hpx::thread::detach suspends while holding locks, leads to hang in debug

[brycelelbach]

I get the following message right before a hang in barrier_test in debug mode.

To reproduce, run barrier_test on a single locality with a single thread.

(T00000000/0000000001dc3038.05/----------------) P00000000/0000000001dc3000.07 02:24.49.558 [000000000000039a]   <debug> [ERR] suspending thread while at least one lock is being held, stack backtrace: 30 frames:
0x7fb56bde237e  : boost::backtrace::backtrace(unsigned long) + 0x80 in /home/wash/hpx/gcc-4.6.2-debug/lib/hpx/libhpxd.so.1
0x7fb56bde24e2  : boost::trace() + 0x1e in /home/wash/hpx/gcc-4.6.2-debug/lib/hpx/libhpxd.so.1
0x7fb56bdd7883  : hpx::detail::backtrace() + 0x18 in /home/wash/hpx/gcc-4.6.2-debug/lib/hpx/libhpxd.so.1
0x7fb56c36629b  : hpx::util::verify_no_locks() + 0x6f in /home/wash/hpx/gcc-4.6.2-debug/lib/hpx/libhpxd.so.1
0x7fb56c06c7cd  : hpx::this_thread::suspend(hpx::threads::thread_state_enum, char const*, hpx::error_code&) + 0x4a in /home/wash/hpx/gcc-4.6.2-debug/lib/hpx/libhpxd.so.1
0x85017f        : hpx::lcos::local::spinlock::yield(unsigned long) + 0x4f in bin/barrier_test
0x85026c        : hpx::lcos::local::spinlock::lock() + 0x2e in bin/barrier_test
0x85e254        : boost::unique_lock<hpx::lcos::local::spinlock>::lock() + 0x44 in bin/barrier_test
0x855d9b        : boost::unique_lock<hpx::lcos::local::spinlock>::unique_lock(hpx::lcos::local::spinlock&) + 0x2f in bin/barrier_test
0x8528b5        : hpx::thread::detach() + 0x1f in bin/barrier_test
0x7fb56c0760b1  : hpx::util::detail::bound_member_function1<void, hpx::thread, hpx::thread* const>::operator()() + 0x77 in /home/wash/hpx/gcc-4.6.2-debug/lib/hpx/libhpxd.so.1
0x7fb56c075f15  : hpx::util::detail::vtable<false>::type<hpx::util::detail::bound_member_function1<void, hpx::thread, hpx::thread* const>, void (), void, void>::invoke_(void**, mpl_::bool_<false>) + 0x1b in /home/wash/hpx/gcc-4.6.2-debug/lib/hpx/libhpxd.so.1
0x7fb56c075c64  : hpx::util::detail::vtable<false>::type<hpx::util::detail::bound_member_function1<void, hpx::thread, hpx::thread* const>, void (), void, void>::invoke(void**) + 0x1b in /home/wash/hpx/gcc-4.6.2-debug/lib/hpx/libhpxd.so.1
0x7fb56beaed3b  : hpx::util::function_base<void (), void, void>::operator()() + 0x53 in /home/wash/hpx/gcc-4.6.2-debug/lib/hpx/libhpxd.so.1
0x7fb56c076615  : hpx::threads::detail::thread_data::run_thread_exit_callbacks() + 0x5d in /home/wash/hpx/gcc-4.6.2-debug/lib/hpx/libhpxd.so.1
0x7fb56c08072d  : hpx::threads::thread_data::run_thread_exit_callbacks() + 0x2f in /home/wash/hpx/gcc-4.6.2-debug/lib/hpx/libhpxd.so.1
0x7fb56c088165  : hpx::threads::threadmanager_impl<hpx::threads::policies::local_priority_queue_scheduler, hpx::threads::policies::callback_notifier>::run_thread_exit_callbacks(void*, hpx::error_code&) + 0x20b in /home/wash/hpx/gcc-4.6.2-debug/lib/hpx/libhpxd.so.1
0x7fb56c06b35e  : hpx::threads::run_thread_exit_callbacks(void*, hpx::error_code&) + 0x1c6 in /home/wash/hpx/gcc-4.6.2-debug/lib/hpx/libhpxd.so.1
0x7fb56c07034b  : ??? + 0x7fb56c07034b in /home/wash/hpx/gcc-4.6.2-debug/lib/hpx/libhpxd.so.1
0x7fb56c0703bd  : hpx::thread::thread_function_nullary(hpx::util::function_nonser<void ()> const&) + 0x23 in /home/wash/hpx/gcc-4.6.2-debug/lib/hpx/libhpxd.so.1
0x7fb56bf17174  : hpx::threads::thread_state_enum hpx::util::detail::bound_function1<hpx::threads::thread_state_enum, hpx::util::function_nonser<void ()> const&, hpx::util::function_nonser<void ()> >::operator()<hpx::threads::thread_state_ex_enum&>(hpx::threads::thread_state_ex_enum&) + 0x66 in /home/wash/hpx/gcc-4.6.2-debug/lib/hpx/libhpxd.so.1
0x7fb56bf16e50  : hpx::util::detail::vtable<false>::type<hpx::util::detail::bound_function1<hpx::threads::thread_state_enum, hpx::util::function_nonser<void ()> const&, hpx::util::function_nonser<void ()> >, hpx::threads::thread_state_enum (hpx::threads::thread_state_ex_enum), void, void>::invoke_(void**, hpx::threads::thread_state_ex_enum, mpl_::bool_<false>) + 0x25 in /home/wash/hpx/gcc-4.6.2-debug/lib/hpx/libhpxd.so.1
0x7fb56bf169df  : hpx::util::detail::vtable<false>::type<hpx::util::detail::bound_function1<hpx::threads::thread_state_enum, hpx::util::function_nonser<void ()> const&, hpx::util::function_nonser<void ()> >, hpx::threads::thread_state_enum (hpx::threads::thread_state_ex_enum), void, void>::invoke(void**, hpx::threads::thread_state_ex_enum) + 0x23 in /home/wash/hpx/gcc-4.6.2-debug/lib/hpx/libhpxd.so.1
0x7fb56c0a616b  : hpx::util::function_base<hpx::threads::thread_state_enum (hpx::threads::thread_state_ex_enum), void, void>::operator()(hpx::threads::thread_state_ex_enum) const + 0x5b in /home/wash/hpx/gcc-4.6.2-debug/lib/hpx/libhpxd.so.1
0x7fb56c0a549a  : hpx::util::coroutines::detail::unpacker_n<hpx::util::coroutines::tuple_traits<hpx::threads::thread_state_ex_enum, boost::tuples::null_type>, 1>::result<hpx::util::function_nonser<hpx::threads::thread_state_enum (hpx::threads::thread_state_ex_enum)> const, boost::tuples::tuple<hpx::threads::thread_state_ex_enum, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >::type hpx::util::coroutines::detail::unpacker_n<hpx::util::coroutines::tuple_traits<hpx::threads::thread_state_ex_enum, boost::tuples::null_type>, 1>::operator()<hpx::util::function_nonser<hpx::threads::thread_state_enum (hpx::threads::thread_state_ex_enum)> const, boost::tuples::tuple<hpx::threads::thread_state_ex_enum, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >(hpx::util::function_nonser<hpx::threads::thread_state_enum (hpx::threads::thread_state_ex_enum)> const&, boost::tuples::tuple<hpx::threads::thread_state_ex_enum, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>&) + 0x30 in /home/wash/hpx/gcc-4.6.2-debug/lib/hpx/libhpxd.so.1
0x7fb56c0a4463  : hpx::util::coroutines::detail::unpacker_n<hpx::util::coroutines::tuple_traits<hpx::threads::thread_state_ex_enum, boost::tuples::null_type>, hpx::util::coroutines::tuple_traits<hpx::threads::thread_state_ex_enum, boost::tuples::null_type>::length>::result<hpx::util::function_nonser<hpx::threads::thread_state_enum (hpx::threads::thread_state_ex_enum)>, boost::tuples::tuple<hpx::threads::thread_state_ex_enum, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >::type hpx::util::coroutines::detail::unpack<hpx::util::coroutines::tuple_traits<hpx::threads::thread_state_ex_enum, boost::tuples::null_type>, hpx::util::function_nonser<hpx::threads::thread_state_enum (hpx::threads::thread_state_ex_enum)>, boost::tuples::tuple<hpx::threads::thread_state_ex_enum, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >(hpx::util::function_nonser<hpx::threads::thread_state_enum (hpx::threads::thread_state_ex_enum)> const&, boost::tuples::tuple<hpx::threads::thread_state_ex_enum, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>&, hpx::util::coroutines::detail::trait_tag<hpx::util::coroutines::tuple_traits<hpx::threads::thread_state_ex_enum, boost::tuples::null_type> >) + 0x27 in /home/wash/hpx/gcc-4.6.2-debug/lib/hpx/libhpxd.so.1
0x7fb56c0a32af  : boost::disable_if<boost::is_void<hpx::threads::thread_state_enum>, void>::type hpx::util::coroutines::detail::coroutine_impl_wrapper<hpx::util::function_nonser<hpx::threads::thread_state_enum (hpx::threads::thread_state_ex_enum)>, hpx::util::coroutines::coroutine<hpx::threads::thread_state_enum (hpx::threads::thread_state_ex_enum), hpx::threads::detail::coroutine_allocator, hpx::util::coroutines::detail::lx::x86_linux_context_impl>, hpx::util::coroutines::detail::lx::x86_linux_context_impl, hpx::threads::detail::coroutine_allocator>::do_call<hpx::threads::thread_state_enum>(hpx::util::coroutines::detail::coroutine_impl_wrapper<hpx::util::function_nonser<hpx::threads::thread_state_enum (hpx::threads::thread_state_ex_enum)>, hpx::util::coroutines::coroutine<hpx::threads::thread_state_enum (hpx::threads::thread_state_ex_enum), hpx::threads::detail::coroutine_allocator, hpx::util::coroutines::detail::lx::x86_linux_context_impl>, hpx::util::coroutines::detail::lx::x86_linux_context_impl, hpx::threads::detail::coroutine_allocator>::dummy<1>) + 0x85 in /home/wash/hpx/gcc-4.6.2-debug/lib/hpx/libhpxd.so.1
0x7fb56c0a188b  : hpx::util::coroutines::detail::coroutine_impl_wrapper<hpx::util::function_nonser<hpx::threads::thread_state_enum (hpx::threads::thread_state_ex_enum)>, hpx::util::coroutines::coroutine<hpx::threads::thread_state_enum (hpx::threads::thread_state_ex_enum), hpx::threads::detail::coroutine_allocator, hpx::util::coroutines::detail::lx::x86_linux_context_impl>, hpx::util::coroutines::detail::lx::x86_linux_context_impl, hpx::threads::detail::coroutine_allocator>::operator()() + 0x5b in /home/wash/hpx/gcc-4.6.2-debug/lib/hpx/libhpxd.so.1
0x7fb56c0a01e4  : void hpx::util::coroutines::detail::lx::trampoline<hpx::util::coroutines::detail::coroutine_impl_wrapper<hpx::util::function_nonser<hpx::threads::thread_state_enum (hpx::threads::thread_state_ex_enum)>, hpx::util::coroutines::coroutine<hpx::threads::thread_state_enum (hpx::threads::thread_state_ex_enum), hpx::threads::detail::coroutine_allocator, hpx::util::coroutines::detail::lx::x86_linux_context_impl>, hpx::util::coroutines::detail::lx::x86_linux_context_impl, hpx::threads::detail::coroutine_allocator> >(hpx::util::coroutines::detail::coroutine_impl_wrapper<hpx::util::function_nonser<hpx::threads::thread_state_enum (hpx::threads::thread_state_ex_enum)>, hpx::util::coroutines::coroutine<hpx::threads::thread_state_enum (hpx::threads::thread_state_ex_enum), hpx::threads::detail::coroutine_allocator, hpx::util::coroutines::detail::lx::x86_linux_context_impl>, hpx::util::coroutines::detail::lx::x86_linux_context_impl, hpx::threads::detail::coroutine_allocator>*) + 0x18 in /home/wash/hpx/gcc-4.6.2-debug/lib/hpx/libhpxd.so.1