so898 / concurrency-java

Dispatch queues (akin to Grand Central Dispatch), Promises and Cocoa Operations implemented in Java

Advanced Java Concurrency Primitives

Dispatch Queues

Features

• Functionally equivalent interface to GCD
• Global Dispatch Queues (High, Medium, Low, Main & UI)
• Concurrent Dispatch Queues
• Serial Dispatch Queues
• Dispatch Queue Groups
• Dispatch Barriers
• Android Support (currently requires retrolambda)

Implementation

All dispatch queues are implemented in 100% pure java using the standard Java 7 concurrency primitives. Global & Concurrent dispatch queues are implemented using a common priority based thread pool. Serial dispatch queues are implemented on top of an existing dispatch queue.

Availability

Maven (snapshots in oss.jfrog.org & oss.sonatype.org)

  <dependency>
      <groupId>io.retxt.concurrency</groupId>
      <artifactId>dispatch</artifactId>
      <version>${version}</version>
  </dependency>
  <!-- Optional Android support -->
  <dependency>
      <groupId>io.retxt.concurrency</groupId>
      <artifactId>dispatch-android</artifactId>
      <version>${version}</version>
  </dependency>

Gradle

io.retxt.concurrency:dispatch:${version}
// Optional Android support
io.retxt.concurrency:dispatch-android:${version}

Promises

Features

• Similar interface and implementation to PromiseKit
• Defaults to executing on main queue but easily redirectable to a specific or background queue

Implementation

Promises are implemented via the dispatch queues and they are 100% pure Java and provide tight integration with Operations as well.

Availability

Maven (snapshots in oss.jfrog.org & oss.sonatype.org)

  <dependency>
      <groupId>io.retxt.concurrency</groupId>
      <artifactId>promise</artifactId>
      <version>${version}</version>
  </dependency>

Gradle

io.retxt.concurrency:promise:${version}

Operations & Operation Queues

Features

• General Operations
  • Same interface as Cocoa NSOperation & NSOperationQueue
  • Dependencies
  • Cancellation
• Advanced Operations
  • Very similar to those described in WWDC 2015 - Session #226
  • Conditions - Required to bet met before operation can be executed
    • Examples
      • Mutual Exclusion - Ensure only one instance of operations with this condition can execute simulataneously
      • No Cancelled Dependencies - Ensure operation executes only if no dependencies were cancelled
      • Delay - Delay start of operation for a specific time period
    • Easy creation of new conditions such as network reachability or UI modal exclusion
  • Finish & cancel with errors

Implementation

All Operations and AdvancedOperations are implemented via the dispatch queues and therefore are 100% pure Java and provide tight integration with Promises as well.

Availability

Maven (snapshots in oss.jfrog.org & oss.sonatype.org)

  <dependency>
      <groupId>io.retxt.concurrency</groupId>
      <artifactId>operations</artifactId>
      <version>${version}</version>
  </dependency>

Gradle

io.retxt.concurrency:operations:${version}