Using valgrind to detect memory leak in mysql c ++ client

I use valgrind to try to find a memory leak, is the mysql C ++ client distributed from mysql.

In both examples (resultset.cpp) and my own program, there is a single 56-byte block that is not freed. In my own program, I tracked a leak when the mysql client was called.

Here are the results when I run the test:

valgrind --leak-check=full --show-reachable=yes ./my-executable

==29858== Memcheck, a memory error detector
==29858== Copyright (C) 2002-2009, and GNU GPL'd, by Julian Seward et al.
==29858== Using Valgrind-3.6.0.SVN-Debian and LibVEX; rerun with -h for copyright info
==29858== Command: ./my-executable
==29858==
==29858==
==29858== HEAP SUMMARY:
==29858==     in use at exit: 56 bytes in 1 blocks
==29858==   total heap usage: 693 allocs, 692 frees, 308,667 bytes allocated
==29858==
==29858== 56 bytes in 1 blocks are still reachable in loss record 1 of 1
==29858==    at 0x4C284A8: malloc (vg_replace_malloc.c:236)
==29858==    by 0x400D334: _dl_map_object_deps (dl-deps.c:506)
==29858==    by 0x4013652: dl_open_worker (dl-open.c:291)
==29858==    by 0x400E9C5: _dl_catch_error (dl-error.c:178)
==29858==    by 0x4012FF9: _dl_open (dl-open.c:583)
==29858==    by 0x7077BCF: do_dlopen (dl-libc.c:86)
==29858==    by 0x400E9C5: _dl_catch_error (dl-error.c:178)
==29858==    by 0x7077D26: __libc_dlopen_mode (dl-libc.c:47)
==29858==    by 0x72E5FEB: pthread_cancel_init (unwind-forcedunwind.c:53)
==29858==    by 0x72E614B: _Unwind_ForcedUnwind (unwind-forcedunwind.c:126)
==29858==    by 0x72E408F: __pthread_unwind (unwind.c:130)
==29858==    by 0x72DDEB4: pthread_exit (pthreadP.h:265)
==29858==
==29858== LEAK SUMMARY:
==29858==    definitely lost: 0 bytes in 0 blocks
==29858==    indirectly lost: 0 bytes in 0 blocks
==29858==      possibly lost: 0 bytes in 0 blocks
==29858==    still reachable: 56 bytes in 1 blocks
==29858==         suppressed: 0 bytes in 0 blocks
==29858==
==29858== For counts of detected and suppressed errors, rerun with: -v
==29858== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 8 from 6)

I have a few questions regarding this:

• How should I interpret the -show-reachable block?
• Is this block useful for me to try to reset the error?
• If the block is not useful, does valgrind have another mechanism that will help me track the leak?
• If not, is there another tool (hopefully OSS on linux) to help me narrow this down?

Thanks in advance.

UPDATE: , pthread_exit. , , . , , - , ?

void
pthread_exit (void *retval)
{
    /*  specific to PTHREAD_TO_WINTHREAD  */

    ExitThread ((DWORD) ((size_t) retval));  /*  thread becomes signalled so its death can be waited upon  */
    /*NOTREACHED*/
    assert (0); return;  /*  void fnc; can't return an error code  */
}