Class: FiberScheduler

Inherits:
Object
  • Object
show all
Defined in:
lib/fiber_scheduler/selector.rb,
lib/fiber_scheduler.rb,
lib/fiber_scheduler/timeout.rb,
lib/fiber_scheduler/version.rb,
lib/fiber_scheduler/timeouts.rb,
lib/fiber_scheduler/compatibility.rb

Overview

The code in this class has been taken from io-event gem. It has been cleaned up and appropriated for use in this gem.

Defined Under Namespace

Modules: Compatibility Classes: Selector, Timeout, Timeouts

Constant Summary collapse

Error = 
Class.new(RuntimeError)
VERSION = 
"0.13.0".freeze

Instance Method Summary collapse

Constructor Details

#initialize ⇒ FiberScheduler

Returns a new instance of FiberScheduler.



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# File 'lib/fiber_scheduler.rb', line 100

def initialize
  @fiber = Fiber.current
  @selector =
    if defined?(IO::Event)
      IO::Event::Selector.new(@fiber)
    else
      Selector.new(@fiber)
    end
  @timeouts = Timeouts.new

  @count = 0
  @nested = []
end

Instance Method Details

#address_resolve(hostname) ⇒ Object 



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# File 'lib/fiber_scheduler.rb', line 163

def address_resolve(hostname)
  Resolv.getaddresses(hostname)
end

#block(blocker, duration = nil) ⇒ Object 



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# File 'lib/fiber_scheduler.rb', line 145

def block(blocker, duration = nil)
  return @selector.transfer unless duration

  @timeouts.timeout(duration, method: :transfer) do
    @selector.transfer
  end
end

#close ⇒ Object

Fiber::SchedulerInterface methods below



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# File 'lib/fiber_scheduler.rb', line 134

def close
  return unless @selector

  begin
    run
  ensure
    @selector.close
    @selector = nil
  end
end

#fiber(type = nil, &block) ⇒ Object 



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# File 'lib/fiber_scheduler.rb', line 191

def fiber(type = nil, &block)
  current = Fiber.current

  case type
  when :blocking
    Fiber.new(blocking: true, &block).tap(&:resume)

  when :waiting
    finished = false # prevents races
    fiber = Fiber.new(blocking: false) do
      @count += 1
      block.call
    ensure
      @count -= 1
      finished = true
      # Resume waiting parent fiber
      current.transfer
    end
    fiber.transfer

    # Current fiber is waiting until waiting fiber finishes.
    if current == @fiber
      # In a top-level fiber, there's nothing we can transfer to, so run
      # other fibers (or just block) until waiting fiber finishes.
      until finished
        run_once
      end
    elsif !finished
      @selector.transfer
    end

    fiber

  when :volatile
    if current != @fiber
      # nested Fiber.schedule
      @nested << current
    end

    Fiber.new(blocking: false, &block).tap(&:transfer)

  when nil
    if current != @fiber
      # nested Fiber.schedule
      @nested << current
    end

    fiber = Fiber.new(blocking: false) do
      @count += 1
      block.call
    ensure
      @count -= 1
    end
    fiber.tap(&:transfer)

  else
    raise "Unknown type"
  end
end

#io_read(io, buffer, length) ⇒ Object 



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# File 'lib/fiber_scheduler.rb', line 175

def io_read(io, buffer, length)
  @selector.io_read(Fiber.current, io, buffer, length)
end

#io_wait(io, events, duration = nil) ⇒ Object 



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# File 'lib/fiber_scheduler.rb', line 167

def io_wait(io, events, duration = nil)
  return @selector.io_wait(Fiber.current, io, events) unless duration

  @timeouts.timeout(duration, method: :transfer) do
    @selector.io_wait(Fiber.current, io, events)
  end
end

#io_write(io, buffer, length) ⇒ Object 



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# File 'lib/fiber_scheduler.rb', line 179

def io_write(io, buffer, length)
  @selector.io_write(Fiber.current, io, buffer, length)
end

#kernel_sleep(duration = nil) ⇒ Object 



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# File 'lib/fiber_scheduler.rb', line 157

def kernel_sleep(duration = nil)
  return @selector.transfer unless duration

  block(:sleep, duration)
end

#process_wait(pid, flags) ⇒ Object 



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# File 'lib/fiber_scheduler.rb', line 183

def process_wait(pid, flags)
  @selector.process_wait(Fiber.current, pid, flags)
end

#run ⇒ Object 



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# File 'lib/fiber_scheduler.rb', line 114

def run
  while @count > 0
    run_once
  end
end

#run_once ⇒ Object 



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# File 'lib/fiber_scheduler.rb', line 120

def run_once
  if @nested.empty?
    @selector.select(@timeouts.interval)
    @timeouts.call
  else
    while @nested.any?
      fiber = @nested.pop
      fiber.transfer
    end
  end
end

#timeout_after(duration, exception = Timeout::Error, message = "timeout", &block) ⇒ Object 



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# File 'lib/fiber_scheduler.rb', line 187

def timeout_after(duration, exception = Timeout::Error, message = "timeout", &block)
  @timeouts.timeout(duration, exception, message, &block)
end

#unblock(blocker, fiber) ⇒ Object 



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# File 'lib/fiber_scheduler.rb', line 153

def unblock(blocker, fiber)
  @selector.push(fiber)
end