class Celluloid::Future - celluloid-0.16.0 Documentation

# class Celluloid::Future

Celluloid::Future objects allow methods and blocks to run in the background, their values requested later

### Attributes

address[R]

### Public Class Methods

new() click to toggle source

    # File lib/celluloid/future.rb, line 24
    def initialize
      @address = Celluloid.uuid
      @mutex = Mutex.new
      @ready = false
      @result = nil
      @forwards = nil
    end

new(*args, &block) click to toggle source
Calls superclass method Object.new

    # File lib/celluloid/future.rb, line 7
    def self.new(*args, &block)
      return super unless block

      future = new
      Celluloid::ThreadHandle.new(Celluloid.actor_system, :future) do
        begin
          call = SyncCall.new(future, :call, args)
          call.dispatch(block)
        rescue
          # Exceptions in blocks will get raised when the value is retrieved
        end
      end
      future
    end

### Public Instance Methods

<<(value)
Alias for: signal
call(timeout = nil)
Alias for: value
ready?() click to toggle source

Check if this future has a value yet

    # File lib/celluloid/future.rb, line 33
    def ready?
      @ready
    end

signal(value) click to toggle source

Signal this future with the given result value

    # File lib/celluloid/future.rb, line 76
    def signal(value)
      result = Result.new(value, self)

      @mutex.synchronize do
        raise "the future has already happened!" if @ready

        if @forwards
          @forwards.is_a?(Array) ? @forwards.each { |f| f << result } : @forwards << result
        end

        @result = result
        @ready = true
      end
    end

Also aliased as: <<
value(timeout = nil) click to toggle source

Obtain the value for this Future

    # File lib/celluloid/future.rb, line 38
    def value(timeout = nil)
      ready = result = nil

      begin
        @mutex.lock

        if @ready
          ready = true
          result = @result
        else
          case @forwards
          when Array
            @forwards << Celluloid.mailbox
          when NilClass
            @forwards = Celluloid.mailbox
          else
            @forwards = [@forwards, Celluloid.mailbox]
          end
        end
      ensure
        @mutex.unlock
      end

      unless ready
        result = Celluloid.receive(timeout) do |msg|
          msg.is_a?(Future::Result) && msg.future == self
        end
      end

      if result
        result.value
      else
        raise TimeoutError, "Timed out"
      end
    end

Also aliased as: call