23.1. The Java Memory Model (JMM)

Try these first

1. 1.

   What role does the Java Memory Model play in multithreading?

   Hint

   Consider the term 'multithreading' and what is required for communication.

2. 2.

   Explain what visibility means in the context of threading.

   Hint

   Think about what happens when one thread changes a variable.

3. 3.

   What does the Java Memory Model define?

   • How threads communicate through shared memory
   • How to optimize CPU usage
   • How to write single-threaded applications

   Hint

   Think about the core goals of the memory model in multithreading.

4. 4.

   True or False: The Happens-Before relationship guarantees that one thread's changes are immediately visible to all other threads.

   • True
   • False

   Hint

   Consider the implications of memory coherence.

5. 5.

   Given a scenario where Thread A updates a shared counter and Thread B reads it without synchronization, what issues could arise in terms of visibility?

   Hint

   Consider how threads interact with shared data.

6. 6.

   Propose a solution to ensure that both atomicity and visibility are maintained when multiple threads are accessing a shared resource.

   Hint

   Think about Java's built-in mechanisms for thread safety.