Re: [Boost-users] [asio] reported memory leaks when using MFC

30 Oct 2006


      On 10/30/06, Christopher Kohlhoff  wrote:
...
Hi Christian,
Christian Henning wrote:
...
Hi Christopher, thanks for putting so much time into this
issue. I changed the code as you requested, namely I added a
new members to my connection class.
I found another similar problem in image_source::do_write().
I've just implemented a feature for the next version that uses
MSVC's iterator debugging to check the buffer validity. These
program bugs show up as an assertion failure when this new
"buffer debugging" feature is enabled.
I did make the change to all my source classes. A do_write operation
now looks like this:

   void do_write()
   {
      int i = 9;

      std::ostringstream archive_stream;
      boost::archive::binary_oarchive archive( archive_stream );
      archive & i;

      _outbound_data = archive_stream.str();

      std::ostringstream header_stream;
      header_stream << std::setw( 8 )
                     << std::hex
                     << _outbound_data.size();

      _outbound_header = header_stream.str();

      std::vectorboost::asio::const_buffer buffers;
      buffers.push_back(boost::asio::buffer( _outbound_header ));
      buffers.push_back(boost::asio::buffer( _outbound_data   ));

      boost::asio::async_write( _socket
                              , buffers
                              , boost::bind( &image_quality_source::handle_write
                                           , this
                                           ,
boost::asio::placeholders::error     ));
   }

Both the _outbound_heaser and _outbound_data are members of the class.
...
...
But unfortunately nothing has changed. I still have memory
leaks reported. Did you do the change on your machine?
I have now, and I found what I think is the cause of the leak.
Can you please try the following change to
asio/detail/win_iocp_io_service.hpp:
@@ -74,10 +74,11 @@
       DWORD_PTR completion_key = 0;
 #endif
       LPOVERLAPPED overlapped = 0;
-      ::GetQueuedCompletionStatus(iocp_.handle,
+      ::SetLastError(0);
+      BOOL ok = ::GetQueuedCompletionStatus(iocp_.handle,
           &bytes_transferred, &completion_key, &overlapped, 0);
       DWORD last_error = ::GetLastError();
-      if (last_error == WAIT_TIMEOUT)
+      if (!ok && overlapped == 0 && last_error == WAIT_TIMEOUT)
         break;
       if (overlapped)
         static_cast(overlapped)->destroy();
This is most likely offtopic, but how do apply that patch to a source
file? Have never done that. Is there a program I should use?

Thanks Christian

    