23.3.1. Without Synchronization

Try these first

1. 1.

   What is the visibility problem in multithreading?

   Hint

   Think about how threads interact with shared resources.

2. 2.

   What does 'flag' generally signify in concurrent programming?

   Hint

   Consider its boolean nature.

3. 3.

   What main issue does the example in the section illustrate?

   • Thread safety
   • Visibility problems
   • Compiler optimizations

   Hint

   Consider what happens when changes are not propagated.

4. 4.

   True or False: A spin loop will always see the updated value of a shared variable.

   • True
   • False

   Hint

   Reflect on how threads read shared variables.

5. 5.

   Given a scenario with multiple threads reading and writing to a shared boolean flag, outline a comprehensive strategy to ensure proper visibility.

   Hint

   Consider how Java's memory model dictates visibility requirements.

6. 6.

   Analyze the effect of introducing sleep before setting the flag in the primary thread. Will it help in achieving visibility?

   Hint

   Think about what guarantees visibility entails.