VOID DoSomethingUseful() { MessageBoxA(NULL, m_obj-&gt;m_str.c_str(), "SomethingUseful", MB_ICONINFORMATION); } offset_ptr&lt;A&gt; m_obj; }; </code></pre> <p>And here's the server-side implementation:</p> <pre><code>managed_shared_memory g_shm; offset_ptr&lt;A&gt; g_objA = nullptr; PVOID g_hMem = nullptr; BOOL StartServer() // Create a shared memory pool try { g_shm = managed_shared_memory(create_only, "MySharedMem", OVR_MAPSIZE); } catch(interprocess_exception&amp; e) { std::string msg(e.what()); MessageBoxA(NULL, msg.c_str(), "Error", MB_ICONERROR); return FALSE; } // Construct a local class instance const ShmIntAllocator alloc_intVector (g_shm.get_segment_manager()); offset_ptr&lt;IntVector&gt; ints = g_shm.construct&lt;IntVector&gt;(unique_instance)(alloc_intVector); ints-&gt;push_back(10); ints-&gt;push_back(20); ints-&gt;push_back(30); g_objA = new A("Testing", ints); B objB(g_objA); // Copy data into shared memory size_t len = sizeof(objB); // &lt;-- Doesn't seem to make a difference if I set this to be something higher g_hMem = g_shm.allocate(len); std::memcpy(g_hMem, &amp;objB, len); return TRUE; } VOID StopServer() { // Free used resources if(g_objA) { delete g_objA; g_objA = nullptr; } try{ g_shm.destroy&lt;B&gt;(unique_instance); g_shm.deallocate(g_hMem); g_hMem = nullptr; shared_memory_object::remove("MySharedMem"); } catch(interprocess_exception&amp; e) { std::string msg(e.what()); MessageBoxA(NULL, msg.c_str(), "Error", MB_ICONERROR); } } </code></pre> <p>And the client implementation:</p> <pre><code>BOOL Connect() { // Grab the shared memory pool and extract the class managed_shared_memory shm(open_only, "MySharedMem"); std::pair&lt;B*, std::size_t&gt; ret = shm.find&lt;B&gt;(unique_instance); // &lt;-- Always ends up being 0x00000000! B *objB = static_cast&lt;B*&gt;(ret.first); if(!objB) return FALSE; objB-&gt;DoSomethingUseful(); return TRUE; } </code></pre> <p><br/> You'll notice that <code>managed_shared_memory::find()</code> always fails to return a valid pointer to the client. But as far as I can tell, the code is perfectly valid. There are no compiler warnings or errors, and everything appears to run smoothly up until this point.<br/></p> <p>So why is this failing? How can I get this to work as expected?</p>
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