valgrind errors on stream.cc example

[AlexanderZvyagin]

Hi,

valgrind reports errors on stream.cc example. Could someone please-please review the code (I am new to the library, I cannot do this myself yet).

Sasha

[AlexanderZvyagin]

==31364== Thread 2:
==31364== Mismatched free() / delete / delete []
==31364== at 0x4C2BADC: operator delete(void_) (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==31364== by 0x402DAA: std::auto_ptrmsgpack::zone::~auto_ptr() (in /home/zvyagin/Projects/msgpack/msgpack-c.git/example/stream)
==31364== by 0x402959: Server::socket_readable() (in /home/zvyagin/Projects/msgpack/msgpack-c.git/example/stream)
==31364== by 0x401CB9: run_server(void_) (in /home/zvyagin/Projects/msgpack/msgpack-c.git/example/stream)
==31364== by 0x5042F6D: start_thread (pthread_create.c:311)
==31364== by 0x56569CC: clone (clone.S:113)
==31364== Address 0x59348e0 is 0 bytes inside a block of size 8,248 alloc'd
==31364== at 0x4C2A2DB: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==31364== by 0x4E392E1: msgpack_zone_new (zone.c:201)
==31364== by 0x4E35705: msgpack_unpacker_init (unpack.c:207)
==31364== by 0x402461: msgpack::unpacker::unpacker(unsigned long) (in /home/zvyagin/Projects/msgpack/msgpack-c.git/example/stream)
==31364== by 0x40270C: Server::Server(int) (in /home/zvyagin/Projects/msgpack/msgpack-c.git/example/stream)
==31364== by 0x401DC4: main (in /home/zvyagin/Projects/msgpack/msgpack-c.git/example/stream)
==31364==

[redboltz]

Hi Sasha,
Thank you for your report. I believe that this is the same problem as #52

We are trying to find a good way to fix this problem.

Note:
Typical C++ library implementation calls free in the operator delete as follows:
https://github.com/mirrors/gcc/blob/master/libstdc%2B%2B-v3/libsupc%2B%2B/del_op.cc#L46

zone::~zone() and msgpack_zone_free do the same cleanup process as follows:
https://github.com/msgpack/msgpack-c/blob/master/src/msgpack/zone.hpp.erb#L74
https://github.com/msgpack/msgpack-c/blob/master/src/zone.c#L219

[AlexanderZvyagin]

ok, thanks. But I strongly recommend you either to remove the file stream.cc from your examples, or put a BIG-BIG warning to its source code. What happened to me: after a couple of days of work I adopted the msgpack-stream solution to my project (after a small survey of several alternatives). And the final check with valgrind reveals that the official example is buggy. It really, REALLY hurts! Also it does a lot of damage to the project reputation.

Sasha

[nobu-k]

WarShoe, thank you for your suggestion. We removed deprecated function calls from example/stream.cc, so I think it isn't confusing now.