CS 3733 Operating Systems, Fall 2005 Assignment 3 Comments

• This assignment was graded on the basis of 30 points.
• When doing timing, keep the overhead of the timing loop as small as possible. Move library calls such as atoi out of the timing loop if possible.
• The server should not call gettimeofday inside the loop in which it processes requests.
• The delay loop (calls to drand48) should be inside of processline.
• The delay loop should be before the response is sent back to the client.
• What does the server do if it gets a line that is too long for it to handle? For the pipe server, there is not a convenient way to handle this.
• In the parallel server, make sure the child process always terminates and does not go back to the start of the loop and read another line.
• Avoid the following:
  if (childpid = fork() > 0)
  This is the same as:
  if (childpid = (fork()>0))
  
• You should have found that the serial and parallel servers performed almost the same. This is because the server is CPU bound so using a child does not allow any overlap of operations unless you have multiple CPUs. On a single CPU system, the parallel server may do better than the serial server if it has to compete with other processes for the CPU.
• You would expect the parallel server to do better than the serial server if you have multiple CPUs or the server was doing some I/O in addition to the CPU calculations.