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, #head, #parent, #tail
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(*arguments, **options, &block) ⇒ Object
- #backtrace(*arguments) ⇒ 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, **options, &block) ⇒ Task
constructor
Create a new task.
- #logger ⇒ Object
-
#run(*arguments) ⇒ 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, #children?, #consume, #description, #print_hierarchy, #transient?, #traverse
Constructor Details
#initialize(reactor, parent = Task.current?, logger: nil, **options, &block) ⇒ Task
Create a new task.
75 76 77 78 79 80 81 82 83 84 85 86 87 |
# File 'lib/async/task.rb', line 75 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)
114 115 116 |
# File 'lib/async/task.rb', line 114 def fiber @fiber end |
#reactor ⇒ Object (readonly)
104 105 106 |
# File 'lib/async/task.rb', line 104 def reactor @reactor end |
#status ⇒ Object (readonly)
121 122 123 |
# File 'lib/async/task.rb', line 121 def status @status end |
Class Method Details
.current ⇒ Async::Task
Lookup the Async::Task for the current fiber. Raise ‘RuntimeError` if none is available.
191 192 193 |
# File 'lib/async/task.rb', line 191 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.
197 198 199 |
# File 'lib/async/task.rb', line 197 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.
58 59 60 61 62 63 64 65 66 67 68 69 70 |
# File 'lib/async/task.rb', line 58 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
116 117 118 |
# File 'lib/async/task.rb', line 116 def alive? @fiber&.alive? end |
#async(*arguments, **options, &block) ⇒ Object
134 135 136 137 138 139 140 |
# File 'lib/async/task.rb', line 134 def async(*arguments, **, &block) task = Task.new(@reactor, self, **, &block) task.run(*arguments) return task end |
#backtrace(*arguments) ⇒ Object
90 91 92 |
# File 'lib/async/task.rb', line 90 def backtrace(*arguments) @fiber&.backtrace(*arguments) end |
#complete? ⇒ Boolean
229 230 231 |
# File 'lib/async/task.rb', line 229 def complete? @status == :complete end |
#current? ⇒ Boolean
201 202 203 |
# File 'lib/async/task.rb', line 201 def current? self.equal?(Thread.current[:async_task]) end |
#failed? ⇒ Boolean
217 218 219 |
# File 'lib/async/task.rb', line 217 def failed? @status == :failed end |
#finished? ⇒ Boolean
Whether we can remove this node from the reactor graph.
213 214 215 |
# File 'lib/async/task.rb', line 213 def finished? super && @status != :running end |
#logger ⇒ Object
99 100 101 |
# File 'lib/async/task.rb', line 99 def logger @logger || Console.logger end |
#run(*arguments) ⇒ Object
Begin the execution of the task.
124 125 126 127 128 129 130 131 132 |
# File 'lib/async/task.rb', line 124 def run(*arguments) if @status == :initialized @status = :running @fiber.resume(*arguments) else raise RuntimeError, "Task already running!" end end |
#running? ⇒ Boolean
Check if the task is running.
207 208 209 |
# File 'lib/async/task.rb', line 207 def running? @status == :running end |
#stop(later = false) ⇒ void
This method returns an undefined value.
Stop the task and all of its children.
162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 |
# File 'lib/async/task.rb', line 162 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
225 226 227 |
# File 'lib/async/task.rb', line 225 def stopped? @status == :stopped end |
#stopping? ⇒ Boolean
221 222 223 |
# File 'lib/async/task.rb', line 221 def stopping? @status == :stopping end |
#to_s ⇒ Object
95 96 97 |
# File 'lib/async/task.rb', line 95 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.
145 146 147 148 149 150 151 152 153 154 |
# File 'lib/async/task.rb', line 145 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 |