OS X libstdc++ 可防止 boost::thread 中断

Question

考虑以下示例代码，该代码创建一个线程并使用thread::interrupt调用将其从主线程中断：

#include <iostream>
#include <boost/thread.hpp>
#include <boost/chrono.hpp>
#include <boost/ref.hpp>
int main()
{
    boost::thread t([]{
        int counter = 0;
        while (1){
            std::cout << "interruption enabled " << boost::this_thread::interruption_enabled() << std::endl;
            try {
                counter++;
                if (counter % 5 == 0)
                    throw std::runtime_error("runtime error!");
                std::cout << "thread functionn";
                boost::this_thread::sleep_for(boost::chrono::milliseconds(300));
            }
            catch (boost::thread_interrupted &interruption)
            {
                std::cout << "oops!.. time to finish!" << std::endl;
                return;
                //std::cout << "...but couldn't o_O..." << std::endl;
            }
            catch (std::exception &e)
            {
                std::cout << "some exception: " << e.what() << std::endl;
            }
        }
    });
    boost::this_thread::sleep_for(boost::chrono::milliseconds(3000));
    t.interrupt();
    std::cout << "joinable: " << t.joinable() << std::endl;
    if (t.joinable())
        if (!t.try_join_for(boost::chrono::milliseconds(500)))
        {
            std::cout <<"still RUNNINGn detach it..." << std::endl;
            t.detach();
        }
    std::cout << "main threadn";
    boost::this_thread::sleep_for(boost::chrono::milliseconds(500));
    return 0;
}

现在，当在OS X 10.10.3上像这样编译时（默认情况下使用libc ++）：

g++ main.cpp -I<path_to_boost_1_54_0> -std=gnu++11 -lboost_thread-mt -lboost_system-mt -lboost_chrono-mt -L<path_to_boost_1_54_0>/stage/lib

输出显示中断已启用：

interruption enabled 1
thread function
interruption enabled 1
thread function
...

但是，如果将使用libstdc++：

g++ main.cpp -I<path_to_boost_1_54_0> -std=gnu++11 -stdlib=libstdc++ -lboost_thread-mt -lboost_system-mt -lboost_chrono-mt -L<path_to_boost_1_54_0>/stage/lib

我得到的输出告诉我中断被禁用：

interruption enabled 0
thread function
interruption enabled 0
thread function
...

这种行为有原因吗？我使用了boost v1.54.0和这个LLVM v6.1.0：

$ g++ -v
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 6.1.0 (clang-602.0.49) (based on LLVM 3.6.0svn)
Target: x86_64-apple-darwin14.3.0
Thread model: posix

谢谢

Answer 1

我已经在 Linux 上重现了这个：

• 使用 GCC 4.8、4.9 它可以工作

• 使用 clang 3.5 和 libstdc++ 它可以工作

  interruption enabled 1
  thread function
  interruption enabled 1
  thread function
  interruption enabled 1
  thread function
  interruption enabled 1
  thread function
  interruption enabled 1
  some exception: runtime error!
  interruption enabled 1
  thread function
  interruption enabled 1
  thread function
  interruption enabled 1
  thread function
  interruption enabled 1
  thread function
  interruption enabled 1
  some exception: runtime error!
  interruption enabled 1
  thread function
  interruption enabled 1
  thread function
  joinable: 1
  oops!.. time to finish!
  main thread
  

• 对于 Clang 3.5 和 libc++，它不起作用：

  interruption enabled 128
  thread function
  oops!.. time to finish!
  joinable: 1
  Segmentation fault (core dumped)
  

在我看来，这个问题应该在提升列表中报告。

提升开发人员有可能指出这是libc ++中的一个错误