Possible thread deadlock in eassylogging

[ial0]

While looking into issue #214 I ran clang's thread sanitizer, this found a potential deadlock within easylogging++. I'm not sure if this has any bearing on #214 or not could it could be part of the issue.

==================
WARNING: ThreadSanitizer: lock-order-inversion (potential deadlock) (pid=3933)
  Cycle in lock order graph: M11 (0x7d480000be90) => M13 (0x7d4400009d90) => M17 (0x7d580000fc10) => M11

  Mutex M13 acquired here while holding mutex M11 in main thread:
    #0 pthread_mutex_lock <null> (encfs+0x0000004e1285)
    #1 el::base::threading::internal::Mutex::lock() /home/ial/Devel/Encfs/encfs/internal/easylogging++.h:996:45 (encfs+0x0000005680ec)
    #2 el::base::threading::internal::ScopedLock<el::base::threading::internal::Mutex>::ScopedLock(el::base::threading::internal::Mutex&) /home/ial/Devel/Encfs/encfs/internal/easylogging++.h:1031:54 (encfs+0x000000567f09)
    #3 el::base::RegisteredLoggers::get(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, bool) /home/ial/Devel/Encfs/encfs/internal/easylogging++.h:3673:45 (encfs+0x00000056b26c)
    #4 el::Loggers::getLogger(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, bool) /home/ial/Devel/Encfs/encfs/internal/easylogging++.h:5825:47 (encfs+0x0000005e01e5)
    #5 el::Loggers::reconfigureLogger(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, el::Configurations const&) /home/ial/Devel/Encfs/encfs/internal/easylogging++.h:5846:47 (encfs+0x0000005e0069)
    #6 encfs::initLogging(bool) /home/ial/Devel/Encfs/encfs/encfs/Error.cpp:20:3 (encfs+0x0000005df77e)
    #7 main /home/ial/Devel/Encfs/encfs/encfs/main.cpp:546:3 (encfs+0x00000055a7fe)

    Hint: use TSAN_OPTIONS=second_deadlock_stack=1 to get more informative warning message

  Mutex M17 acquired here while holding mutex M13 in main thread:
    #0 pthread_mutex_lock <null> (encfs+0x0000004e1285)
    #1 el::base::threading::internal::Mutex::lock() /home/ial/Devel/Encfs/encfs/internal/easylogging++.h:996:45 (encfs+0x0000005680ec)
    #2 el::base::threading::internal::ScopedLock<el::base::threading::internal::Mutex>::ScopedLock(el::base::threading::internal::Mutex&) /home/ial/Devel/Encfs/encfs/internal/easylogging++.h:1031:54 (encfs+0x000000567f09)
    #3 el::Logger::configure(el::Configurations const&) /home/ial/Devel/Encfs/encfs/internal/easylogging++.h:3486:41 (encfs+0x000000584158)
    #4 el::Logger::Logger(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, el::Configurations const&, std::map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::shared_ptr<std::basic_fstream<char, std::char_traits<char> > >, std::less<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, std::shared_ptr<std::basic_fstream<char, std::char_traits<char> > > > > >*) /home/ial/Devel/Encfs/encfs/internal/easylogging++.h:3441:13 (encfs+0x000000583c7c)
    #5 el::base::RegisteredLoggers::get(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, bool) /home/ial/Devel/Encfs/encfs/internal/easylogging++.h:3681:35 (encfs+0x00000056b52b)
    #6 el::base::Storage::Storage(std::shared_ptr<el::LogBuilder> const&) /home/ial/Devel/Encfs/encfs/internal/easylogging++.h:3972:38 (encfs+0x00000056252c)
    #7 __cxx_global_var_init.4 /home/ial/Devel/Encfs/encfs/encfs/main.cpp:61:1 (encfs+0x0000004c094e)
    #8 _GLOBAL__sub_I_main.cpp /home/ial/Devel/Encfs/encfs/encfs/main.cpp (encfs+0x0000004c0a65)
    #9 __libc_csu_init <null> (encfs+0x000000647e3c)

  Mutex M11 acquired here while holding mutex M17 in main thread:
    #0 pthread_mutex_lock <null> (encfs+0x0000004e1285)
    #1 el::base::threading::internal::Mutex::lock() /home/ial/Devel/Encfs/encfs/internal/easylogging++.h:996:45 (encfs+0x0000005680ec)
    #2 el::base::threading::internal::ScopedLock<el::base::threading::internal::Mutex>::ScopedLock(el::base::threading::internal::Mutex&) /home/ial/Devel/Encfs/encfs/internal/easylogging++.h:1031:54 (encfs+0x000000567f09)
    #3 el::base::LogDispatcher::dispatch() /home/ial/Devel/Encfs/encfs/internal/easylogging++.h:4508:45 (encfs+0x0000005a9871)
    #4 el::base::Writer::triggerDispatch() /home/ial/Devel/Encfs/encfs/internal/easylogging++.h:5090:92 (encfs+0x0000005a8e53)
    #5 el::base::Writer::processDispatch() /home/ial/Devel/Encfs/encfs/internal/easylogging++.h:5073:25 (encfs+0x0000005a8ad0)
    #6 el::base::Writer::~Writer() /home/ial/Devel/Encfs/encfs/internal/easylogging++.h:4959:17 (encfs+0x000000563ad6)
    #7 main /home/ial/Devel/Encfs/encfs/encfs/main.cpp:548:3 (encfs+0x00000055a925)

SUMMARY: ThreadSanitizer: lock-order-inversion (potential deadlock) (/home/ial/Devel/Encfs/encfs/build/encfs+0x4e1285) in __interceptor_pthread_mutex_lock
==================
2016-11-03 14:03:11,389 VER [main.cpp:548] Root directory: /tmp/a/
2016-11-03 14:03:11,389 VER [main.cpp:549] Fuse arguments: (fg) (threaded) (keyCheck) encfs /tmp/b/ -f -o use_ino -o default_permissions 
2016-11-03 14:03:11,396 VER [FileUtils.cpp:294] found new serialization format
2016-11-03 14:03:11,396 VER [FileUtils.cpp:308] subVersion = 20100713
2016-11-03 14:03:11,396 VER [Interface.cpp:110] checking if ssl/aes(3:0:2) implements ssl/aes(3:0)
2016-11-03 14:03:11,397 VER [SSL_Cipher.cpp:333] allocated cipher ssl/aes, keySize 24, ivlength 16
2016-11-03 14:03:11,397 VER [FileUtils.cpp:1580] useStdin: 0

[abumq]

Please see comment on abumq/easyloggingpp#417

[abumq]

PLEASE SEE IMPORTANT RELEASE NOTE FOR v9.90+ UPGRADE.

The only change you need is to import easylogging++.cc and add it to your source files list. that's it. This is done to speed up compile time as header only can become slow. See this issue for further details

[benrubson]

#298 merged, issue should be solved 👍