The Reentrant Read Write Lock class provided by the java. util. concur-rent. locks package does not allow a thread holding the lock in read mode to then access that lock in write mode (the thread will...

The Reentrant Read Write Lock class provided by the java. util. concur-rent. locks package does not allow a thread holding the lock in read mode to then access that lock in write mode (the thread will block). Justify this design decision by sketching what it would take to permit such lock upgrades.