I compile using Clang with -g3 and -O1 flags, but TSan complains that it found a data-race and it outputs a totally obscure stack trace with no clear line numbers.
How to find line numbers in this case?
Output on Pastebin since Stack Overflow doesn't support more than 30k chars.
Look for "/home" for finding your code.
The stacks of the threads look nice with well shown line numbers. Your MediaServer::initialize() created the thread T1.
Thread T1 (tid=2667937, running) created by main thread at:
#2 MediaServer::initialize /home/MediaServer/MediaServerMethods.cpp:1808
#3 main /home/MediaServer/MediaServer.cpp:33
T1 continued MediaServer initialization and created the thread 7.
Thread T7 (tid=2667963, running) created by thread T1 at:
#31 SimpleWeb::SocketServerBase<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::executor> >::start() /usr/local/include/simple-websocket-server/server_ws.hpp:437
#32 MediaServer::initialize()::$_7::operator()() const /home/MediaServer/MediaServerMethods.cpp:1812
T7 received some message and called your code, that was creating std::shared_ptr that was creating some std::string from a C string perhaps.
Previous write of size 8 at 0x7b1800006060 by thread T7:
#1 void std::__cxx11::basic_string<char>::_M_construct<char*>(char*, char*, std::forward_iterator_tag) /usr/include/c++/11/bits/basic_string.tcc:219
#2 rtc::impl::Certificate::Certificate()
...
#8 std::make_shared<rtc::PeerConnection>() /usr/include/c++/11/bits/shared_ptr.h:876
#9 RTCTransport::createPeerConnection() /home/MediaServer/MediaServerMethods.cpp:458
#10 MediaServer::initialize()::$_5::operator()(...) const /home/MediaServer/MediaServerMethods.cpp:1761
Finally thread T1 was attempting to construct the same std::string without using a lock guard.
WARNING: ThreadSanitizer: data race (pid=2667935)
Read of size 8 at 0x7b1800006060 by thread T1:
#1 void std::__cxx11::basic_string<char>::_M_construct<char*>(char*, char*, std::forward_iterator_tag) /usr/include/c++/11/bits/basic_string.tcc:225
#2 rtc::impl::Certificate::fingerprint[abi:cxx11]() const
...
#24 MediaServer::initialize()::$_7::operator()() const /home/MediaServer/MediaServerMethods.cpp:1812
