Of concurrency and other demons

Talk about concurrency.
Initially presented at DawsCon with Hillmer Chona

Transcript

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2. ➔ Software developer - Team lead
   ➔ Java Champion
   ➔ Medellin Java Users Group Leader
   ➔ hibernate/hibernate-validator Contributor
   ➔ Duke’s Choice Award Winner
   ➔ Eclipse Collections contributor
   

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3. ➔ Professional with 10+ years
   ➔ Principal Software Engineer - NY
   ➔ NYJavaSIG Leader
   ➔ graciano.dev
   ➔ Twitter: @rodrigograciano
   

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4. ●
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5. ● Concurrency when we have many task, largely independent, and we use the same
   resource to do them at a time
   ● Parallelism is when we want to do one task, and we split up in multiple subtasks
   

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6. A Thread is an independent path of execution that allows a program to operate more efficiently by doing
   multiple things at the same time.
   Threads can be used to perform complicated tasks in the background without interrupting the main program.
   

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7. ● Synchronous: when we wait to finish a task before moving to the next one
   ● Asynchronous: when we move to another task before it finishes
   

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8. ●
   Thread t = new Thread( ()-> this.doSomething( thing ));
   t.start();
   ●
   ExecutorService executor = Executors.newFixedThreadPool( 10 );
   Future> future = executor.submit( ()-> this.doSomething( thing ));
   ●
   CompletableFuture.runAsync( ()-> this.doSomething( thing ));
   ●
   Thread.builder().virtual().name("name").task(() -> this.doSomething( thing )).start();
   

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11. Stream API CompletableFuture
    Creation Chained operations Return
    forEach runAsync thenAccept / thenRun void
    map supplyAsync thenApply CompletableFuture
    

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13. CompletableFuture::runAsync (Runnable runnable)
    CompletableFuture::supplyAsync (Supplier supplier)
    CompletableFuture::runAsync (Runnable runnable, Executor executor)
    CompletableFuture::supplyAsync (Supplier supplier, Executor executor)
    

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14. static ExecutorService newCachedThreadPool()
    static ExecutorService newFixedThreadPool (int nThreads)
    static ScheduledExecutorService newScheduledThreadPool (int corePoolSize)
    static ExecutorService newSingleThreadExecutor()
    static ScheduledExecutorService newSingleThreadScheduledExecutor()
    static ExecutorService newWorkStealingPool()
    

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15. T::get () throws InterruptedException , ExecutionException
    T::get (long timeout, TimeUnit unit) throws InterruptedException ,
    ExecutionException , TimeoutException
    T::getNow (T valueIfAbsent)
    T::join()
    

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