extern struct timespec iv_now;
iv_now is a global variable that represents a monotonic timer.
The contents of iv_now might be stale. Calling the function iv_validate_now ensures that the current contents of iv_now are up-to-date.
The function iv_invalidate_now is called to invalidate the currently cached time. This function should be called after any operation that takes a significant amount of wall clock time.
The man pages iv_invalidate_now(3) and iv_validate_now(3) are aliases of iv_time(3).