Class: Concurrent::Actor::Utils::Pool

Inherits:
RestartingContext show all
Defined in:
lib/concurrent/actor/utils/pool.rb

Overview

Allows to create a pool of workers and distribute work between them

Examples:

class Worker < Concurrent::Actor::RestartingContext
  def on_message(message)
    p message * 5
  end
end

pool = Concurrent::Actor::Utils::Pool.spawn! 'pool', 5 do |index|
  Worker.spawn name: "worker-#{index}", supervise: true, args: []
end

pool << 'asd' << 2
# prints:
# "asdasdasdasdasd"
# 10

Yields:

  • (balancer, index) —

    a block spawning an worker instance. called size times. The worker should be descendant of AbstractWorker and supervised, see example.

Yield Parameters:

  • balancer (Balancer) —

    to pass to the worker

  • index (Integer) —

    of the worker, usually used in its name

Yield Returns:

  • (Reference) —

    the reference of newly created worker

Instance Attribute Summary

Attributes inherited from AbstractContext

#core

Instance Method Summary collapse

Methods inherited from RestartingContext

#behaviour_definition

Methods inherited from AbstractContext

#ask, #behaviour_definition, #dead_letter_routing, #default_executor, #default_reference_class, #envelope, #on_envelope, #on_event, #pass, spawn, spawn!, #tell

Methods included from InternalDelegations

#behaviour, #behaviour!, #children, #context, #dead_letter_routing, #log, #redirect, #terminate!, #terminated?

Methods included from PublicDelegations

#context_class, #executor, #name, #parent, #path, #reference

Methods included from TypeCheck

#Child!, #Child?, #Match!, #Match?, #Type!, #Type?

Constructor Details

#initialize(size, &worker_initializer) ⇒ Pool

Returns a new instance of Pool.



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# File 'lib/concurrent/actor/utils/pool.rb', line 30

def initialize(size, &worker_initializer)
  @balancer = Balancer.spawn name: :balancer, supervise: true
  @workers  = ::Array.new(size, &worker_initializer)
  @workers.each do |worker|
    Type! worker, Reference
    @balancer << [:subscribe, worker]
  end
end

Instance Method Details

#on_message(message) ⇒ Object 



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# File 'lib/concurrent/actor/utils/pool.rb', line 39

def on_message(message)
  command, _ = message
  return if [:restarted, :reset, :resumed, :terminated].include? command # ignore events from supervised actors

  envelope_to_redirect = if envelope.future
                           envelope
                         else
                           Envelope.new(envelope.message, Concurrent.future, envelope.sender, envelope.address)
                         end
  envelope_to_redirect.future.on_completion! { @balancer << :subscribe } # TODO check safety of @balancer reading
  redirect @balancer, envelope_to_redirect
end