This turns a mysterious segfault into an exception with a more useful
message. If the exception isn't caught, the user sees this instead of
just a segfault:
terminate called after throwing an instance of 'std::system_error'
what(): Enable multithreading to use std::thread: Operation not permitted
Aborted (core dumped)
libstdc++-v3/ChangeLog:
PR libstdc++/67791
* src/c++11/thread.cc (thread::_M_start_thread(_State_ptr, void (*)())):
Check that gthreads is available before calling __gthread_create.
(cherry picked from commit
4bbd5d0c5fb2b7527938ad44a6d8a2f2ef8bbe12)
void
thread::_M_start_thread(_State_ptr state, void (*)())
{
+ if (!__gthread_active_p())
+ {
+#if __cpp_exceptions
+ throw system_error(make_error_code(errc::operation_not_permitted),
+ "Enable multithreading to use std::thread");
+#else
+ __builtin_abort();
+#endif
+ }
+
const int err = __gthread_create(&_M_id._M_thread,
&execute_native_thread_routine,
state.get());