Java FAQ: Top Questions

The Java Memory Model (JMM) defines how threads interact with memory, ensuring consistent behavior in concurrent programs, specified in the Java Language Specification.

• Happens-Before: Guarantees visibility of memory operations (e.g., volatile , synchronized ).
• Thread-Local Memory: Each thread may cache variables; JMM ensures synchronization.
• Visibility: Ensures changes by one thread are visible to others (e.g., via volatile ).
• Atomicity: Defines which operations are indivisible (e.g., long writes may not be atomic).
• Use Case: Writing correct, thread-safe code.