1. Debugging In a Multi- Threads Program

2. Contents 1 2 3 4 Advantages Of Multithreaded Programs Characteristics Of Sequential and Multithreaded Programs Why More Bugs And How to Prevent them How To Debug

3. 1 Advantages Of Multithreaded Programs

4. Raise clock rate? “parallelism” ILP, Instruction Level Parallelism TLP, Thread Level Parallelism

5. 2 Characteristics Of Sequential and Multithreaded Programs

6. Comparison

7. Sample Behavior is nondeterministic

8. 3 Why More Bugs And How to Prevent them

9. Where Is Bug 1 2 3 4 “ Out-Of-Order ”

10. Out-Of-Order sleep() Latch CyclicBarrier CountDownLatch latch = new CountDownLatch(3); countDown() await() CyclicBarrier cyclicBarrier = new CyclicBarrier(3); cyclicBarrier.await(); Producer-Consumer Mode wait() 、 notify() 、 notifyAll()

11. Where Is Bug 1 2 3 4 Synchronization

12. Shared Memory Model Easy to understand Memory coherence is managed by the operating system

13. Synchronization synchronized Destroy parallelism

14. Where Is Bug 1 2 3 4 Deadlock Other

15. 4 How To Debug

16. 1 breakpoint 2 3 logJPDA JDI ENTER TEXT