[Coin-discuss] potential memory leak in CoinMessageHandler used with Cbc

[Kish Shen]

Hi,

I have been trying to track down this memory leak that shows up with 
valgrind, and I think it seems to happen when I allocate a 
CoinMessageHandler, as in the following:

CoinMessageHandler * coinMessageHandler = new CoinMessageHandler;
delete coinMessageHandler;

when this code is run, valgrind shows:

==4782== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 17 from 1)
==4782== malloc/free: in use at exit: 640 bytes in 1 blocks.
==4782== malloc/free: 5 allocs, 4 frees, 3,712 bytes allocated.
==4782== For counts of detected errors, rerun with: -v
==4782== searching for pointers to 1 not-freed blocks.
==4782== checked 123,620 bytes.
==4782==
==4782== 640 bytes in 1 blocks are still reachable in loss record 1 of 1
==4782==    at 0x401CA9F: operator new(unsigned) (vg_replace_malloc.c:163)
==4782==    by 0x40BE008: std::__default_alloc_template<true, 
0>::_S_chunk_alloc(unsigned, int&) (in /usr/lib/libstdc++.so.5.0.7)
==4782==    by 0x40BE0FC: std::__default_alloc_template<true, 
0>::_S_refill(unsigned) (in /usr/lib/libstdc++.so.5.0.7)
==4782==    by 0x40BE416: std::__default_alloc_template<true, 
0>::allocate(unsigned) (in /usr/lib/libstdc++.so.5.0.7)
==4782==    by 0x40C0C6D: std::string::_Rep::_S_create(unsigned, 
std::allocator<char> const&) (in /usr/lib/libstdc++.so.5.0.7)
==4782==    by 0x40C26F4: std::string::_M_mutate(unsigned, unsigned, 
unsigned) (in /usr/lib/libstdc++.so.5.0.7)
==4782==    by 0x40C2868: std::string& std::string::_M_replace_safe<char 
const*>(__gnu_cxx::__normal_iterator<char*, std::string>, 
__gnu_cxx::__normal_iterator<char*, std::string>, char const*, char 
const*) (in /usr/lib/libstdc++.so.5.0.7)
==4782==    by 0x40C2963: std::string::assign(char const*, unsigned) (in 
/usr/lib/libstdc++.so.5.0.7)
==4782==    by 0x40C2AD4: std::string::operator=(char const*) (in 
/usr/lib/libstdc++.so.5.0.7)
==4782==    by 0x830EEC0: CoinMessageHandler::CoinMessageHandler() 
(CoinMessageHandler.cpp:440)
==4782==    by 0x804E551: coin_create_prob (coinplex.cpp:1430)
==4782==    by 0x8383780: step_00 (bug.c:6)
==4782==
==4782== LEAK SUMMARY:
==4782==    definitely lost: 0 bytes in 0 blocks.
==4782==      possibly lost: 0 bytes in 0 blocks.
==4782==    still reachable: 640 bytes in 1 blocks.
==4782==         suppressed: 0 bytes in 0 blocks.

coin_create_prob is where the above code is define. It is the only call 
made.

The above is a much simplified version of the calls I made, and the leak 
shows up as `still reachable'. In the actual code I use, this 640 bytes 
shows up as definitely lost.

I am using the trunk branch of Cbc that I downloaded on 14 Nov 2008.
Line 440 of CoinMessageHandler.cpp is

   source_="Unk";

in CoinMessageHandler::CoinMessageHandler()

Any suggestions on how I could prevent this leak with be most welcomed!

Cheers,

Kish

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