diff options
| -rw-r--r-- | libstdc++-v3/include/bits/std_thread.h | 24 | ||||
| -rw-r--r-- | libstdc++-v3/src/c++11/thread.cc | 10 |
2 files changed, 25 insertions, 9 deletions
diff --git a/libstdc++-v3/include/bits/std_thread.h b/libstdc++-v3/include/bits/std_thread.h index adbd392..e88c07f 100644 --- a/libstdc++-v3/include/bits/std_thread.h +++ b/libstdc++-v3/include/bits/std_thread.h @@ -132,6 +132,22 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION thread() noexcept = default; #ifdef _GLIBCXX_HAS_GTHREADS + private: + // This adds to user code that creates std:thread objects (because + // it is called by the template ctor below) strong references to + // pthread_create and pthread_join, which ensures they are both + // linked in even during static linking. We can't depend on + // gthread calls to bring them in, because those may use weak + // references. + static void + _M_thread_deps_never_run() { +#ifdef GTHR_ACTIVE_PROXY + reinterpret_cast<void (*)(void)>(&pthread_create)(); + reinterpret_cast<void (*)(void)>(&pthread_join)(); +#endif + } + + public: template<typename _Callable, typename... _Args, typename = _Require<__not_same<_Callable>>> explicit @@ -142,18 +158,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION "std::thread arguments must be invocable after conversion to rvalues" ); -#ifdef GTHR_ACTIVE_PROXY - // Create a reference to pthread_create, not just the gthr weak symbol. - auto __depend = reinterpret_cast<void(*)()>(&pthread_create); -#else - auto __depend = nullptr; -#endif using _Wrapper = _Call_wrapper<_Callable, _Args...>; // Create a call wrapper with DECAY_COPY(__f) as its target object // and DECAY_COPY(__args)... as its bound argument entities. _M_start_thread(_State_ptr(new _State_impl<_Wrapper>( std::forward<_Callable>(__f), std::forward<_Args>(__args)...)), - __depend); + _M_thread_deps_never_run); } #endif // _GLIBCXX_HAS_GTHREADS diff --git a/libstdc++-v3/src/c++11/thread.cc b/libstdc++-v3/src/c++11/thread.cc index 2d5ffaf..c91f7b0 100644 --- a/libstdc++-v3/src/c++11/thread.cc +++ b/libstdc++-v3/src/c++11/thread.cc @@ -154,8 +154,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION } void - thread::_M_start_thread(_State_ptr state, void (*)()) + thread::_M_start_thread(_State_ptr state, void (*depend)()) { + // Make sure it's not optimized out, not even with LTO. + asm ("" : : "rm" (depend)); + if (!__gthread_active_p()) { #if __cpp_exceptions @@ -190,8 +193,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION } void - thread::_M_start_thread(__shared_base_type __b, void (*)()) + thread::_M_start_thread(__shared_base_type __b, void (*depend)()) { + // Make sure it's not optimized out, not even with LTO. + asm ("" : : "rm" (depend)); + auto ptr = __b.get(); // Create a reference cycle that will be broken in the new thread. ptr->_M_this_ptr = std::move(__b); |