CS 0449 – pthreads Lab

Due: Friday, August 3, 2012 by Midnight

Make a program with two threads. Note: Remember to compile your program with the -pthread option.

In the first thread, make an infinite loop that does:

printf(“Hello from thread 1 - A\n”);

printf(“Hello from thread 1 - B\n”);

In the second thread, do an infinite loop that does:

printf(“Hello from thread 2 - A\n”);

printf(“Hello from thread 2 - B\n”);

Run the program, and eventually stop it with CTRL+C. The time between thread switches is called a quantum.  

1.) Does the quantum seem long or short?

2.) What happens if you insert a pthread_yield() into each loop between the two printf calls?

Now, put a mutex around the two prints and the yield in each thread.

3.) What is the output like?

Submission

You need to submit:

• Your final source code for the mutex version
• A README text file that contains your answers to the three questions.

Make a tar.gz file as in the first assignment, named USERNAME-lab6.tar.gz

Copy it to ~jrmst106/submit/449/ by the deadline for credit.