1 / 13

Programming Project #2

Programming Project #2. CS-502 Operating Systems Spring 2006. Programming Assignment. Write a mailbox package for communicating among threads. Test your package with a simple program addem that uses multiple threads to add numbers.

tawana
Download Presentation

Programming Project #2

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Programming Project #2 CS-502 Operating SystemsSpring 2006 CS502 Spring 2006

  2. Programming Assignment • Write a mailbox package for communicating among threads. • Test your package with a simple program addem that uses multiple threads to add numbers. • Use your package to implement a multi-threaded version of the game of Life. CS502 Spring 2006

  3. Purpose • To practice writing concurrent programs that share resources and information • To practice using the Linux pthread and semaphore facilities • To practice structuring a system facility in terms of its interface and implementation CS502 Spring 2006

  4. Part 0: Mailboxes • msg structure:– struct msg { int iFrom; // who sent message (thread #) int type; // type (part of payload) int value1;// 1st value (part of payload) int value2;// 2nd value (part of payload) } • Operations • SendMsg(int iTo, struct msg *pMsg) • RecvMsg(int iFrom, struct msg *pMsg) • InitMailboxes(int number_of_mailboxes) • CleanupMailboxes() • Each mailbox can hold at most one message CS502 Spring 2006

  5. Operations on Mailboxes • SendMsg(int iTo, struct msg *pMsg) • Copies contents of pMsg* into mailbox iTo • Blocks if mailbox is already full • RecvMsg(int iFrom, struct msg *pMsg) • Receives contents from mailbox iFrom, copies to pMsg* • Blocks if mailbox is empty • InitMailboxes(int number_of_mailboxes) • Creates an array of mailboxes, each comprising an instance of msg and the necessary semaphores • Initializes the semaphores to indicate mailboxes are empty • CleanupMailboxes() • Deletes the array of mailboxes and the semaphores CS502 Spring 2006

  6. Semaphores #include <semaphore.h> • Operations of interest:– • sem_init() • sem_wait() • sem_post() • sem_destroy() • … CS502 Spring 2006

  7. Implementation of Mailboxes • Implement as a module or package • Mailbox.h as interface • Defines msg and all operations • Mailbox.c as implementation • Hides all details from client • Especially semaphores! CS502 Spring 2006

  8. Part 1: addem • Purpose: to test and exercise the Mailbox package • Command line • % addem nM • Uses n threads to add the numbers from 1 to M • Main thread is thread_0 • Includes pthread.h, Mailbox.h • Reads and parses command line • Initializes n+1 mailboxes using InitMailboxes() • Creates n worker threads, dispatches part of task to each thread via SendMsg • Get results via RecvMsg, combines and prints results. • Cleans up after itself! CS502 Spring 2006

  9. Part 2: Game of Life • John Conway, Scientific American, April 1970. • Rectangular grid, n m squares • Each square has eight nearest neighbors • May be occupied or unoccupied • Rules for next generation • An occupied square with 0 or 1 occupied neighbors dies of loneliness • An occupied with 4, 5, 6, 7, or 8 neighbors dies of overcrowding • An occupied with 2 or 3 occupied neighbors survives • An unoccupied square with exactly 3 occupied neighbors becomes occupied CS502 Spring 2006

  10. Example • Generation 0: 0 1 0 0 0 0 1 1 1 0 0 0 • Generation 1: 0 0 1 0 0 1 1 0 0 0 0 0 CS502 Spring 2006

  11. Operation • Command line • % life n filename g [print [input]] • Uses n threads to play g generations starting from the position in file filename • Optional arguments print and input are to aid in debugging CS502 Spring 2006

  12. Operation (continued) • Main thread is thread_0 • Includes pthread.h, Mailbox.h • Reads and parses command line • Creates even and odd generation arrays • Initializes even array from file • Initializes n+1 mailboxes using InitMailboxes() • Creates n worker threads, dispatches range of rows to each thread via SendMsg • Loops to compute generations • Sends go message to each thread • Get results via RecvMsg • Combines results into new generation array • Determines whether or not it is time to stop • Cleans up after itself! CS502 Spring 2006

  13. Project Submission • Due Monday, March 6 at start of class • Must run on CS or CCC computers at WPI! • Submit via turnin • command = ‘/cs/bin/turnin’ on CCC machines • classname = ‘cs502’ • assignment = ‘project2’ • Include • Code, makefiles, test files or input, test output • Bring printed copy to class. CS502 Spring 2006

More Related