Class: Procrastinate::Task::Result

Inherits:
Object
  • Object
show all
Defined in:
lib/procrastinate/task/result.rb

Overview

A single value result, like from a normal method call. Return an instance of this from your task#result method to enable result handling.

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Result

Returns a new instance of Result.



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# File 'lib/procrastinate/task/result.rb', line 8

def initialize
  @value_ready    = Procrastinate::Utils::OneTimeFlag.new
  @value          = nil
  @exception      = false
end

Instance Method Details

#incoming_message(obj) ⇒ Object

Gets passed all messages sent by the child process for this task.

*control thread*



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# File 'lib/procrastinate/task/result.rb', line 17

def incoming_message(obj)
  return if ready?
  
  @value = obj
  @value_ready.set
end

#process_died ⇒ Object

Notifies this result that the process has died. If this happens before a process result is passed to #incoming_message, that message will never arrive. 

*control thread*



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# File 'lib/procrastinate/task/result.rb', line 29

def process_died
  return if ready?
  
  @exception = true    
  @value_ready.set
end

#ready? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/procrastinate/task/result.rb', line 46

def ready?
  @value_ready.set?
end

#value ⇒ Object 



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# File 'lib/procrastinate/task/result.rb', line 36

def value
  @value_ready.wait
  
  if @exception
    raise Procrastinate::ChildDeath, "Child process died before producing a value."
  else
    @value
  end
end