Computer Science 422/622
                         Quiz B          Name   _____________________

1. For each of the following resources identify the deadlock prevention
   mechanism that was described in class as being used in the "real world"

   ___ a. OS internal locks.        1. Declare resource sharable

   ___ b. Memory                    2. Use hierarchical allocation

                                    3. Use preemption

                                    4. Require simultaneous allocation


2. We described 4 conditions that were associated with deadlock
   occurence.  (To refresh your memory... one of them was "Hold and Wait".)
   In order to guarantee that a deadlock over a resource can't occur
   it is NECESSARY to:

   a. Make sure that at least       b. Make sure that all four
      one of the four conditions       of the conditions can't
      can't hold.                      hold.

   c. Make sure that at least
      three of the four conditions
      can't hold.


3. A DEADLOCK always involves

   a. Exactly two processes        b. Exactly three processes

   b. Either two or one processes  d. Two or more processes.


4. In the resource allocation graph approach to deadlock detection
   a deadlock exists:

   a. <==> a knot exists in a           b. <==> a knot exists in a
      single unit graph and <==>           single unit graph and <==>
      a knot  exists in a mulit-unit       a cycle exists in a mulit-unit
      graph.                               graph.

   c. <==> a cycle exists in a           d. <==> a cycle exists in a
      single unit graph and <==>            single unit graph and <==>
      a cycle exists in a mulit-unit        a knot  exists in a multi-unit
      graph.                                graph.

5. Does the following graph include a deadlock?

   a. yes                          b. no