WARNING: A user recently discovered that a massive memory leak exists when running this on CF9. Therefore, it is not safe to use this library on Adobe ColdFusion 9. The problem is not in the library but in the interaction between Java executors and ColdFusion. I will attempt to work with Adobe to identify a fix. ColdFusion 10 is unaffected and behaves as expected.
CFConcurrent simplifies the use of the Java Concurrency Framework (java tutorial | javadoc) in ColdFusion applications.
CFConcurrent runs on CF10+.
Although CFThread is suitable for management-free fire-and-forget concurrency, robust production applications require higher-level abstractions and a greater degree of control. The Java Concurrency Framework (JCF) provides such improvements, and you can take advantage of it using 100% CFML.
You create CFCs that act as "tasks" that return results. You submit those tasks to the JCF for execution. You can then retrieve the execution results immediately when they are available, or you can create a periodic "polling" task which processes the completed results.
In addition, you can easily create cancelable, pausable scheduled tasks directly in your code (think: heartbeats, daemons), freeing you from the 1-minute limitation of ColdFusion's scheduled task implementation.
CFConcurrent's goals are:
- Simplify Java object and proxy creation
- Expose common patterns as generic services
- Expose extensible base components
- Do not over-reach
- Limit protectionist tendencies
CFConcurrent is not a "wrapper" library, nor does it hide the Java Concurrency Framework from you.
I started writing concurrent programs in Java in 2004. This library represents what I wish I had in ColdFusion since learning to write concurrent programs.
For CF developers, Concurrency trends thusly: 1) Lob it into CFThread and hope it works. 2) OMG it's hard to do correctly. Let's eat cake. 3) Spend an inordinate amount of time with locks, app and server-scoped based data sharing schemes, and brittle thread-cancelling mechanisms.
I want this library to expose safe, correct concurrency abstractions that enable high-quality concurrent programming in ColdFusion applications.
You want to see code. CFConcurrent ships with running examples and a suite of MXUnit tests. Docs are in the wiki: https://github.com/marcesher/cfconcurrent/wiki.
CFConcurrent owes a great deal to Mark Mandel and JavaLoader. While CFConcurrent uses native Java proxy object creation on CF10, it requires JavaLoader on CF9. This project would not be possible today without JavaLoader.
Doug Lea began util.concurrent in 1998, just a few years after the release of both Java and CF version 1. In 2004, with Java 5, util.concurrent was brought into the JDK as an official package, named java.util.concurrent. Thus, 3 years before ColdFusion received multithreading capabilities via CFThread (in CF8), Java provided a vastly superior approach to concurrency. Unfortunately, CF developers could not take advantage of java.util.concurrent because of the inability to pass ColdFusion Component (CFC) instances to a Java library.
This changed in 2011, when Mark Mandel tweaked the Java proxy object creation facility available in JavaLoader to enable CFC instances to be passed to invocation methods in the Java concurrency framework. With this ability, "concurrency as it should be" is now possible in ColdFusion.
ForkJoinPool -- I'll be adding a ForkJoinPool service along with examples.
Post issues to https://github.com/marcesher/cfconcurrent/issues. Pull requests should have accompanying MXUnit tests. If it's not tested, it's not accepted.
CFConcurrent is published under the MIT license.