Re: [asio-users] valgrind reports memory error

[Christopher K. <ch...@ko...>]

On Wed, 27 Jun 2007 14:12:02 +0800, "Cheng Lian" <rhy...@gm...>
said:
> Hi, all
> 
> I'm checking memory leaks in my program. And these lines:
> 
> tcp::resolver resolver( ios );
> tcp::resolver::query query( host, port );
> tcp::resolver::iterator endpoint_iterator = resolver.resolve( query );
> 
> causes the following "valgrind -q" output:
> 
> ==28986== Syscall param socketcall.sendto(msg) points to uninitialised 
> byte(s)
> ==28986==    at 0x5295275: sendto (in /lib/libc-2.3.6.so)
> ==28986==    by 0x52B3899: (within /lib/libc-2.3.6.so)
> ==28986==    by 0x527FF2C: getaddrinfo (in /lib/libc-2.3.6.so)
> ==28986==    by 0x42391B: 
> boost::asio::detail::socket_ops::getaddrinfo(char const*, char const*, 
> addrinfo const*, addrinfo**, boost::system::error_code&) 
> (socket_ops.hpp:1553)
> ==28986==    by 0x423A70: 
> boost::asio::detail::resolver_service<boost::asio::ip::tcp>::resolve(boost::shared_ptr<void>&, 
> boost::asio::ip::basic_resolver_query<boost::asio::ip::tcp> const&, 
> boost::system::error_code&) (resolver_service.hpp:146)
> ==28986==    by 0x423B90: 
> boost::asio::ip::resolver_service<boost::asio::ip::tcp>::resolve(boost::shared_ptr<void>&, 
> boost::asio::ip::basic_resolver_query<boost::asio::ip::tcp> const&, 
> boost::system::error_code&) (resolver_service.hpp:105)
> ==28986==    by 0x423BDC: 
> boost::asio::ip::basic_resolver<boost::asio::ip::tcp, 
> boost::asio::ip::resolver_service<boost::asio::ip::tcp> 
>  >::resolve(boost::asio::ip::basic_resolver_query<boost::asio::ip::tcp> 
> const&) (basic_resolver.hpp:98)
> ==28986==    by 0x4058B8: main (echo_client.cpp:39)
> ==28986==  Address 0x7FEFFFD11 is on thread 1's stack
> 
> Seems that some memory range is not initialized? I'm sorry that I've got 
> no time to track this down, since it's not really so important and 
> doesn't affect my program functionalities.

Yes, I have seen this before. I believe it's a "problem" in the linux
getaddrinfo implementation, not asio code. You can see in the stack that
it refers to a sendto() call inside getaddrinfo().

Cheers,
Chris