COSC 4330                    FINAL                             8/11/98

Closed Book.   You can have one sheet of notes.

1.   For each of the  statements below, indicate  in  one  sentence
     whether or not the statement is true or false, and why (5 points
     each):
     
     a)   There is no easy way to implement the at most once semantics in
          remote procedure calls.
     
     b)   If your computer has a test and set instruction, you do not need
          semaphores to avoid busy waits.

     c)   One page fault every five hundred references is an acceptable
          page fault rate for a virtual memory system.

     d)   The LRU policy always expels the page that has been the least
          frequently referenced since it was brought into main memory.

     e)   There is no efficient way to pass huge arrays in a remote
           procedure call.

     f)    Dynamic address translation is normally done by the software.
  
2.   A computer has 32 bit addresses and a page size of one
     kilobyte.(2×5 points)
     
     a)   How many bits are used to represent the page number ? ____ bits
          
     b)   What is the maximum number of entries in a process page table?
          _________ entries

3.   What  is  the  difference  between  internal  fragmentation   and
     external fragmentation? (10 points)  Which of them wastes more memory
     than the other and what can be done about it?  (2×5 points)

4.   Compare and contrast semaphores and monitor conditions? (2×5 points)

5.   What are the major advantage and disadvantage of the FIFO  page
     replacement policy? (2×5 points)  Name a page replacement policy that
     uses FIFO and explain what it does to correct the deficiencies of that
     policy. (2×5 points)
     
 
--IMPORTANT----IMPORTANT----IMPORTANT----IMPORTANT----IMPORTANT--
Please do not try to answer these questions by yourself BEFORE
having a clear idea of what's on the test for which you are
studying.

Materials covered in each test DO VARY from semester to semester
because the pace of the course can change, some materials are be
added and other deleted almost every semester.
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