Editing Reentrant mutex (section)

== Example ==
# Thread A calls function F which acquires a reentrant lock for itself before proceeding
# Thread B calls function F which attempts to acquire a reentrant lock for itself but cannot due to one already outstanding, resulting in either a block (it waits), or a timeout if requested
# Thread A's F calls itself recursively. It already owns the lock, so it will not block itself (no deadlock). This is the central idea of a reentrant mutex, and is what makes it different from a regular lock.
# Thread B's F is still waiting, or has caught the timeout and worked around it
# Thread A's F finishes and releases its lock(s)
# Thread B's F can now acquire a reentrant lock and proceed if it was still waiting