Class: Async::Background::Runtime::Task

Inherits:
Object
  • Object
show all
Defined in:
lib/async/background/runtime/task.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name: nil, group: nil, on_error: UNSET) ⇒ Task

Returns a new instance of Task.



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# File 'lib/async/background/runtime/task.rb', line 15

def initialize(name: nil, group: nil, on_error: UNSET)
  @fiber = @scheduler = @blocker = @result = @error = nil
  @done = @cancelled = false

  @name = name
  @group = group
  @on_error = on_error
  @waiters = nil
end

Instance Attribute Details

#error ⇒ Object (readonly)

Returns the value of attribute error.



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# File 'lib/async/background/runtime/task.rb', line 7

def error
  @error
end

#fiber ⇒ Object (readonly)

Returns the value of attribute fiber.



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# File 'lib/async/background/runtime/task.rb', line 7

def fiber
  @fiber
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/async/background/runtime/task.rb', line 7

def name
  @name
end

Class Method Details

.spawn(name: nil, on_error: UNSET, &block) ⇒ Object 



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# File 'lib/async/background/runtime/task.rb', line 9

def self.spawn(name: nil, on_error: UNSET, &block)
  task = new(name: name, on_error: on_error)
  task.start(&block)
  task
end

Instance Method Details

#cancelled? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/async/background/runtime/task.rb', line 77

def cancelled? = @cancelled

#enter_block(waiter) ⇒ Object 



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# File 'lib/async/background/runtime/task.rb', line 85

def enter_block(waiter)
  @blocker = waiter
end

#exit_block ⇒ Object 



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# File 'lib/async/background/runtime/task.rb', line 89

def exit_block
  @blocker = nil
end

#finished? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/async/background/runtime/task.rb', line 78

def finished? = @done

#raise_if_cancelled! ⇒ Object

Raises:



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# File 'lib/async/background/runtime/task.rb', line 81

def raise_if_cancelled!
  raise Cancel, 'task stopped' if @cancelled
end

#start(&block) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/async/background/runtime/task.rb', line 25

def start(&block)
  raise ArgumentError, 'block required' unless block
  raise Error, 'task already started' if @fiber || @done

  @scheduler = Runtime.scheduler!
  takes_task = !block.arity.zero?

  scheduled = Fiber.schedule do
    adopt_fiber(Fiber.current)
    previous = Runtime.current_task
    Runtime.current_task = self
    begin
      complete(takes_task ? block.call(self) : block.call, nil)
    rescue Cancel
      complete(nil, nil)
    rescue Exception => e # rubocop:disable Lint/RescueException
      complete(nil, e)
    ensure
      Runtime.current_task = previous
    end
  end

  @fiber ||= scheduled if scheduled.is_a?(Fiber)
  self
end

#stop ⇒ Object 



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# File 'lib/async/background/runtime/task.rb', line 66

def stop
  return false if @done

  @cancelled = true

  return true if interrupt_fiber
  return true if release_blocker

  false
end

#wait(timeout = nil) ⇒ Object

Raises:



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# File 'lib/async/background/runtime/task.rb', line 51

def wait(timeout = nil)
  unless @done
    deadline = Runtime.deadline_for(timeout)
    raise TimeoutError, 'task did not finish in time' unless join(deadline)
  end

  raise @error if @error

  @result
end

#waiting ⇒ Object 



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# File 'lib/async/background/runtime/task.rb', line 79

def waiting = @waiters ? @waiters.size : 0

#with_timeout(duration, &block) ⇒ Object 



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# File 'lib/async/background/runtime/task.rb', line 62

def with_timeout(duration, &block)
  Runtime.with_timeout(duration, &block)
end