OS X libstdc++ prevents boost::thread from interruptions?

问题

Consider the following sample code which creates a thread and interrupts it from the main thread using thread::interrupt call:

#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 function\n";
                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 RUNNING\n detach it..." << std::endl;
            t.detach();
        }

    std::cout << "main thread\n";
    boost::this_thread::sleep_for(boost::chrono::milliseconds(500));

    return 0;
}

Now, when compiled on OS X 10.10.3 like this (libc++ is used by default):

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

the output shows that interruptions are enabled:

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

If, however, one will use 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

I get the output which tells me that interruption are disabled:

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

Is there a reason for such behaviour? I used boost v1.54.0 and this 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

Thanks

回答1:

I've reproduced this on linux:

with gcc 4.8, 4.9 it works

with clang 3.5 and libstdc++ it works

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

with clang 3.5 and libc++ it doesn't work:

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

This issue should be reported at the boost list, in my opinion.

There is a chance that the boost devs will indicate it's a bug in libc++

来源：https://stackoverflow.com/questions/30901904/os-x-libstdc-prevents-boostthread-from-interruptions

标签

multithreading

c++11

boost

libstdc++

libc++