23.4.3. Memory Effects of Synchronization

Try these first

1. 1.

   What happens when a thread enters a synchronized block?

   Hint

   Think about how threads see updates.

2. 2.

   Define a memory consistency error.

   Hint

   Consider the effects of improper synchronization.

3. 3.

   What happens when a thread enters a synchronized block in Java?

   • It flushes changes to working memory.
   • It flushes changes to main memory.
   • It locks all threads.

   Hint

   Consider why visibility is important.

4. 4.

   True or False: Exiting a synchronized block pushes changes to working memory.

   • True
   • False

   Hint

   Think about where changes need to be visible.

5. 5.

   Suppose you have two threads that update a shared variable without synchronization. Explain potential outcomes.

   Hint

   Think about race conditions and visibility.

6. 6.

   Write a multithreaded Java program that demonstrates the correct use of synchronization and discuss the importance of memory effects.

   Hint

   Consider what happens when threads enter and exit these blocks.