Computer Science 322
                         Quiz 9          Name   _____________________

1. When a unix pipe is used to emulate a semaphore:

   a. read() corresponds to wait()       b. pipe() corresponds to wait()
      write() corresponds to signal()       write() corresponds to signal()

   c. write() corresponds to wait()      d. pipe() corresponds to wait()
      read() corresponds to signal()        read() corresponds to signal()


2. The semaphore's "value" corresponds to:

   a. The number of times the pipe      b. The number of pipes that have
      has been read()                      been created

   c. The number of times the pipe      d. The number of bytes presently
      has been written to.                 in the pipe.


3. In the producer / consumer problem, the use of at least one mutex
   semaphore is necessary

   a. When there are multiple           b. Whenever there are multiple
      producers and multiple consumers     producers or muliple consumers.
      but not when there are multiple
      producers and a single consumer.

   c. Always                            d. Never


4. In the producer consumer-problem the consumer:

   a. waits on "items" and signals      b. waits on "slots" and signals
      "items" after consuming.             "items" after consuming.

   c. waits on "items" and signals      d. waits on "slots" and signals
      "slots" after consuming.             "slots" after consuming.


5. Deadlock can occur in a producer/consumer problem when the producers
   and the consumers use the same mutex semaphore and the consumer
   gets the waits in the wrong order:

   a. only when the buffer is full.  b. only when the buffer is empty

   c. whenever the buffer is not     d. whenever the buffer is not full
      empty