p1

This repository contains the starter code for project 1 (15-440, Fall 2016). It also contains the tests that we will use to grade your implementation, and two simple echo server/client (srunner and crunner, respectively) programs that you might find useful for your own testing purposes. These instructions assume you have set your GOPATH to point to the repository's root p1/ directory.

If at any point you have any trouble with building, installing, or testing your code, the article titled How to Write Go Code is a great resource for understanding how Go workspaces are built and organized. You might also find the documentation for the go command to be helpful. As always, feel free to post your questions on Piazza.

This project was designed for, and tested on AFS cluster machines, though you may choose to write and build your code locally as well.

Part A

Testing your code using srunner & crunner

To make testing your server a bit easier we have provided two simple echo server/client programs called srunner and crunner. If you look at the source code for the two programs, you’ll notice that they import the github.com/cmu440/lsp package (in other words, they compile against the current state of your LSP implementation). We believe you will find these programs useful in the early stages of development when your client and server implementations are largely incomplete.

To compile, build, and run these programs, use the go run command from inside the directory storing the file (these instructions assume your GOPATH is pointing to the project’s root p1/ directory):

go run srunner.go

The srunner and crunner programs may be customized using command line flags. For more information, specify the -h flag at the command line. For example,

$ go run srunner.go -h
Usage of bin/srunner:
  -elim=5: epoch limit
  -ems=2000: epoch duration (ms)
  -port=9999: port number
  -rdrop=0: network read drop percent
  -v=false: show srunner logs
  -wdrop=0: network write drop percent
  -wsize=1: window size

We have also provided pre-compiled executables for you to use called srunner-sols and crunner-sols. These binaries were compiled against our reference LSP implementation, so you might find them useful in the early stages of the development process (for example, if you wanted to test your Client implementation but haven’t finished implementing the Server yet, etc.).Two separate binaries are provided for Linux and Mac OS X machines (Windows is not supported at this time).

As an example, to start an echo server on port 6060 on an AFS cluster machine, execute the following command:

$GOPATH/bin/linux_amd64/srunner-sols -port=6060

Running the tests

To test your submission, we will execute the following command from inside the p1/src/github.com/cmu440/lsp directory for each of the tests (where TestName is the name of one of the 44 test cases, such as TestBasic6 or TestWindow1):

go test -run=TestName

Note that we will execute each test individually using the -run flag and by specify a regular expression identifying the name of the test to run. To ensure that previous tests don’t affect the outcome of later tests, we recommend executing the tests individually (or in small batches, such as go test -run=TestBasic which will execute all tests beginning with TestBasic) as opposed to all together using go test.

On some tests, we will also check your code for race conditions using Go’s race detector:

go test -race -run=TestName

Submitting to Autolab

As with project 0, we will be using Autolab to grade your submissions for this project. We will run some—but not all—of the tests with the race detector enabled.

To submit your code to Autolab, create a lsp.tar file containing your LSP implementation as follows:

cd p1/src/github.com/cmu440/
tar -cvf lsp.tar lsp/

Part B

Importing the bitcoin package

In order to use the starter code we provide in the hash.go and message.go files, use the following import statement:

import "github.com/cmu440/bitcoin"

Once you do this, you should be able to make use of the bitcoin package as follows:

hash := bitcoin.Hash("thom yorke", 19970521)

msg := bitcoin.NewRequest("jonny greenwood", 200, 71010)

Compiling the client, miner & server programs

To compile the client, miner, and server programs, use the go install command as follows (these instructions assume your GOPATH is pointing to the project's root p1/ directory):

# Compile the client, miner, and server programs. The resulting binaries
# will be located in the $GOPATH/bin directory.
go install github.com/cmu440/bitcoin/client
go install github.com/cmu440/bitcoin/miner
go install github.com/cmu440/bitcoin/server

# Start the server, specifying the port to listen on.
$GOPATH/bin/server 6060

# Start a miner, specifying the server's host:port.
$GOPATH/bin/miner localhost:6060

# Start the client, specifying the server's host:port, the message
# "bradfitz", and max nonce 9999.
$GOPATH/bin/client localhost:6060 bradfitz 9999

Note that you will need to use the os.Args variable in your code to access the user-specified command line arguments.

Running the tests

Unlike in previous projects, the tests for part B will not be open source. Instead, we have provided two binaries—ctest and mtest—for you to use to test your code. On Autolab, we will be testing you using these two binaries along with an additional stest binary.

To execute the tests, make sure your GOPATH is properly set and then execute them as follows (note that you for each binary, you can activate verbose-mode by specifying the -v flag). Make sure you compile your client, miner, and server programs using go install before running the tests!

# Run ctest on a Linux machine in non-verbose mode.
$GOPATH/src/github.com/cmu440/bitcoin/tests/ctest

When you run the tests, one of the first things you'll probably notice is that none of the logs you print in both the code you write for part A and part B will not appear. This is because our test binaries must capture the output of your programs in order to test that your request clients print the correct result message to standard output at the end of each test. An alternative to logging messages to standard output is to use a log.Logger and direct them to a file instead, as illustrated by the code below:

const (
    name = "log.txt"
    flag = os.O_RDWR | os.O_CREATE
    perm = os.FileMode(0666)
)

file, err := os.OpenFile(name, flag, perm)
if err != nil {
    return
}

LOGF := log.New(file, "", log.Lshortfile|log.Lmicroseconds)
LOGF.Println("Bees?!", "Beads.", "Gob's not on board.")

Don't forget to call file.Close() when you are done using it!

Submitting to Autolab

To submit your code to Autolab, create a cmu440.tar file containing your part A and part B implementation as follows:

cd p1/src/github.com/
tar -cvf cmu440.tar cmu440/

Miscellaneous

Reading the API Documentation

Before you begin the project, you should read and understand all of the starter code we provide. To make this experience a little less traumatic (we know, it's a lot :P), fire up a web server and read the documentation in a browser by executing the following command:

godoc -http=:6060 &

Then, navigate to localhost:6060/pkg/github.com/cmu440 in a browser. Note that you can execute this command from anywhere in your system (assuming your GOPATH is pointing to the project's root p1/ directory).