Class: AWS::Flow::Core::Task

Inherits:
FlowFiber
  • Object
show all
Defined in:
lib/aws/flow/tasks.rb

Direct Known Subclasses

DaemonTask

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from FlowFiber

#[], [], []=, #[]=, finalize, unset

Constructor Details

#initialize(__context__, &block) ⇒ Task

Creates a new Task.

Parameters:

  • __context__ —

    A Task needs a reference to the __context__ that created it so that when the “task” macro is called it can find the __context__ which the new Task should be added to.

  • block —

    A block of code that will be run by the task.



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# File 'lib/aws/flow/tasks.rb', line 34

def initialize(__context__, &block)
  @__context__ = __context__
  @result = Future.new
  @block = block

  # Is the task alive?
  def alive?
    super && !@cancelled
    #!!@alive# && !@cancelled
  end

  # @return
  #   The executor for this task.
  def executor
    @__context__.executor
  end

  super() do
    begin
      # Not return because 1.9 will freak about local jump problems if you
      # try to return, as this is inside a block
      next if @cancelled
      @result.set(lambda(&block).call)
      next if @cancelled
      @__context__.remove(self)
    rescue Exception => e
      if @backtrace != e
        backtrace = AsyncBacktrace.create_from_exception(@backtrace, e)
        e.set_backtrace(backtrace.backtrace) if backtrace
      end
      @__context__.fail(self, e)
    ensure
    end
  end
end

Instance Attribute Details

#__context__ ⇒ Object

Returns the value of attribute __context__.



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# File 'lib/aws/flow/tasks.rb', line 23

def __context__
  @__context__
end

#backtrace ⇒ Object

Returns the value of attribute backtrace.



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# File 'lib/aws/flow/tasks.rb', line 23

def backtrace
  @backtrace
end

#block ⇒ Object (readonly)

Returns the value of attribute block.



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# File 'lib/aws/flow/tasks.rb', line 22

def block
  @block
end

#parent ⇒ Object

Returns the value of attribute parent.



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# File 'lib/aws/flow/tasks.rb', line 23

def parent
  @parent
end

#result ⇒ Object (readonly)

Returns the value of attribute result.



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# File 'lib/aws/flow/tasks.rb', line 22

def result
  @result
end

Instance Method Details

#<<(this_task) ⇒ Object

Adds a task to this task’s context

Parameters:

  • this_task —

    The task to add.



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# File 'lib/aws/flow/tasks.rb', line 120

def <<(this_task)
  @__context__.parent << this_task
end

#alive? ⇒ Boolean

Is the task alive?

Returns:

  • (Boolean) 


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# File 'lib/aws/flow/tasks.rb', line 40

def alive?
  super && !@cancelled
  #!!@alive# && !@cancelled
end

#cancel(error) ⇒ Object

Cancel will prevent the execution of this particular task, if possible

Parameters:

  • error —

    The error that is the cause of the cancellation



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# File 'lib/aws/flow/tasks.rb', line 97

def cancel(error)
  @cancelled = true
  @__context__.remove(self)
end

#executor ⇒ Object

Returns The executor for this task.

Returns:

  • The executor for this task.



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# File 'lib/aws/flow/tasks.rb', line 47

def executor
  @__context__.executor
end

#get_heirs ⇒ Object

Passes the get_heirs calls to the context, to ensure uniform handling of get_heirs



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# File 'lib/aws/flow/tasks.rb', line 73

def get_heirs
  @__context__.get_heirs
end

#is_daemon? ⇒ Boolean

Returns true/false, depending on if we are in a daemon task or not

Returns:

  • (Boolean) 


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# File 'lib/aws/flow/tasks.rb', line 80

def is_daemon?
  return false
end

#remove(this_task) ⇒ Object

Removes a task from this task’s context

Parameters:

  • this_task —

    The task to remove.



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# File 'lib/aws/flow/tasks.rb', line 129

def remove(this_task)
  @__context__.remove(this_task)
end

#schedule ⇒ Object

Used by Future#signal to schedule the task for re-evaluation.

This will simply add the task back to the list of things to be run in the parent’s event loop.



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# File 'lib/aws/flow/tasks.rb', line 88

def schedule
  @__context__ << self
end