Purpose: Create more specific diagrams including collaboration and sequence diagrams for the system. Upgrade the prototype from Iteration 1 to an alpha version.

Due: Writeups: Beginning of class on March 26, 2007

Alpha: 11:59 PM on April 4, 2007, using the turnin script. Late submissions will not be accepted.

Description: For this iteration, you will prepare several diagrams representing use case realizations for the traffic simulator and produce an alpha version.

In this iteration, your simulator will progress to running pretty much a full simulation as specified in the Term Project document. Also, the split between administrator and experimenter is to take shape by implementation of a text based layout creation (and storage) tool. To achieve these ends, you should create object interaction diagrams, along with producing updates from Iteration 1. Specifically, you should submit the following:

From Iteration 1:

Ø Class diagrams, updated to currency.

Ø A use case diagram showing all use cases and all actors. Also, any use cases that are updated

Ø Info on format of a street layout on disk. Submit even if submitted last time

For Iteration 2:

Ø Realizations of use cases Create a Street Layout and Run a Simulation. Create each of the following diagrams for each of these use cases, and one other of your choice:

o Collaboration diagram

o Sequence diagram

o State Diagram

You will implement the simulation to input the starting point and destination, and the number of vehicles, and run them through the layout simultaneously by using threads to create a lightweight process for each one. Each Vehicle will output its results to a file named results.txt, in a well labeled manner. This file will be created if it doesn’t exist, or updated otherwise. Each Vehicle will retain timestamp info for its starting and finishing times off the system clock. Time is measured as the difference of those times, and also by number of intersections in the traversal.

As multiple vehicles will be traversing the layout simultaneously, provisions must be made to ensure that the data written to results.txt is not garbled due to concurrent threads writing to results.txt simultaneously. This will be accomplished by using a mutex to allow only one thread to modify the file at any time. To maximize system throughput, each thread will write its results, all at once, upon completion.

Notes:

· Submit any updates to the diagrams from Iteration 1. Make sure that these updates are clearly labeled as such. Also, submit updated class diagrams.

· Be sure each thread has its own local data for recording timestamps and results.

· You may need to further update the Vehicle class (and maybe its subclasses) to handle the traversal.

· Linker libraries must be specified when using threads. Your linker command must include the appropriate library: –lthread or –lpthread, depending on which thread library you are using.

· Proper documentation and style is expected. The application must be modularly designed.

Turnin:

Writeups: 6 PM March 26, 2007

Alpha: 11:59 PM, April 4, 2007. Turn in all code files, a makefile, and data file(s). You may also submit a readme. The makefile must build an executable named i2.