What is transactional memory? What advantages does it offer over algorithms based on locks? What challenges will need to be overcome before it enters widespread use? Describe the semantics of the...

What is transactional memory? What advantages does it offer over algorithms based on locks? What challenges will need to be overcome before it enters widespread use? Describe the semantics of the HPF/Fortran 95 forall loop. How does it differ from do concurrent? Why might pure functional languages be said to provide a particularly attractive setting for concurrent programming?