$ g++ -v Using built-in specs. COLLECT_GCC=g++ COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.7/lto-wrapper Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.7.0~rc1-1ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-4.7/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++,go --prefix=/usr --program-suffix=-4.7 --enable-shared --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.7 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-plugin --enable-objc-gc --disable-werror --with-arch-32=i686 --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu Thread model: posix gcc version 4.7.0 20120302 (prerelease) (Ubuntu/Linaro 4.7.0~rc1-1ubuntu1) $ g++ -static -pthread -std=c++0x -o thread thread.cc $ ./thread pthread_create works std::thread works Segmentation fault $ cat thread.cc #include <thread> #include <iostream> void *foo1(void *) { std::cout << "pthread_create works\n"; return 0; } void foo2() { std::cout << "std::thread works\n"; } int main() { { pthread_t t; pthread_create(&t, 0, foo1, 0); void *r; pthread_join(t, &r); } { std::thread t(foo2); t.join(); } return 0; } I was surprised to see that pthreads worked in this case while std::thread did not. I've also heard that boost::thread works. I'm having a hard time finding any documentation on whether static linking and std::thread should work together. Also see http://stackoverflow.com/questions/7090623/c0x-thread-static-linking-problem If it is the case that pthreads and std::thread cannot work together with static linking, then it'd be nice to fail at some point before runtime if that is possible.
> -static You need to make sure all of libpthread.a is included, right it does not get linked that way. This is not a GCC or glibc bug.
(In reply to comment #1) > > -static > > You need to make sure all of libpthread.a is included, right it does not get > linked that way. > > This is not a GCC or glibc bug. Your comment seems to suggest there is a way, but I can't find it. g++ -Wl,--whole-archive -static -pthread -std=c++0x -o thread thread.cc Gives pages of linker errors. http://sourceware.org/bugzilla/show_bug.cgi?id=10652 suggests glibc and pthreads just don't work with static linking.
$ g++-4.7 -Wl,-M -v -static -pthread -std=c++0x -o thread thread.cc shows all of libpthread being linked. With a bit more digging I traced the problem to /usr/include/c++/4.7.0/x86_64-linux-gnu/bits/gthr-posix.h declaring all of its symbols with __attribute__((weakref)) even when linking statically. Which caused the __gthread_* symbols to resolve to zero. I found this for some background info http://gcc.gnu.org/ml/gcc/2005-10/msg00235.html This change made my example work: $ g++ -D_GLIBCXX_GTHREAD_USE_WEAK=0 -static -pthread -std=c++0x -o thread thread.cc $ ./thread pthread_create works std::thread works However, if I change the code to call std::thread::detach instead of join, then it crashes again with std::thread::detach being resolved to zero. Program received signal SIGSEGV, Segmentation fault. 0x0000000000000000 in ?? () (gdb) bt #0 0x0000000000000000 in ?? () #1 0x0000000000439785 in std::thread::detach() () #2 0x0000000000401f52 in main ()
The weakref attributes are of course correct, the bug is that you aren't linking the whole libpthread.a into the app. On some Linux distributions libpthread.a has all the objects linked together with ld -r and therefore this will just work there, on others you need -Wl,--whole-archive -lpthread -Wl,--no-whole-archive. Better yet don't link statically, there are many reasons why it is a bad idea. http://www.akkadia.org/drepper/no_static_linking.html