Bug #17636: Race condition in check_rvalue_consistency_force when using ractors

• Status: Closed
• Assignee: ko1 (Koichi Sasada)
• Target version: -
• Backport: 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: DONE

[peterzhu2118 (Peter Zhu)]

GitHub PR

When RGENGC_CHECK_MODE is enabled and we use multiple ractors, there is a race condition in check_rvalue_consistency_force that causes an assertion to fail. It happens when a page is created during the call to is_pointer_to_heap, which causes the binary search to fail.

Reproduction

NUM_RACTORS = 10

rs = NUM_RACTORS.times.map do |i|
  Ractor.new(i) do |i|
    arr = []
    
    10_000.times do |j|
      arr << "foo.#{i}.#{j}"
    end

    arr
  end
end

arrs = rs.map { |r| r.take }

The crash log is attached below in crash.log.

[peterzhu2118 (Peter Zhu)]

• Description updated (diff)

[ko1 (Koichi Sasada)]

• Status changed from Open to Assigned
• Assignee set to ko1 (Koichi Sasada)

Thank you. I got same issue.

[ko1 (Koichi Sasada)]

• Status changed from Assigned to Closed

Applied in changeset git|07ab172ebef28bb82c2650694548d123802d6c22.

---

sync check_rvalue_consistency_force()

check_rvalue_consistency_force() uses is_pointer_to_heap() and
it should be synchronized with other ractors.
[Bug #17636]

[ko1 (Koichi Sasada)]

• Backport changed from 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: UNKNOWN to 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: REQUIRED

[naruse (Yui NARUSE)]

• Backport changed from 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: REQUIRED to 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: DONE

ruby_3_0 d3863cb2e80f27d26b521b2c957b21feacb900de merged revision(s) 07ab172ebef28bb82c2650694548d123802d6c22.