Re: [Boost-bugs] [Boost C++ Libraries] #6320: race condition in boost::filesystem::path leads to crash when used in multithreaded programs

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #6320: race condition in boost::filesystem::path leads to crash when used in multithreaded programs
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2017-05-09 15:07:24

#6320: race condition in boost::filesystem::path leads to crash when used in
multithreaded programs
-------------------------------+-------------------------
  Reporter:  aris.basic@…      |      Owner:  bemandawes
      Type:  Bugs              |     Status:  reopened
 Milestone:  To Be Determined  |  Component:  filesystem
   Version:  Boost 1.62.0      |   Severity:  Showstopper
Resolution:                    |   Keywords:
-------------------------------+-------------------------

Comment (by anonymous):

 Replying to [comment:24 stl]:
 > Replying to [comment:23 stl]:
 > > Some simplified code to reproduce the crash. As concurrency bugs are
 timing dependent, this will crash most of the time, but not always.
 > >
 > > {{{
 > > #include <boost/filesystem.hpp>
 > > #include <boost/thread.hpp>
 > >
 > > void thr()
 > >     {
 > >     boost::filesystem::path file(L"C:\\test");
 > >     boost::this_thread::sleep(boost::posix_time::milliseconds(10));
 > >     std::cout << file.string() << std::endl;
 > >     }
 > >
 > >
 > > int main()
 > >     {
 > >     boost::thread_group tg;
 > >     for (size_t n = 0; n < 5; ++n)
 > >             {
 > >             tg.create_thread(thr);
 > >             }
 > >     tg.join_all();
 > >     return 0;
 > >     }
 > >
 > > }}}
 >
 > Of course, this code is meant to reproduce the crash on Windows, where
 boost::filesystem::path uses wide characters natively, and thus must
 convert when using string().

 {{{boost::barrier}}} can help a lot to catch threading issues:

 {{{
 const int num = 10;
 boost::barrier b(num + 1);
 std::vector<std::thread> threads;
 for (int i = 0; i < num; ++i)
         threads.emplace_back([&b] { b.wait();
 boost::filesystem::path::codecvt(); });

 b.wait();

 for (auto& thread: threads)
         thread.join();
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/6320#comment:26>
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