Lecture 20

Learning objectives

After this class, you should be able to:

1. Explain OpenMP's programming model.
2. Use the following OpenMP features to write parallel code: parallel and critical directives, omp_get_thread_num, and omp_get_num_threads.

Reading assignment

1. Section 5.1 - 5.3.
2. Lecture 20 slides.
3. Lecture 20 example code.
4. OpenMP tutorial.
5. Page 224.

Exercises and review questions

• Questions on current lecture's material
  1. Output the result of omp_get_num_threads in parallel and sequential regions. What difference do you see?
  2. Change the hello example so that the number of threads is set using omp_set_num_threads. Use omp_get_num_procs to determine a suitable number of threads.

• Questions on next lecture's material
  1. Give one OpenMP directive that helps with work sharing.