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trait SchedulerService extends Scheduler

A Scheduler type that provides methods for managing termination.

A SchedulerService can be shut down, which will cause it to reject new tasks. The shutdown method allows previously submitted tasks to execute before terminating. The awaitTermination method allows waiting on all active tasks to finish.

Upon termination, an executor has no tasks actively executing, no tasks awaiting execution, and no new tasks can be submitted. An unused SchedulerService should be shut down to allow reclamation of its resources.

Source
SchedulerService.scala
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  1. SchedulerService
  2. Scheduler
  3. Executor
  4. UncaughtExceptionReporter
  5. Serializable
  6. ExecutionContext
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Abstract Value Members

  1. abstract def awaitTermination(timeout: Long, unit: TimeUnit, awaitOn: ExecutionContext): Future[Boolean]

    Returns a Future that will be complete when all tasks have completed execution after a shutdown request, or the timeout occurs, or the thread awaiting the shutdown is interrupted, whichever happens first.

    Returns a Future that will be complete when all tasks have completed execution after a shutdown request, or the timeout occurs, or the thread awaiting the shutdown is interrupted, whichever happens first.

    NOTE that this method does not block the current thread, unlike the similarly named method in Java's ExecutionService. This is because Monix has a strict non-blocking policy, due to the fact that other platforms like Javascript cannot block threads.

    Because of the non-blocking requirement, this method returns a Future result. And on top of the JVM in order to block on such a result, you can just use Scala's Await.result:

    import scala.concurrent.Await
    import scala.concurrent.duration._
    import monix.execution.Scheduler.global
    
    val wasTerminated =
      Await.result(service.awaitTermination(30.seconds, global), Duration.Inf)

    Given the asynchronous execution requirement, the awaitOn parameter is a Scheduler that's going to be used for terminating this service and completing our Future. Obviously we cannot reuse this service for awaiting on termination, but Monix's Scheduler.global can always be used for this.

    timeout

    the maximum time to wait

    unit

    the time unit of the timeout argument

    awaitOn

    the ExecutionContext used for awaiting the shutdown

    returns

    a Future signaling true if this scheduler terminated or false if the timeout elapsed before termination

  2. abstract def clockMonotonic(unit: TimeUnit): Long

    Returns a monotonic clock measurement, if supported by the underlying platform.

    Returns a monotonic clock measurement, if supported by the underlying platform.

    This is the pure equivalent of Java's System.nanoTime, or of CLOCK_MONOTONIC from Linux's clock_gettime().

    timer.clockMonotonic(NANOSECONDS)

    The returned value can have nanoseconds resolution and represents the number of time units elapsed since some fixed but arbitrary origin time. Usually this is the Unix epoch, but that's not a guarantee, as due to the limits of Long this will overflow in the future (263 is about 292 years in nanoseconds) and the implementation reserves the right to change the origin.

    The return value should not be considered related to wall-clock time, the primary use-case being to take time measurements and compute differences between such values, for example in order to measure the time it took to execute a task.

    As a matter of implementation detail, Monix's Scheduler implementations use System.nanoTime and the JVM will use CLOCK_MONOTONIC when available, instead of CLOCK_REALTIME (see clock_gettime() on Linux) and it is up to the underlying platform to implement it correctly.

    And be warned, there are platforms that don't have a correct implementation of CLOCK_MONOTONIC. For example at the moment of writing there is no standard way for such a clock on top of JavaScript and the situation isn't so clear cut for the JVM either, see:

    The JVM tries to do the right thing and at worst the resolution and behavior will be that of System.currentTimeMillis.

    The recommendation is to use this monotonic clock when doing measurements of execution time, or if you value monotonically increasing values more than a correspondence to wall-time, or otherwise prefer clockRealTime.

    Definition Classes
    Scheduler
  3. abstract def clockRealTime(unit: TimeUnit): Long

    Returns the current time, as a Unix timestamp (number of time units since the Unix epoch).

    Returns the current time, as a Unix timestamp (number of time units since the Unix epoch).

    This is the equivalent of Java's System.currentTimeMillis, or of CLOCK_REALTIME from Linux's clock_gettime().

    The provided TimeUnit determines the time unit of the output, its precision, but not necessarily its resolution, which is implementation dependent. For example this will return the number of milliseconds since the epoch:

    import scala.concurrent.duration.MILLISECONDS
    
    scheduler.clockRealTime(MILLISECONDS)

    N.B. the resolution is limited by the underlying implementation and by the underlying CPU and OS. If the implementation uses System.currentTimeMillis, then it can't have a better resolution than 1 millisecond, plus depending on underlying runtime (e.g. Node.js) it might return multiples of 10 milliseconds or more.

    See clockMonotonic, for fetching a monotonic value that may be better suited for doing time measurements.

    Definition Classes
    Scheduler
  4. abstract def execute(command: Runnable): Unit

    Schedules the given command for execution at some time in the future.

    Schedules the given command for execution at some time in the future.

    The command may execute in a new thread, in a pooled thread, in the calling thread, basically at the discretion of the Scheduler implementation.

    Definition Classes
    Scheduler → Executor → ExecutionContext
  5. abstract def executionModel: ExecutionModel

    The ExecutionModel is a specification of how run-loops and producers should behave in regards to executing tasks either synchronously or asynchronously.

    The ExecutionModel is a specification of how run-loops and producers should behave in regards to executing tasks either synchronously or asynchronously.

    Definition Classes
    Scheduler
  6. abstract def isShutdown: Boolean

    Returns true if this scheduler has been shut down.

  7. abstract def isTerminated: Boolean

    Returns true if all tasks have completed following shut down.

    Returns true if all tasks have completed following shut down. Note that isTerminated is never true unless shutdown was called first.

  8. abstract def reportFailure(t: Throwable): Unit

    Reports that an asynchronous computation failed.

    Reports that an asynchronous computation failed.

    Definition Classes
    SchedulerUncaughtExceptionReporter → ExecutionContext
  9. abstract def scheduleAtFixedRate(initialDelay: Long, period: Long, unit: TimeUnit, r: Runnable): Cancelable

    Schedules a periodic task that becomes enabled first after the given initial delay, and subsequently with the given period.

    Schedules a periodic task that becomes enabled first after the given initial delay, and subsequently with the given period. Executions will commence after initialDelay then initialDelay + period, then initialDelay + 2 * period and so on.

    If any execution of the task encounters an exception, subsequent executions are suppressed. Otherwise, the task will only terminate via cancellation or termination of the scheduler. If any execution of this task takes longer than its period, then subsequent executions may start late, but will not concurrently execute.

    For example the following schedules a message to be printed to standard output approximately every 10 seconds with an initial delay of 5 seconds:

    val task = scheduler.scheduleAtFixedRate(5, 10, TimeUnit.SECONDS, new Runnable {
      def run() = print("Repeated message")
    })
    
    // later if you change your mind ...
    task.cancel()
    initialDelay

    is the time to wait until the first execution happens

    period

    is the time to wait between 2 successive executions of the task

    unit

    is the time unit used for the initialDelay and the period parameters

    r

    is the callback to be executed

    returns

    a cancelable that can be used to cancel the execution of this repeated task at any time.

    Definition Classes
    Scheduler
  10. abstract def scheduleOnce(initialDelay: Long, unit: TimeUnit, r: Runnable): Cancelable

    Schedules a task to run in the future, after initialDelay.

    Schedules a task to run in the future, after initialDelay.

    For example the following schedules a message to be printed to standard output after 5 minutes:

    val task = scheduler.scheduleOnce(5, TimeUnit.MINUTES, new Runnable {
      def run() = print("Hello, world!")
    })
    
    // later if you change your mind ...
    task.cancel()
    initialDelay

    is the time to wait until the execution happens

    unit

    is the time unit used for initialDelay

    r

    is the callback to be executed

    returns

    a Cancelable that can be used to cancel the created task before execution.

    Definition Classes
    Scheduler
  11. abstract def scheduleWithFixedDelay(initialDelay: Long, delay: Long, unit: TimeUnit, r: Runnable): Cancelable

    Schedules for execution a periodic task that is first executed after the given initial delay and subsequently with the given delay between the termination of one execution and the commencement of the next.

    Schedules for execution a periodic task that is first executed after the given initial delay and subsequently with the given delay between the termination of one execution and the commencement of the next.

    For example the following schedules a message to be printed to standard output every 10 seconds with an initial delay of 5 seconds:

    val task = s.scheduleWithFixedDelay(5, 10, TimeUnit.SECONDS, new Runnable {
      def run() = print("Repeated message")
    })
    
    // later if you change your mind ...
    task.cancel()
    initialDelay

    is the time to wait until the first execution happens

    delay

    is the time to wait between 2 successive executions of the task

    unit

    is the time unit used for the initialDelay and the delay parameters

    r

    is the callback to be executed

    returns

    a cancelable that can be used to cancel the execution of this repeated task at any time.

    Definition Classes
    Scheduler
  12. abstract def shutdown(): Unit

    Initiates an orderly shutdown in which previously submitted tasks are executed, but no new tasks will be accepted.

    Initiates an orderly shutdown in which previously submitted tasks are executed, but no new tasks will be accepted.

    This method does not wait for previously submitted tasks to complete execution. Use awaitTermination to do that.

  13. abstract def withExecutionModel(em: ExecutionModel): SchedulerService

    Given a function that will receive the underlying ExecutionModel, returns a new Scheduler reference, based on the source, that exposes the transformed ExecutionModel when queried by means of the executionModel property.

    Given a function that will receive the underlying ExecutionModel, returns a new Scheduler reference, based on the source, that exposes the transformed ExecutionModel when queried by means of the executionModel property.

    This method enables reusing global scheduler references in a local scope, but with a slightly modified execution model to inject.

    The contract of this method (things you can rely on):

    1. the source Scheduler must not be modified in any way
    2. the implementation should wrap the source efficiently, such that the result mirrors the source Scheduler in every way except for the execution model

    Sample:

    import monix.execution.Scheduler.global
    
    implicit val scheduler = {
      val em = global.executionModel
      global.withExecutionModel(em.withAutoCancelableLoops(true))
    }
    Definition Classes
    SchedulerServiceScheduler
  14. abstract def withUncaughtExceptionReporter(r: UncaughtExceptionReporter): SchedulerService

    Returns a new Scheduler that piggybacks on this, but uses the given exception reporter for reporting uncaught errors.

    Returns a new Scheduler that piggybacks on this, but uses the given exception reporter for reporting uncaught errors.

    Sample:

    import monix.execution.Scheduler.global
    import monix.execution.UncaughtExceptionReporter
    
    implicit val scheduler = {
      val r = UncaughtExceptionReporter { e =>
        e.printStackTrace()
      }
      global.withUncaughtExceptionReporter(r)
    }
    Definition Classes
    SchedulerServiceScheduler

Concrete Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##(): Int
    Definition Classes
    AnyRef → Any
  3. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  4. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  5. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
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    Annotations
    @throws(classOf[java.lang.CloneNotSupportedException]) @native()
  6. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  7. def equals(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef → Any
  8. def features: Features

    Exposes a set of flags that describes the Scheduler's features.

    Exposes a set of flags that describes the Scheduler's features.

    Definition Classes
    Scheduler
  9. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.Throwable])
  10. final def getClass(): Class[_ <: AnyRef]
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    AnyRef → Any
    Annotations
    @native()
  11. def hashCode(): Int
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    AnyRef → Any
    Annotations
    @native()
  12. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  13. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  14. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  15. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  16. final def synchronized[T0](arg0: => T0): T0
    Definition Classes
    AnyRef
  17. def toString(): String
    Definition Classes
    AnyRef → Any
  18. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  19. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  20. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
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    @throws(classOf[java.lang.InterruptedException]) @native()

Deprecated Value Members

  1. def prepare(): ExecutionContext
    Definition Classes
    ExecutionContext
    Annotations
    @deprecated
    Deprecated

    (Since version 2.12.0) preparation of ExecutionContexts will be removed

Inherited from Scheduler

Inherited from Executor

Inherited from Serializable

Inherited from ExecutionContext

Inherited from AnyRef

Inherited from Any

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