Common Concurrency Issues and Solutions in Java

Common Concurrency Issues

JVM enables multi-threads in Java application. There are common problem for Multi-Threads such as Race Condition, Deadlocks, Starvation.

Race Conditions

Example: different threads try to read and write value to same variable. The value depends on which thread writes the value to the variable.

Deadlocks

Example: One thread locks the resource and another thread keeps waiting on it.

Starvation

Example: One greedy thread constantly acquiring the resource resulting anther thread being starvation or no progress.

Java Solutions

Java provides several solutions to handle concurrency issues such as Thread-safe objects, Thread-safe collection, Synchronisation, Atomic Variables, volatile and other High-Level Concurrency API.

Thread-safe objects

Examples: Immutable Objects

Thread-safe Collections

Examples: CopyOnWriteArrayList, ConcurrentHashMap

Synchronisation

Examples: synchronized key word

Atomic Variables

Examples: AtomicInteger , AtomicLong , AtomicReference

These variables provide atomic operation which complete operation in a single step and compare-and-swap (CAS) to ensure data integrity.