Describe a plausible implementation of C++ destructors or Java try... finally blocks. What code must the compiler generate, at what points in the program, to ensure that cleanup always occurs when...

Describe a plausible implementation of C++ destructors or Java try... finally blocks. What code must the compiler generate, at what points in the program, to ensure that cleanup always occurs when leaving a scope? Use threads to build support for true iterators in Java. Try to hide as much of the implementation as possible behind a reasonable interface. In particular, hide any uses of new thread, thread.start, thread.join, wait, and notify inside implementations of routines named yield (to be called by an iterator) and in the standard Java Iterator interface routines (to be called in the body of a loop). Compare the performance of your iterators to that of the built-in iterator objects (it probably won’t be good). Discuss any weaknesses you encounter in the abstraction facilities of the language.