Scala example source code file (TaskSupport.scala)

This example Scala source code file (TaskSupport.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Scala source code examples by using tags.

All credit for the original source code belongs to scala-lang.org; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Scala tags/keywords

adaptiveworkstealingforkjointasks, concurrent, executioncontexttasks, executioncontexttasksupport, forkjoin, forkjoinpool, forkjointasksupport, tasks, tasksupport, threadpoolexecutor, threadpooltasksupport, use

The TaskSupport.scala Scala example source code

/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2003-2013, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */

package scala
package collection.parallel

import java.util.concurrent.ThreadPoolExecutor
import scala.concurrent.forkjoin.ForkJoinPool
import scala.concurrent.ExecutionContext

/** A trait implementing the scheduling of a parallel collection operation.
 *
 *  Parallel collections are modular in the way operations are scheduled. Each
 *  parallel collection is parametrized with a task support object which is
 *  responsible for scheduling and load-balancing tasks to processors.
 *
 *  A task support object can be changed in a parallel collection after it has
 *  been created, but only during a quiescent period, i.e. while there are no
 *  concurrent invocations to parallel collection methods.
 *
 *  There are currently a few task support implementations available for
 *  parallel collections. The [[scala.collection.parallel.ForkJoinTaskSupport]]
 *  uses a fork-join pool internally.
 *
 *  The [[scala.collection.parallel.ExecutionContextTaskSupport]] uses the
 *  default execution context implementation found in scala.concurrent, and it
 *  reuses the thread pool used in scala.concurrent.
 *
 *  The execution context task support is set to each parallel collection by
 *  default, so parallel collections reuse the same fork-join pool as the
 *  future API.
 *
 *  Here is a way to change the task support of a parallel collection:
 *
 *  {{{
 *  import scala.collection.parallel._
 *  val pc = mutable.ParArray(1, 2, 3)
 *  pc.tasksupport = new ForkJoinTaskSupport(
 *    new scala.concurrent.forkjoin.ForkJoinPool(2))
 *  }}}
 *
 *  @see [[http://docs.scala-lang.org/overviews/parallel-collections/configuration.html Configuring Parallel Collections]] section
 *    on the parallel collection's guide for more information.
 */
trait TaskSupport extends Tasks

/** A task support that uses a fork join pool to schedule tasks.
 *
 *  @see [[scala.collection.parallel.TaskSupport]] for more information.
 */
class ForkJoinTaskSupport(val environment: ForkJoinPool = ForkJoinTasks.defaultForkJoinPool)
extends TaskSupport with AdaptiveWorkStealingForkJoinTasks

/** A task support that uses a thread pool executor to schedule tasks.
 *
 *  @see [[scala.collection.parallel.TaskSupport]] for more information.
 */
@deprecated("Use `ForkJoinTaskSupport` instead.", "2.11.0")
class ThreadPoolTaskSupport(val environment: ThreadPoolExecutor = ThreadPoolTasks.defaultThreadPool)
extends TaskSupport with AdaptiveWorkStealingThreadPoolTasks

/** A task support that uses an execution context to schedule tasks.
 *
 *  It can be used with the default execution context implementation in the
 *  `scala.concurrent` package. It internally forwards the call to either a
 *  forkjoin based task support or a thread pool executor one, depending on
 *  what the execution context uses.
 *
 *  By default, parallel collections are parametrized with this task support
 *  object, so parallel collections share the same execution context backend
 *  as the rest of the `scala.concurrent` package.
 *
 *  @see [[scala.collection.parallel.TaskSupport]] for more information.
 */
class ExecutionContextTaskSupport(val environment: ExecutionContext = scala.concurrent.ExecutionContext.global)
extends TaskSupport with ExecutionContextTasks