Java Concurrency Tools for the JVM. This project aims to offer some concurrent data structures currently missing from the JDK:

• SPSC/MPSC/SPMC/MPMC variations for concurrent queues:
  • SPSC - Single Producer Single Consumer (Wait Free, bounded and unbounded)
  • MPSC - Multi Producer Single Consumer (Lock less, bounded and unbounded)
  • SPMC - Single Producer Multi Consumer (Lock less, bounded)
  • MPMC - Multi Producer Multi Consumer (Lock less, bounded)
• An expanded queue interface (MessagePassingQueue):
  • relaxedOffer/Peek/Poll: trade off conflated guarantee on full/empty queue state with improved performance.
  • drain/fill: batch read and write methods for increased throughput and reduced contention

There's more to come and contributions/suggestions are most welcome. JCTools offers excellent performance at a reasonable price (FREE! under the Apache 2.0 License). It's stable and in use by such distiguished frameworks as Netty, RxJava and others. JCTools is also used by commercial products to great result.

Add the latest version as a dependency using Maven:

        <dependency>
            <groupId>org.jctools</groupId>
            <artifactId>jctools-core</artifactId>
            <version>1.1</version>
        </dependency>

Or use the awesome, built from source, https://jitpack.io/ version, you'll need to add the Jitpack repository:

        <repository>
          <id>jitpack.io</id>
           <url>https://jitpack.io</url>
        </repository>

And setup the following dependency:

        <dependency>
            <groupId>com.github.JCTools.JCTools</groupId>
            <artifactId>jctools-core</artifactId>
            <version>1.1</version>
        </dependency>

You can also depepnd on latest snapshot from this repository (live on the edge) by setting the version to '1.2-SNAPSHOT'.

JCTools is maven built and requires an existing Maven installation and JDK8 (only for building, runtime is 1.6 compliant).

With 'MAVEN_HOME/bin' on the path and JDK8 set to your 'JAVA_HOME' you should be able to run "mvn install" from this directory.

JCTools is benchmarked using both JMH benchmarks and handrolled harnesses. The benchmarks and related instructions can be found in the jctools-benchmarks module README. Go wild and please let us know how it did on your hardware.

Experimental work is available under the jctools-experimental module. Most of the stuff is developed with an eye to eventually porting it to the core where it will be stabilized and released, but some implementations are kept purely for reference and some may never graduate. Beware the Jabberwock my child.