CSC 469F | Assignments | Fall 2006

Assignments

• Assignment 0: Benchmarking (Out: Sept.21, 9:30 p.m. Extended to: October 10, 5:00 p.m.)
  • Simple reservation system for benchmarking machines is now available. See the web page for instructions.
• Assignment 1: Concurrent Hash Table (Out: October 16, Due: October 31)
  • Submission Please submit a printout of your code and documentation (comments in code explaining your strategy is fine, as is a separate document), using the dropbox in BA 2220.
    Please also submit softcopy using the submit command on CDF (e.g. create a gzipped tarfile of all your code and any README or other documentation files, and then "submit -c csc469h -a A1 a1.tgz").
  • Update 2: Two sample traces available on CDF at ~csc469h/fall/pub/A1/traces.tar. New code distribution with two bug fixes to driver.c available (as of 9:21 a.m., Oct. 18). Changes:
    • driver.c, line 203 - comparison should be with msg.body.page, not page
    • driver.c, line 223 - marking PG_READY should be outside of if statement.
  • Update: Original code distribution was slightly stale. New version now out (as of 12:09 p.m. Tuesday, Oct. 17). Changes:
    • prefetch_stats.h - reduced MAX_OUTSTANDING_PREFETCHES from 1024 to 64. This is just a more realistic size for the hash table for the scale of tests we'll be running on the simulation.
    • handlers.c - added integer counter for non-prefetched page fault events (nopf_faults), and code in dump_pf_stats() to print this counter out.
• Assignment 2: Multiprocessor Scheduling Comparison (Out: November 5, Due: November 17)
• Assignment 3: Distributed Programming (Out: November 20, Due: December 1)
  NOTES:
  • Instructions for pretty-printing C code were truncated on the original handout - the current version has been corrected, and the command is included here:

    seawolf% enscript --mark-wrapped-lines=box --header='demke|$n|page $% of $=' -C \
    --highlight=c -p A3.ps client.h client_main.c client_recv.c client_util.c
    

    Make sure you replace 'demke' with your team's login ids in the header argument.
  • IPC message queue cleanup: the client code given out uses a unique temporary file name to create the IPC message queue key (this allows you to run multiple copies of the chat client from the same directory, without having them inadvertently all share the same control <--> receiver message queue). If the client does not exit cleanly however, the temporary file is not deleted and the message queue is not destroyed. Files in /tmp are cleaned up nightly, but IPC message queues are not, and there is a system-wide limit on the number that are allowed. Please use the ipcs and ipcrm commands to find and delete your message queues as follows:

    werewolf% ipcs -q
    
    ------ Message Queues --------
    key        msqid      owner      perms      used-bytes   messages
    0x2a0b0126 12681231   demke      600        0            0
    
    werewolf% ipcrm -q 12681231
    

  • Public chat server is up and running - its log file can be read on CDF at ~csc469h/fall/pub/A3/chatserver.log, in case this helps diagnose any problems with your code. Idle user names and chat rooms are swept clean hourly (defs.h defines a KEEPALIVE message you can use to keep your client connected, but it is not required). For the next two days, the server will be as stable as we can manage. Thereafter, it will fail and restart with random port numbers on a regular 10-minute cycle.
  • To test failure detection and recovery in your client, begin with a local version of the chat server using port numbers that you select. Run the chat client under GDB, so you can better control where the client is at the time the server fails (that is, when you kill it). Make sure your client notices that the server has failed, then restart the server with the same port numbers and step the client through the recovery. Once that is working, it should be straightforward to query the location server for the new chat server parameters, rather than assuming they are known ahead of time. To fully test with a chat client and server that you control, you would need to modify the way your chat server announces itself (since you do not have write permission on the 469 public_html directory), and the way your chat client locates the server. Make sure the client code you submit uses the current strategy to locate the server.