Using ThreadSanitizer with std::mutex

[Lundkvist, Herman]

Hello,

 

Is it possible to use ThreadSanitizer with std::mutex and related classes (std::unique_lock, std::lock_guard, etc.)?

 

The following  example:

               // minimal.cpp

#include <thread>

#include <mutex>

 

 

std::mutex g_mutex_;

int g_var = 0;

 

void update() {

    std::lock_guard<std::mutex>{g_mutex_};

    g_var = 1;

}

 

int use() {

    std::lock_guard<std::mutex>{g_mutex_};

    return g_var + 1;

}

 

int main() {

    std::thread t{update};

    use();

    t.join();

    return 0;

}

 

Compiled with:

 

               clang++-9 -o system-std1 -g -pie -fPIE -fsanitize=thread minimal.cpp

 

Gives a data race warning. However, if I replace the std locks with phtead locks, the warning disappears.

 

 

I tried compiling and linking libc++ with “-fsanitize=thread” but the warning persists.

 

Libc++ was compiled from the tag ‘llvmorg-9.0.0’ of https://github.com/llvm/llvm-project

 

mkdir build && cd build

cmake -DCMAKE_C_COMPILER=clang-9 \

        -DCMAKE_CXX_COMPILER=clang++-9 \

        -DLLVM_ENABLE_PROJECTS="libcxx;libcxxabi" \

        -DLLVM_USE_SANITIZER=Thread \

        ../llvm

 

make -j4

 

minimal.cpp was compiled with

 

clang++-9 -o std-with-tsan -stdlib=libc++ -nostdinc++ -g -pie -fPIE -fsanitize=thread \

               -I/home/vsarchelu/src/llvm-project-llvmorg-9.0.0/build-tsan/include/c++/v1 -L/home/vsarchelu/src/llvm-project-llvmorg-9.0.0/build-tsan/lib -Wl,-rpath,/home/vsarchelu/src/llvm-project-llvmorg-9.0.0/build-tsan/lib minimal.cpp

 

I am happy to provide more info if anyone wants to take a look at this.

 

Kind regards,

 

Herman Lundkvist

 

P.S. Some system info:

 

Linux wm-ware guest os on windows host.

 

➜  clang++-9 --version

clang version 9.0.0-2~ubuntu18.04.1 (tags/RELEASE_900/final)

Target: x86_64-pc-linux-gnu

Thread model: posix

InstalledDir: /usr/bin

➜ lsb_release -a

No LSB modules are available.

Distributor ID:    Ubuntu

Description:        Ubuntu 18.04.3 LTS

Release:               18.04

Codename:         bionic