Class: Concurrent::Agent

Inherits:
Object
  • Object
show all
Includes:
Dereferenceable, UsesGlobalThreadPool, Observable
Defined in:
lib/concurrent/agent.rb

Overview

An agent is a single atomic value that represents an identity. The current value of the agent can be requested at any time (#deref). Each agent has a work queue and operates on the global thread pool. Consumers can #post code blocks to the agent. The code block (function) will receive the current value of the agent as its sole parameter. The return value of the block will become the new value of the agent. Agents support two error handling modes: fail and continue. A good example of an agent is a shared incrementing counter, such as the score in a video game.

Defined Under Namespace

Classes: Rescuer

Constant Summary collapse

TIMEOUT = 
5

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from UsesGlobalThreadPool

included

Methods included from Dereferenceable

#set_deref_options, #value

Constructor Details

#initialize(initial, opts = {}) ⇒ Agent

Returns a new instance of Agent.



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# File 'lib/concurrent/agent.rb', line 26

def initialize(initial, opts = {})
  @value = initial
  @rescuers = []
  @validator = nil
  @timeout = opts[:timeout] || TIMEOUT
  set_deref_options(opts)
end

Instance Attribute Details

#initial ⇒ Object (readonly)

Returns the value of attribute initial.



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# File 'lib/concurrent/agent.rb', line 23

def initial
  @initial
end

#timeout ⇒ Object (readonly)

Returns the value of attribute timeout.



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# File 'lib/concurrent/agent.rb', line 24

def timeout
  @timeout
end

Instance Method Details

#<<(block) ⇒ Object 



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# File 'lib/concurrent/agent.rb', line 57

def <<(block)
  self.post(&block)
  return self
end

#post(&block) ⇒ Object 



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# File 'lib/concurrent/agent.rb', line 53

def post(&block)
  Agent.thread_pool.post{ work(&block) } unless block.nil?
end

#rescue(clazz = nil, &block) ⇒ Object Also known as: catch, on_error 



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# File 'lib/concurrent/agent.rb', line 34

def rescue(clazz = nil, &block)
  unless block.nil?
    mutex.synchronize do
      @rescuers << Rescuer.new(clazz, block)
    end
  end
  return self
end

#validate(&block) ⇒ Object Also known as: validates, validate_with, validates_with 



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# File 'lib/concurrent/agent.rb', line 45

def validate(&block)
  @validator = block unless block.nil?
  return self
end