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Class: Kward::PluginTask

Inherits:
Object
  • Object
show all
Defined in:
lib/kward/plugins/resources.rb

Overview

Cooperative background task owned by a plugin runtime.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name:, cancellation:, &work) ⇒ PluginTask

Returns a new instance of PluginTask.



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# File 'lib/kward/plugins/resources.rb', line 42

def initialize(name:, cancellation:, &work)
  @name = name.to_s.freeze
  @cancellation = cancellation
  @work = work
  @mutex = Mutex.new
  @thread = nil
  @result = nil
  @error = nil
end

Instance Attribute Details

#cancellation ⇒ Object (readonly)

Returns the value of attribute cancellation.



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# File 'lib/kward/plugins/resources.rb', line 40

def cancellation
  @cancellation
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/kward/plugins/resources.rb', line 40

def name
  @name
end

Instance Method Details

#alive? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/kward/plugins/resources.rb', line 83

def alive?
  thread = @mutex.synchronize { @thread }
  thread&.alive? == true
end

#cancel! ⇒ Object 



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# File 'lib/kward/plugins/resources.rb', line 74

def cancel!
  cancellation.cancel!
  self
end

#cancelled? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/kward/plugins/resources.rb', line 79

def cancelled?
  cancellation.cancelled?
end

#complete? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/kward/plugins/resources.rb', line 88

def complete?
  !alive?
end

#error ⇒ Object 



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# File 'lib/kward/plugins/resources.rb', line 103

def error
  @mutex.synchronize { @error }
end

#join(timeout = nil) ⇒ Object 



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# File 'lib/kward/plugins/resources.rb', line 92

def join(timeout = nil)
  thread = @mutex.synchronize { @thread }
  thread&.join(timeout)
  self
end

#result ⇒ Object 



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# File 'lib/kward/plugins/resources.rb', line 98

def result
  join
  @mutex.synchronize { @result }
end

#start(&finished) ⇒ Object 



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# File 'lib/kward/plugins/resources.rb', line 52

def start(&finished)
  @mutex.synchronize do
    raise "Plugin task #{name.inspect} has already started" if @thread

    @thread = Thread.new do
      begin
        cancellation.raise_if_cancelled!
        result = @work.arity.zero? ? @work.call : @work.call(cancellation)
        @mutex.synchronize { @result = result }
      rescue Cancellation::CancelledError
        nil
      rescue StandardError => e
        @mutex.synchronize { @error = e }
      ensure
        finished&.call(self)
      end
    end
    @thread.report_on_exception = false
  end
  self
end