Java Concurrency examples

Personal examples and investigation code on Java concurrency: hand-rolled primitives (a blocking queue, a bounded set, an atomic double, a tiny executor) and classic coordination problems (producer/consumer, ping-pong, latches).

Requirements

• JDK 25 (see .sdkmanrc — sdk env picks it up automatically)
• Gradle is provided via the wrapper; no local install needed.

Build & test

./gradlew build      # compile + run the test suite
./gradlew test       # tests only

Dependency versions are centralized in gradle/libs.versions.toml.

Running an example

Each example under src/main/java/.../primitives and .../primitives/other has its own main method. Run one from your IDE, or from the command line after ./gradlew build, e.g.:

java -cp build/classes/java/main dev.astamur.concurrency.primitives.other.PingPongWithQueue

(Examples that use logging also need SLF4J/Logback on the classpath; running from the IDE is the simplest way to get the full runtime classpath.)

Layout

• primitives/structure — reusable building blocks: SimpleBlockingQueue, SimpleBlockingQueueWithLock, BoundedHashSet, AtomicDouble, SimpleExecutor
• primitives/other — runnable demos: producer/consumer, ping-pong, CountDownLatch
• src/test — JUnit 5 tests for the reusable structures