Module: AWS::Flow::Core

Defined in:
lib/aws/flow/fiber.rb,
lib/aws/flow/tasks.rb,
lib/aws/flow/future.rb,
lib/aws/flow/flow_utils.rb,
lib/aws/flow/simple_dfa.rb,
lib/aws/flow/async_scope.rb,
lib/aws/flow/implementation.rb,
lib/aws/flow/async_backtrace.rb,
lib/aws/flow/begin_rescue_ensure.rb

Defined Under Namespace

Modules: SimpleDFA Classes: AlreadySetException, BeginRescueEnsure, BeginRescueEnsureWrapper, CancellationException, DaemonBeginRescueEnsure, DaemonTask, ExternalTask, FiberConditionVariable, FlowFiber, Future, IllegalStateException, NoContextException, Task

Instance Method Summary collapse

Instance Method Details

#daemon_task(&block) ⇒ Future

Returns The tasks result, which is a Future.

Parameters:

  • block —

    The block of code to be executed when the daemon task is run.

Returns:

Raises:



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# File 'lib/aws/flow/implementation.rb', line 51

def daemon_task(&block)
  fiber = ::Fiber.current
  raise NoContextException unless fiber.respond_to? :__context__
  context = fiber.__context__
  t = DaemonTask.new(nil, &block)
  task_context = TaskContext.new(:parent => context.get_closest_containing_scope, :task => t)
  context << t
  t.result
end

#error_handler(&block) ⇒ Object

  • Args :

    • block -> a block, which is passed in a BeginRescueEnsureWrapper, and which will define the BeginRescueEnsure#begin, BeginRescueEnsure#rescue, and BeginRescueEnsure#ensure methods

  • Returns :

    • The result of the begin statement, if there is no error, otherwise the value of the return statement

  • Raises :

    • NoContextException -> If the current fiber does not respond to #__context__

Raises:



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# File 'lib/aws/flow/implementation.rb', line 90

def error_handler(&block)
  fiber = ::Fiber.current
  raise NoContextException unless fiber.respond_to? :__context__
  context = fiber.__context__
  begin_rescue_ensure = BeginRescueEnsure.new(:parent => context.get_closest_containing_scope)
  bge = BeginRescueEnsureWrapper.new(block, begin_rescue_ensure)
  context << bge
  context << begin_rescue_ensure
  begin_rescue_ensure
end

#external_task(&block) ⇒ nil

Parameters:

  • block —

    The block of code to be executed when the external task is run.

Returns:

  • (nil)

Raises:



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# File 'lib/aws/flow/implementation.rb', line 70

def external_task(&block)
  fiber = ::Fiber.current
  raise NoContextException unless fiber.respond_to? :__context__
  context = fiber.__context__
  t = ExternalTask.new(:parent => context.get_closest_containing_scope, &block)
  task_context = TaskContext.new(:parent => context.get_closest_containing_scope, :task => t)
  context << t
  nil
end

#gate_by_version(version, method, &block) ⇒ Object 



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

def gate_by_version(version, method, &block)
  if RUBY_VERSION.send(method, version)
    block.call
  end
end

#make_backtrace(parent_backtrace) ⇒ Object 



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# File 'lib/aws/flow/flow_utils.rb', line 29

def make_backtrace(parent_backtrace)
  # 1 frame for the function that actually removes the stack traces
  # 1 frame for the function that calls into the function that removes
  # frames in AsyncBacktrace
  # 1 frame for the call into this function
  # 1 frame for the initialize call of the BRE or External Task
  # 1 frame for the new call into the BRE or ET
  # 1 frame for the AsyncScope initialize that the BRE/ET has to be in

  # "./lib/aws/rubyflow/asyncBacktrace.rb:75:in `caller'"
  # "./lib/aws/rubyflow/asyncBacktrace.rb:21:in `create'"
  # "./lib/aws/rubyflow/flow.rb:16:in `make_backtrace'"
  # "./lib/aws/rubyflow/flow.rb:103:in `initialize'"
  # "./lib/aws/rubyflow/asyncScope.rb:17:in `new'"
  # "./lib/aws/rubyflow/asyncScope.rb:17:in `initialize'"

  frames_to_skip = 7
  backtrace = AsyncBacktrace.create(parent_backtrace, frames_to_skip)
end

#task(future = nil, &block) ⇒ Future

Returns The tasks result, which is a Future.

Parameters:

  • block —

    The block of code to be executed when the task is run.

Returns:

Raises:



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# File 'lib/aws/flow/implementation.rb', line 31

def task(future = nil, &block)
  fiber = ::Fiber.current
  raise NoContextException unless fiber.respond_to? :__context__
  context = fiber.__context__
  t = Task.new(nil, &block)
  task_context = TaskContext.new(:parent => context.get_closest_containing_scope, :task => t)
  context << t
  t.result
end

#wait_for_all(*futures) ⇒ Array

Blocks until all of the arguments are set.

Parameters:

  • futures (Array<Future>) —

    A list of futures to wait for. The function will return only when all of them are set.

Returns:

  • (Array) —

    A list of the set futures, in the order of being set.



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# File 'lib/aws/flow/implementation.rb', line 146

def wait_for_all(*futures)
  wait_for_function(lambda {|result, future_list| result.size == future_list.size}, futures)
end

#wait_for_any(*futures) ⇒ Array

Blocks until any of the arguments are set.

Parameters:

  • futures (Array) —

    A list of futures to wait for. The function will return when at least one of these is set.

Returns:

  • (Array) —

    A list of the set futures, in the order of being set.



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# File 'lib/aws/flow/implementation.rb', line 134

def wait_for_any(*futures)
  wait_for_function(lambda {|result, future_list| result.length >= 1 }, futures)
end

#wait_for_function(function, *futures) ⇒ Object 



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# File 'lib/aws/flow/implementation.rb', line 110

def wait_for_function(function, *futures)
  conditional = FiberConditionVariable.new
  futures.flatten!
  return nil if futures.empty?
  result = futures.select(&:set?)
  return futures.find(&:set?)if function.call(result, futures)
  futures.each do |f|
    f.on_set do |set_one|
      result << set_one
      conditional.broadcast if function.call(result, futures)
    end
  end
  conditional.wait
  result
end