Package org.apache.pekko.stream

Class SharedKillSwitch

java.lang.Object
org.apache.pekko.stream.SharedKillSwitch
All Implemented Interfaces:
KillSwitch
public final class SharedKillSwitch extends Object implements KillSwitch
A SharedKillSwitch is a provider for Graphs of FlowShape that can be completed or failed from the outside. A Graph returned by the switch can be materialized arbitrary amount of times: every newly materialized Graph belongs to the switch from which it was acquired. Multiple SharedKillSwitch instances are isolated from each other, shutting down or aborting on instance does not affect the Graphs provided by another instance.

After calling shutdown() all materialized, running instances of all Graphs provided by the SharedKillSwitch will complete their downstreams and cancel their upstreams (unless if finished or failed already in which case the command is ignored). Subsequent invocations of shutdown() and abort(java.lang.Throwable) will be ignored.

After calling abort(java.lang.Throwable) all materialized, running instances of all Graphs provided by the SharedKillSwitch will fail their downstreams with the provided exception and cancel their upstreams (unless it finished or failed already in which case the command is ignored). Subsequent invocations of shutdown() and abort(java.lang.Throwable) will be ignored.

The Graphs provided by the SharedKillSwitch do not modify the passed through elements in any way or affect backpressure in the stream. All provided Graphs provide the parent SharedKillSwitch as materialized value.

This class is thread-safe, the instance can be passed safely among threads and its methods may be invoked concurrently.

  • Method Details

    • abort

      public void abort(Throwable reason)
      After calling abort(java.lang.Throwable) all materialized, running instances of all Graphs provided by the SharedKillSwitch will fail their downstreams with the provided exception and cancel their upstreams (unless it finished or failed already in which case the command is ignored). Subsequent invocations of shutdown() and abort(java.lang.Throwable) will be ignored.

      These provided Graphs materialize to their owning switch. This might make certain integrations simpler than passing around the switch instance itself.

      Specified by:
      abort in interface KillSwitch
      Parameters:
      reason - The exception to be used for failing the linked Graphs

    • flow

      public <T> Graph<FlowShape<T,T>,SharedKillSwitch> flow()
      Returns a typed Flow of a requested type that will be linked to this SharedKillSwitch instance. By invoking shutdown() or abort(java.lang.Throwable) all running instances of all provided Graphs by this switch will be stopped normally or failed.

      Returns:
      A reusable Graph that is linked with the switch. The materialized value provided is this switch itself.

    • name

      public String name()

    • shutdown

      public void shutdown()
      After calling shutdown() all materialized, running instances of all Graphs provided by the SharedKillSwitch will complete their downstreams and cancel their upstreams (unless if finished or failed already in which case the command is ignored). Subsequent invocations of shutdown() and abort(java.lang.Throwable) will be ignored.
      Specified by:
      shutdown in interface KillSwitch

    • toString

      public String toString()
      Overrides:
      toString in class Object