Class: Async::Task
- Extended by:
- Forwardable
- Defined in:
- lib/async/task.rb
Overview
A task represents the state associated with the execution of an asynchronous block.
Instance Attribute Summary collapse
- #fiber ⇒ Object readonly
- #reactor ⇒ Object readonly
- #status ⇒ Object readonly
Attributes inherited from Node
#annotation, #children, #parent
Class Method Summary collapse
-
.current ⇒ Async::Task
Lookup the Task for the current fiber.
-
.current? ⇒ Async::Task?
Check if there is a task defined for the current fiber.
-
.yield {|result| ... } ⇒ Object
Yield the unerlying
result
for the task.
Instance Method Summary collapse
- #alive? ⇒ Boolean
- #async(*args, **options, &block) ⇒ Object
- #complete? ⇒ Boolean
- #current? ⇒ Boolean
- #failed? ⇒ Boolean
-
#finished? ⇒ Boolean
Whether we can remove this node from the reactor graph.
-
#initialize(reactor, parent = Task.current?, logger: nil, &block) ⇒ Task
constructor
Create a new task.
- #logger ⇒ Object
-
#run(*args) ⇒ Object
Begin the execution of the task.
-
#running? ⇒ Boolean
Check if the task is running.
-
#stop(later = false) ⇒ void
Stop the task and all of its children.
- #stopped? ⇒ Boolean
- #stopping? ⇒ Boolean
- #to_s ⇒ Object
-
#wait ⇒ Object
(also: #result)
Retrieve the current result of the task.
-
#yield ⇒ Object
Yield back to the reactor and allow other fibers to execute.
Methods inherited from Node
#annotate, #consume, #description, #inspect, #print_hierarchy, #reap, #traverse
Constructor Details
#initialize(reactor, parent = Task.current?, logger: nil, &block) ⇒ Task
Create a new task.
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# File 'lib/async/task.rb', line 73 def initialize(reactor, parent = Task.current?, logger: nil, &block) super(parent || reactor) @reactor = reactor @status = :initialized @result = nil @finished = nil @logger = logger @fiber = make_fiber(&block) end |
Instance Attribute Details
#fiber ⇒ Object (readonly)
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# File 'lib/async/task.rb', line 105 def fiber @fiber end |
#reactor ⇒ Object (readonly)
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# File 'lib/async/task.rb', line 96 def reactor @reactor end |
#status ⇒ Object (readonly)
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# File 'lib/async/task.rb', line 112 def status @status end |
Class Method Details
.current ⇒ Async::Task
Lookup the Async::Task for the current fiber. Raise RuntimeError
if none is available.
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# File 'lib/async/task.rb', line 181 def self.current Thread.current[:async_task] or raise RuntimeError, "No async task available!" end |
.current? ⇒ Async::Task?
Check if there is a task defined for the current fiber.
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# File 'lib/async/task.rb', line 187 def self.current? Thread.current[:async_task] end |
.yield {|result| ... } ⇒ Object
Yield the unerlying result
for the task. If the result
is an Exception, then that result will be raised an its
exception.
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# File 'lib/async/task.rb', line 56 def self.yield if block_given? result = yield else result = Fiber.yield end if result.is_a? Exception raise result else return result end end |
Instance Method Details
#alive? ⇒ Boolean
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# File 'lib/async/task.rb', line 107 def alive? @fiber&.alive? end |
#async(*args, **options, &block) ⇒ Object
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# File 'lib/async/task.rb', line 124 def async(*args, **, &block) task = Task.new(@reactor, self, **, &block) task.run(*args) return task end |
#complete? ⇒ Boolean
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# File 'lib/async/task.rb', line 219 def complete? @status == :complete end |
#current? ⇒ Boolean
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# File 'lib/async/task.rb', line 191 def current? self.equal?(Thread.current[:async_task]) end |
#failed? ⇒ Boolean
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# File 'lib/async/task.rb', line 207 def failed? @status == :failed end |
#finished? ⇒ Boolean
Whether we can remove this node from the reactor graph.
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# File 'lib/async/task.rb', line 203 def finished? super && @status != :running end |
#logger ⇒ Object
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# File 'lib/async/task.rb', line 91 def logger @logger ||= @parent&.logger end |
#run(*args) ⇒ Object
Begin the execution of the task.
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# File 'lib/async/task.rb', line 115 def run(*args) if @status == :initialized @status = :running @fiber.resume(*args) else raise RuntimeError, "Task already running!" end end |
#running? ⇒ Boolean
Check if the task is running.
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# File 'lib/async/task.rb', line 197 def running? @status == :running end |
#stop(later = false) ⇒ void
This method returns an undefined value.
Stop the task and all of its children.
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# File 'lib/async/task.rb', line 152 def stop(later = false) if self.stopped? # If we already stopped this task... don't try to stop it again: return end if self.running? if self.current? if later @reactor << Stop::Later.new(self) else raise Stop, "Stopping current task!" end elsif @fiber&.alive? begin @fiber.resume(Stop.new) rescue FiberError @reactor << Stop::Later.new(self) end end else # We are not running, but children might be, so transition directly into stopped state: stop! end end |
#stopped? ⇒ Boolean
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# File 'lib/async/task.rb', line 215 def stopped? @status == :stopped end |
#stopping? ⇒ Boolean
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# File 'lib/async/task.rb', line 211 def stopping? @status == :stopping end |
#to_s ⇒ Object
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# File 'lib/async/task.rb', line 87 def to_s "\#<#{self.description} (#{@status})>" end |
#wait ⇒ Object Also known as: result
Retrieve the current result of the task. Will cause the caller to wait until result is available.
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# File 'lib/async/task.rb', line 135 def wait raise RuntimeError, "Cannot wait on own fiber" if Fiber.current.equal?(@fiber) if running? @finished ||= Condition.new @finished.wait else Task.yield{@result} end end |