lmajano / to-the-future-with-cbFutures

A session on learning about ColdBox 6 Futures and Async Programming

To The Future With cbFutures 🚀

by Luis Majano - Ortus Solutions

In this session we will explore the asynchronous and parallel programming constructs built into ColdBox. Java has supported a robust and functional approach to asynchronous programming since JDK8 and now it is available to us all in the Coldfusion (CFML) ⚡ World! To the future!

• 📧 Email: [e-mail]
• 🐦 Twitter: @lmajano @ortussolutions
• 🔗 Site: www.ortussolutions.com
• 🔗 Code: https://github.com/lmajano/to-the-future-with-cbFutures

📅 Agenda

• [] The NB (non-blocking) movement

  • [] Has made NodeJS shine, but other languages support this as well.
  • [] Movement to more async/parallel computations
  • [] Overall movement to computations

• [] Lessons from Callbacks

  • [] Also refered to as Callback hell 🔥
    • Example: Callback Hell
  • [] Can make developers cry 😢
  • [] Never ending nesting collection of closures/functions 🕷️
  • [] Callbacks could be called multiple times by the other library.
  • [] Who has been there before? Don't lie! 🤥

• [] Movement to promises

  • [] JavaScript has made this very popular
  • [] To get some sanity back into to development from call back hellfire 🔥
  • [] What is a promise?
  • [] Can have 3 different states:
    • Resolve : When completed
    • Reject : Error or something else
    • Pending : Not executing just yet
  • [] Cancel and Resolve them programmatically
  • [] Two channels of communication Promises Track
    • Data
    • Error

• [] What about ColdFusion?

  • [] cfthread, right?? right? right? 🤔
    • [] Great BUUUUUUT for very very very very basic threading
    • [] Easy, but plagued with issues, which makes developers ALSO cry :😢
      • [] No way to choose where it runs (thread pool)
      • [] No concept of returning data, it's up to you to monitor/track data
      • [] Hard to manage them (cancel, monitor, pause), you are on your own buddy!
      • [] No functional approaches
      • [] Managing multiple threads and joining can be cumbersome and horrible
      • [] Example: Interceptor State Manager - Process Async All
  • [] Nothing existed until ACF2018/Lucee 5.3 => runAsync()
    • [] A step up, but not a big step
    • [] Still Many Issues:
      • [] Backed by a custom wrapper to java.util.concurrent.Future, jdk6
      • [] Simplistic error handler with no way to recover or continue executing pipelines after an exception. Concept of two tracks is broken!
      • [] No way to choose or reuse the executor to run the sub-sequent then() operations. Lucee actually creates a new singleThreadExecutor() for EVERY then() operation.
      • [] No way to operate on multiple futures at once
      • [] No way to combine/compose futures
      • [] Only works with closures, does not work on actually calling component methods
  • [] 🤢 We have two approaches to threading which are extremely simplistic and not powerful at all.

• [] What about Java?

  • [] JDK 8 Introduced CompletableFutures, CompletionStages, Executors, Lambdas and much more.
  • [] 🦄 Java CompletableFutures are like JavaScript Promises, but you know Java devs, over complicate things, even names!
  • [] We have ported the majority of this functionality to CFML: ColdBox Futures
    • ColdBox, WireBox, CacheBox and LogBox

• [] What is a ColdBox Future?

  • [] Similar to JavaScript Promises but in CF backed by CompletableFuture Java API
  • [] Adapted for our dynamic language => many enhancements
  • [] AsyncManager class in charge of all async capabilities
    • [] Standalone: create an instance as a singleton
    • [] ColdBox: async() or inject:AsyncManager@coldbox
    • [] Functions:
      • Create Futures
      • Create/Manage Executors
      • Create/Manage Schedule Tasks
      • Utility Functions
      • https://s3.amazonaws.com/apidocs.ortussolutions.com/coldbox/6.8.1/coldbox/system/async/AsyncManager.html
  • [] Create the Future!
    • [] cbFutures Stages
    • [] Create a future
    • [] Thread of execution
    • [] Changing the pool
      • [] Register many different types of executors/pool
        • [] Fixed : Control the amount of threads, cpu intensive, io intensive
        • [] Single : A processing queue FIFO
        • [] Cached : Ever expanding demand queue
        • [] Scheduled : Scheduled Tasks

• [] 🎩 Magical Pipelines

  • [] Java API: thenApply(), thenAccept(), thenRun(), why?
    • 
  • [] CF API: then() and thenRun() (Easier + Dynamic API)
    • [] Curiosity: CompletableFutures never end! This is So Ironic! Sharknado! 🦈
  • Data Transformations
  • Dealing with Exceptions
  • Dealing with Timeouts
    • Success on timeout
    • Exception on timeout
  • Checking status

• [] Working with multiple futures

  • Racing Futures
  • All Futures
  • All futures Modified

• [] Extra Credit: Schedule Tasks!