/usr/include/ola/thread/ is in libola-dev 0.10.3.nojsmin-2+deb9u1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/ola/thread/CallbackThread.h
/usr/include/ola/thread/ConsumerThread.h
/usr/include/ola/thread/ExecutorInterface.h
/usr/include/ola/thread/ExecutorThread.h
/usr/include/ola/thread/Future.h
/usr/include/ola/thread/FuturePrivate.h
/usr/include/ola/thread/Mutex.h
/usr/include/ola/thread/PeriodicThread.h
/usr/include/ola/thread/SchedulerInterface.h
/usr/include/ola/thread/SchedulingExecutorInterface.h
/usr/include/ola/thread/SignalThread.h
/usr/include/ola/thread/Thread.h
/usr/include/ola/thread/ThreadPool.h
/usr/include/ola/thread/Utils.h