9bc01ae265
The idea is to filter the sources, replacing @<var>@ occurrences with the mapping for <var> (which is currently hard-coded). @@ -> @. In order to make this work, I had to move the doc sources one directory down (into akka-docs/rst) so that the filtered result could be in a sibling directory so that relative links (to _sphinx plugins or real code) would continue to work. While I was at it I also changed it so that WARNINGs and ERRORs are not swallowed into the debug dump anymore but printed at [warn] level (minimum). One piece of fallout is that the (online) html build is now run after the normal one, not in parallel.
60 lines
2.2 KiB
ReStructuredText
60 lines
2.2 KiB
ReStructuredText
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.. _scheduler-scala:
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###################
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Scheduler (Scala)
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###################
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Sometimes the need for making things happen in the future arises, and where do you go look then?
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Look no further than ``ActorSystem``! There you find the :meth:`scheduler` method that returns an instance
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of akka.actor.Scheduler, this instance is unique per ActorSystem and is used internally for scheduling things
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to happen at specific points in time. Please note that the scheduled tasks are executed by the default
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``MessageDispatcher`` of the ``ActorSystem``.
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You can schedule sending of messages to actors and execution of tasks (functions or Runnable).
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You will get a ``Cancellable`` back that you can call :meth:`cancel` on to cancel the execution of the
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scheduled operation.
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.. warning::
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The default implementation of ``Scheduler`` used by Akka is based on the Netty ``HashedWheelTimer``.
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It does not execute tasks at the exact time, but on every tick, it will run everything that is overdue.
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The accuracy of the default Scheduler can be modified by the "ticks-per-wheel" and "tick-duration" configuration
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properties. For more information, see: `HashedWheelTimers <http://www.cse.wustl.edu/~cdgill/courses/cs6874/TimingWheels.ppt>`_.
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Some examples
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-------------
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.. includecode:: code/docs/actor/SchedulerDocSpec.scala
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:include: imports1,schedule-one-off-message
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.. includecode:: code/docs/actor/SchedulerDocSpec.scala
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:include: schedule-one-off-thunk
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.. includecode:: code/docs/actor/SchedulerDocSpec.scala
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:include: schedule-recurring
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From ``akka.actor.ActorSystem``
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-------------------------------
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.. includecode:: ../../../akka-actor/src/main/scala/akka/actor/ActorSystem.scala
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:include: scheduler
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The Scheduler interface
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-----------------------
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.. includecode:: ../../../akka-actor/src/main/scala/akka/actor/Scheduler.scala
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:include: scheduler
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The Cancellable interface
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-------------------------
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This allows you to ``cancel`` something that has been scheduled for execution.
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.. warning::
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This does not abort the execution of the task, if it had already been started.
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.. includecode:: ../../../akka-actor/src/main/scala/akka/actor/Scheduler.scala
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:include: cancellable
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