Abort in dump() method

[ibc]

What is the issue you have?

Eventually jsonObject.dump() crashes as follows:

#0  0x00007f30680cd428 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:54
#1  0x00007f30680cf02a in __GI_abort () at abort.c:89
#2  0x00007f30681152e8 in __malloc_assert (
    assertion=assertion@entry=0x7f3068229190 "(old_top == initial_top (av) && old_size == 0) || ((unsigned long) (old_size) >= MINSIZE && prev_inuse (old_top) && ((unsigned long) old_end & (pagesize - 1)) == 0)",
    file=file@entry=0x7f3068225bc5 "malloc.c", line=line@entry=2394, function=function@entry=0x7f30682299d8 <__func__.11510> "sysmalloc") at malloc.c:301
#3  0x00007f3068119426 in sysmalloc (nb=nb@entry=1936, av=av@entry=0x7f306845cb20 <main_arena>) at malloc.c:2391
#4  0x00007f306811a743 in _int_malloc (av=av@entry=0x7f306845cb20 <main_arena>, bytes=bytes@entry=1921) at malloc.c:3827
#5  0x00007f306811c184 in __GI___libc_malloc (bytes=1921) at malloc.c:2913
#6  0x00007f3068922e78 in operator new(unsigned long) () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#7  0x00007f30689b4499 in std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_mutate(unsigned long, unsigned long, char const*, unsigned long) () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#8  0x00007f30689b5833 in std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_append(char const*, unsigned long) () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#9  0x00000000005c9e69 in nlohmann::detail::output_string_adapter<char, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::write_characters (this=0x1ebd020,
    s=0x7ffd7146c16a "dtlsState65:FE:25:45:29:D2:87:D8:22:03:0A:54:5E:61:19:27:30:B8:5D:C0:97:B0:D3:E1:D9:CF:CD:EB:E5:19:44:F1:57:84:32:12:21:B6:06:1E:39:03:59:85:63:26:A8:10:B7:51:1E:5C:EF:E7:BB:51:CE:70:1E:6B:60", length=9)
    at ../deps/json/single_include/nlohmann/json.hpp:11274
Python Exception <class 'gdb.error'> There is no member named _M_dataplus.:
#10 0x00000000005cb051 in nlohmann::detail::serializer<nlohmann::basic_json<std::map, std::vector, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool, long, unsigned long, double, std::allocator, nlohmann::adl_serializer> >::dump_escaped (this=0x7ffd7146c110, s=, ensure_ascii=false) at ../deps/json/single_include/nlohmann/json.hpp:14251
#11 0x00000000005c88f2 in nlohmann::detail::serializer<nlohmann::basic_json<std::map, std::vector, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool, long, unsigned long, double, std::allocator, nlohmann::adl_serializer> >::dump (this=0x7ffd7146c110, val=..., pretty_print=false, ensure_ascii=false, indent_step=0, current_indent=0) at ../deps/json/single_include/nlohmann/json.hpp:13897
#12 0x00000000005c8956 in nlohmann::detail::serializer<nlohmann::basic_json<std::map, std::vector, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool, long, unsigned long, double, std::allocator, nlohmann::adl_serializer> >::dump (this=0x7ffd7146c110, val=..., pretty_print=false, ensure_ascii=false, indent_step=0, current_indent=0) at ../deps/json/single_include/nlohmann/json.hpp:13899
#13 0x00000000005c7385 in nlohmann::basic_json<std::map, std::vector, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool, long, unsigned long, double, std::allocator, nlohmann::adl_serializer>::dump (
    this=0x7ffd7146c540, indent=-1, indent_char=32 ' ', ensure_ascii=false, error_handler=nlohmann::detail::error_handler_t::strict) at ../deps/json/single_include/nlohmann/json.hpp:16574
#14 0x00000000005d0938 in Channel::UnixStreamSocket::Send (this=0x1e647f0, jsonMessage=...) at ../src/Channel/UnixStreamSocket.cpp:48

Please describe the steps to reproduce the issue. Can you provide a small but working code example?

Working on it, but it's hard since it happens randomly.

• Which compiler and operating system are you using? Is it a supported compiler?

It does not happen in OSX with Clang. It happens in Linux Debian with gcc 6.3.0 and Ubuntu with 5.4.0 in Docker.

• Did you use a released version of the library or the version from the develop branch?

Latest stable 3.7.3

[ibc]

This seems to be terrible IMHO:

#9  0x00000000005c9e69 in nlohmann::detail::output_string_adapter<char, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::write_characters (this=0x1ebd020,
    s=0x7ffd7146c16a "dtlsState65:FE:25:45:29:D2:87:D8:22:03:0A:54:5E:61:19:27:30:B8:5D:C0:97:B0:D3:E1:D9:CF:CD:EB:E5:19:44:F1:57:84:32:12:21:B6:06:1E:39:03:59:85:63:26:A8:10:B7:51:1E:5C:EF:E7:BB:51:CE:70:1E:6B:60", length=9)
    at ../deps/json/single_include/nlohmann/json.hpp:11274

dtlsState is a root object key and it's value is "connected", "failed" etc. There is a memory corruption here somehow. In fact, eventually I see this when running the binary in a unit test:

*** Error in `/mediasoup/worker/out/Release/mediasoup-worker': corrupted size vs. prev_size: 0x0000000001ff6d60 ***

[ibc]

Let's put this issue on hold. It may be a change introduced in our code that may generate some memory corruption somewhere else.

[ibc]

Bug in our side. Sorry for the noise.