# Interface WorkerExecutor

@ServiceScope(org.gradle.internal.service.scopes.Scope.Project.class) public interface WorkerExecutor
Allows work to be submitted for asynchronous execution. This api allows for safe, concurrent execution of work items and enables:

- Parallel execution of work items within a single task
- Execution in isolated contexts such as an isolated classloader or even a separate process
- Safe execution of multiple tasks in parallel

Work should be submitted with a `WorkAction` class representing the implementation of the unit of work and an action to configure the parameters of the unit of work (via `WorkParameters`).

         workerExecutor.noIsolation().submit(MyWorkActionImpl.class) { MyWorkParameters parameters ->
             parameters.inputFile = project.file('foo')
             parameters.outputFile = project.layout.buildDirectory.file('bar')
         }

An instance of the executor can be injected into a task by annotating a public constructor or property getter method with `javax.inject.Inject`.

Since:
  3.5

- ## Method Summary

  Modifier and Type
  Method
  Description
  `void`
  `await()`
  Blocks until all work associated with the current build operation is complete.
  `WorkQueue`
  `classLoaderIsolation()`
  Creates a `WorkQueue` to submit work for asynchronous execution with an isolated classloader.
  `WorkQueue`
  `classLoaderIsolation(Action<? super ClassLoaderWorkerSpec> action)`
  Creates a `WorkQueue` to submit work for asynchronous execution with an isolated classloader and the requirements specified in the supplied `ClassLoaderWorkerSpec`.
  `WorkQueue`
  `noIsolation()`
  Creates a `WorkQueue` to submit work for asynchronous execution with no isolation.
  `WorkQueue`
  `noIsolation(Action<? super WorkerSpec> action)`
  Creates a `WorkQueue` to submit work for asynchronous execution with no isolation and the requirements specified in the supplied `WorkerSpec`.
  `WorkQueue`
  `processIsolation()`
  Creates a `WorkQueue` to submit work for asynchronous execution in a daemon process.
  `WorkQueue`
  `processIsolation(Action<? super ProcessWorkerSpec> action)`
  Creates a `WorkQueue` to submit work for asynchronous execution in a daemon process.

- ## Method Details

  - ### noIsolation

    WorkQueue noIsolation()
    Creates a `WorkQueue` to submit work for asynchronous execution with no isolation.
    Since:
      5.6

  - ### classLoaderIsolation

    WorkQueue classLoaderIsolation()
    Creates a `WorkQueue` to submit work for asynchronous execution with an isolated classloader.
    Since:
      5.6

  - ### processIsolation

    WorkQueue processIsolation()
    Creates a `WorkQueue` to submit work for asynchronous execution in a daemon process. Work will execute in an idle daemon, if available. If no idle daemons are available, a new daemon will be started.
    Since:
      5.6

  - ### noIsolation

    WorkQueue noIsolation(Action<? super WorkerSpec> action)
    Creates a `WorkQueue` to submit work for asynchronous execution with no isolation and the requirements specified in the supplied `WorkerSpec`.
    Since:
      5.6

  - ### classLoaderIsolation

    WorkQueue classLoaderIsolation(Action<? super ClassLoaderWorkerSpec> action)
    Creates a `WorkQueue` to submit work for asynchronous execution with an isolated classloader and the requirements specified in the supplied `ClassLoaderWorkerSpec`.
    Since:
      5.6

  - ### processIsolation

    WorkQueue processIsolation(Action<? super ProcessWorkerSpec> action)
    Creates a `WorkQueue` to submit work for asynchronous execution in a daemon process. Work will execute in an idle daemon matching the requirements specified in the supplied `ProcessWorkerSpec`, if available. If no idle daemons are available, a new daemon will be started.
    Since:
      5.6

  - ### await

    void await() throws WorkerExecutionException
    Blocks until all work associated with the current build operation is complete. Note that when using this method inside a task action, it will block completion of the task action until all submitted work is complete. This means that other tasks from the same project cannot be run in parallel while the task action is still executing.
    Throws:
      `WorkerExecutionException` - when a failure occurs while executing the work.