Which statements about thread models and implementations are true or false? True False Kernel-level threads can be scheduled on different CPUs The "idle thread" or "OOM reaper" are kernel-level threads The kernel manages some parts of user-level threads via specific syscalls A user-level threading library needs to implement its own scheduling policy A user-level threading library can theoritically create millions of concurrent Which of the following functions are "multithread safe" (aka reentrant)? Meaning that they can be called by multiple threads concurrently. (Note that you can find out this info in each function's manpage) Multithread safe Multithread unsafe printf() random_r() strerror() ctime_r() memcpy()