Re: [boost] clang-3.6 thread sanitizer complains on shared_ptr operations

Subject: Re: [boost] clang-3.6 thread sanitizer complains on shared_ptr operations
From: Vicente J. Botet Escriba (vicente.botet_at_[hidden])
Date: 2015-01-21 00:57:34

Le 21/01/15 00:50, Gaetano Mendola a écrit :
> I'm using clang 3.6 with boost 1.54
>
> $ clang-3.6 --version
> Ubuntu clang version 3.6.0-svn225356-1~exp1 (trunk) (based on LLVM 3.6.0)
> Target: x86_64-pc-linux-gnu
> Thread model: posix
>
> Compiling the code here: http://pastebin.com/zh0SPz5n
>
> $ clang++-3.6 -g main.cpp -lboost_system -lboost_thread -fsanitize=thread
>
> I get at runtime:
>
>
> ==================
> WARNING: ThreadSanitizer: data race (pid=5592)
> <snip>
> SUMMARY: ThreadSanitizer: data race ??:0 operator delete(void*)
> ==================
>
>
> I believe this is a false alarm indeed the two threads are working on their own shared_ptr copy and thePtr shared pointer
> write/read in the two threads is protected with a mutex.
>
> I will open a ticket with clang folks if you recognize that is a false alarm, unless they are right and we have issue in
> shared_ptr implementation.
>
>
Thanks for raising this issue. The Boost.Thread regression tests are 
showing this kind of issues since the testers were installed by Marshall.

Your example seems to show that the issue is only related to 
boost::shared_ptr. In order we can concentrate only on Boost::SmartPtr, 
could you give a try replacing Boost.Thread by 
(std::thread/mutex/unique_lock)?

Best,
Vicente