[lld] r248102 - COFF: Fix thread-safety bug.

[David Blaikie via llvm-commits]

On Sat, Sep 19, 2015 at 4:14 PM, Rui Ueyama via llvm-commits <
llvm-commits at lists.llvm.org> wrote:

> Author: ruiu
> Date: Sat Sep 19 18:14:51 2015
> New Revision: 248102
>
> URL: http://llvm.org/viewvc/llvm-project?rev=248102&view=rev
> Log:
> COFF: Fix thread-safety bug.
>
> LTOModule doesn't seem to be thread-safe, so guard that with mutex.
>

Yeah, that seems unfortunate.

Any idea where the thread unsafety comes from & whether we can/should fix
it down the stack rather than in lld?


>
> Modified:
>     lld/trunk/COFF/InputFiles.cpp
>     lld/trunk/COFF/InputFiles.h
>
> Modified: lld/trunk/COFF/InputFiles.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/lld/trunk/COFF/InputFiles.cpp?rev=248102&r1=248101&r2=248102&view=diff
>
> ==============================================================================
> --- lld/trunk/COFF/InputFiles.cpp (original)
> +++ lld/trunk/COFF/InputFiles.cpp Sat Sep 19 18:14:51 2015
> @@ -310,6 +310,9 @@ void ImportFile::parse() {
>  }
>
>  void BitcodeFile::parse() {
> +  // Usually parse() is thread-safe, but bitcode file is an exception.
> +  std::lock_guard<std::mutex> Lock(Mu);
> +
>    std::string Err;
>    M.reset(LTOModule::createFromBuffer(MB.getBufferStart(),
>                                        MB.getBufferSize(),
> @@ -356,5 +359,7 @@ MachineTypes BitcodeFile::getMachineType
>    }
>  }
>
> +std::mutex BitcodeFile::Mu;
> +
>  } // namespace coff
>  } // namespace lld
>
> Modified: lld/trunk/COFF/InputFiles.h
> URL:
> http://llvm.org/viewvc/llvm-project/lld/trunk/COFF/InputFiles.h?rev=248102&r1=248101&r2=248102&view=diff
>
> ==============================================================================
> --- lld/trunk/COFF/InputFiles.h (original)
> +++ lld/trunk/COFF/InputFiles.h Sat Sep 19 18:14:51 2015
> @@ -17,6 +17,7 @@
>  #include "llvm/Object/COFF.h"
>  #include "llvm/Support/StringSaver.h"
>  #include <memory>
> +#include <mutex>
>  #include <set>
>  #include <vector>
>
> @@ -213,6 +214,7 @@ private:
>    std::vector<SymbolBody *> SymbolBodies;
>    llvm::BumpPtrAllocator Alloc;
>    std::unique_ptr<LTOModule> M;
> +  static std::mutex Mu;
>  };
>
>  } // namespace coff
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20150919/59099e4d/attachment.html>