Class: Async::WorkerPool::Promise

Inherits:
Object
  • Object
show all
Defined in:
lib/async/worker_pool.rb

Overview

Execute the given work in a background thread.

Instance Method Summary collapse

Constructor Details

#initialize(work) ⇒ Promise

Create a new promise.



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# File 'lib/async/worker_pool.rb', line 32

def initialize(work)
  @work = work
  @state = :pending
  @value = nil
  @guard = ::Mutex.new
  @condition = ::ConditionVariable.new
  @thread = nil
end

Instance Method Details

#call ⇒ Object

Execute the work and resolve the promise.



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# File 'lib/async/worker_pool.rb', line 42

def call
  work = nil
  
  @guard.synchronize do
    @thread = ::Thread.current
    
    return unless work = @work
  end
  
  resolve(work.call)
rescue Exception => error
  reject(error)
end

#cancel ⇒ Object

Cancel the work and raise an exception in the background thread.



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# File 'lib/async/worker_pool.rb', line 77

def cancel
  return unless @work
  
  @guard.synchronize do
    @work = nil
    @state = :cancelled
    @thread&.raise(Interrupt)
  end
end

#wait ⇒ Object

Wait for the work to be done.



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# File 'lib/async/worker_pool.rb', line 90

def wait
  @guard.synchronize do
    while @state == :pending
      @condition.wait(@guard)
    end
    
    if @state == :failed
      raise @value
    else
      return @value
    end
  end
end