[SCIP] valgrind issue

[James Cussens]

I am using valgrind to check for memory leaks.

valgrind claims that I do one more alloc than free, so I have been trying
to track down the problem.

Just to be sure I understood what was going on I tried valgrind on the LOP
example that comes with SCIP4.0.0

Running this:
valgrind --leak-check=full --show-leak-kinds=all bin/lop -v

(which just prints out version and build options) produces this valgrind
output

....

ZIMPLOPT=opt
 ZLIB=true
==31777==
==31777== HEAP SUMMARY:
==31777==     in use at exit: 72,704 bytes in 1 blocks
==31777==   total heap usage: 14,256 allocs, 14,255 frees, 1,345,646 bytes
allocated
==31777==
==31777== 72,704 bytes in 1 blocks are still reachable in loss record 1 of 1
==31777==    at 0x4C2DB8F: malloc (in
/usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==31777==    by 0x58ACEFF: ??? (in
/usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.21)
==31777==    by 0x40104E9: call_init.part.0 (dl-init.c:72)
==31777==    by 0x40105FA: call_init (dl-init.c:30)
==31777==    by 0x40105FA: _dl_init (dl-init.c:120)
==31777==    by 0x4000CF9: ??? (in /lib/x86_64-linux-gnu/ld-2.23.so)
==31777==    by 0x1: ???
==31777==    by 0xFFEFFFCAA: ???
==31777==    by 0xFFEFFFCB2: ???
==31777==
==31777== LEAK SUMMARY:
==31777==    definitely lost: 0 bytes in 0 blocks
==31777==    indirectly lost: 0 bytes in 0 blocks
==31777==      possibly lost: 0 bytes in 0 blocks
==31777==    still reachable: 72,704 bytes in 1 blocks
==31777==         suppressed: 0 bytes in 0 blocks
==31777==
==31777== For counts of detected and suppressed errors, rerun with: -v
==31777== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)

This 72,704 bytes that is still reachable when running bin/lop is exactly
the same number of allegedly still reachable bytes
that gets reported when I run my code. So presumably there is a common
issue. Anyone know what is going on?

It looks like I don't have any memory problems since nothing is "lost" (for
me or for LOP) but I would be interested to know what is going on.

When running "hello world" (in C, with no linking to SCIP), valgrind, as
expected tells me that "All heap blocks were freed -- no leaks are
possible", so this is probably
not a valgrind issue.

James

-- 
James Cussens
Dept of Computer Science &
York Centre for Complex Systems Analysis
Room 326, The Hub, Deramore Lane            Tel    +44 (0)1904 325371
University of York                                        Fax  +44 (0)1904
500159
York YO10 5GE, UK                               http://www.cs.york.ac.uk/~jc
http://www.york.ac.uk/docs/disclaimer/email.htm
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