Bug #6117: Transfers allowed into Fibers that have resumed into other fibers - Ruby trunk - Ruby Issue Tracking System

Bug #6117

Transfers allowed into Fibers that have resumed into other fibers

Added by loganb (Logan Bowers) about 6 years ago. Updated about 1 year ago.

Status:

Feedback

Priority:

Normal

Assignee:

ko1 (Koichi Sasada)

Target version:

ruby -v:

ruby 2.0.0dev (2012-03-06) [x86_64-darwin11.3.0]

Backport:

[ruby-core:43088]

Description

Consider the following code:

  require 'fiber'

  def foo
    order = []
    main_fiber = Fiber.current
    a = Fiber.new do 
      order << 2
      x = Fiber.new do
        order << 4
        main_fiber.transfer
        order << 6
      end
      order << 3
      x.resume
      order << 7
    end

    order << 1
    a.transfer
    order << 5
    a.transfer
    order << 8
  end

It produces output:

  [1, 2, 3, 4, 5, 7, 8]

Note: the missing 6. I'd expect either the array to be 1-8 OR for an exception to be raised after 5 when the main fiber attempts to transfer into a again.

Either it shouldn't be possible to transfer into a Fiber that is blocked resuming another Fiber, OR it should automatically resume the sub-Fiber.