This repository contains multiple implementations of a thread-safe counter, accompanied by a complete benchmarking suite to compare their performance. It was created to test modern concurrency features in Java and compare different concurrent counter strategies.
The different counter implementations include:
- Simple (without synchronization)
- Java Synchronized
- Unsafe
- VarHandle
- ReentrantLock
- AtomicInteger
- Java SDK version 17
- IntelliJ IDEA
- Maven (for managing dependencies and build configuration)
Clone the repository and open it in IntelliJ IDEA. The main class CounterTest runs and measures the performance of all counter implementations under varied concurrent load.
The counter implementations show different results when run on CounterTest. Here are the results:
Final Counter Value: 196699615
Expected Counter Value: 200000000
Time Taken: 0.028589333 seconds
Final Counter Value: 200000000
Expected Counter Value: 200000000
Time Taken: 19.807858875 seconds
Final Counter Value: 200000000
Expected Counter Value: 200000000
Time Taken: 12.420408125 seconds
Final Counter Value: 200000000
Expected Counter Value: 200000000
Time Taken: 12.605674958 seconds
Final Counter Value: 200000000
Expected Counter Value: 200000000
Time Taken: 4.110033459 seconds
Final Counter Value: 200000000
Expected Counter Value: 200000000
Time Taken: 13.654771916 seconds
Please note that these results may vary based on the system and the current CPU workload.
JMH (Java Microbenchmark Harness) is used in creating benchmarks. Multiple threads try to increment each counter implementation concurrently. This provides a realistic gauge on the performance of each implementation under stress.
Just smile! :)
Pull requests for additional counter strategies or improved benchmarks are warmly welcome.