Par-prog_2019-03-19_ TL.pdf

The exam is for the Principles of Concurrent Programming course at Chalmers University, supervised by Sandro Stucki, with an examiner K. V. S. Prasad. The exam has a maximum score of 70 points, with grades ranging from 3 to 5. The material permitted during the exam includes two textbooks, four sheets of A4 paper with notes, and an English dictionary.

The exam consists of five questions, with the first question focusing on a concurrent counter array implemented in Java. The question has five parts:
- Part a asks about the maximum number of threads that can call the increment method concurrently without blocking and the maximum number of counters that could be safely incremented concurrently.
- Part b requires adjusting the implementation to allow maximal concurrent access using a lock-based solution.
- Part c explains the type of overhead the lock-based solution may suffer from and compares the cost of locking to incrementing the counter.
- Part d asks to adjust the implementation to remove locking overhead while allowing maximal concurrent access.
- Part e compares the performance of the solutions from Part b and Part d.

The second question involves barrier synchronization for two threads using semaphores, with an incomplete state transition table provided. The table covers statements that access the shared variable barrier and the ends of the threads.

The exam results will be available in Ladok within 15 working days after the exam date. Instructions and rules for the exam include writing clear and legible answers, justifying answers, and stating assumptions. Each question should be answered on a new page, and time should be allocated accordingly to the points each question carries.