Bug #21947: `Timeout.timeout` doesn't use `Timeout::ExitException` when Fiber scheduler is in use.

• Status: Closed
• Assignee: ioquatix (Samuel Williams)
• Target version: -
• Backport: 3.3: REQUIRED, 3.4: REQUIRED, 4.0: REQUIRED

[ioquatix (Samuel Williams)]

The following example executes successfully after 7 seconds instead of timing out after 2.

require 'async'
require 'net/http'

start = Time.now

Sync do
  Timeout.timeout 2 do
    Net::HTTP.get(URI 'https://httpbin.org/delay/5')

    puts "...request finished, no timeout though; in #{Time.now - start}s"
  end
end

puts "Duration: #{Time.now - start}s"

# => ...request finished, no timeout though; in 7.7007s
# Duration: 7.700962s

There are two issues:

• Net::HTTP rescues Timeout::Error and retries. This causes 2s (timeout -> retry) + 5s execution time.
• Timeout.timeout uses Timeout::ExitException when no exception is specified, but the Fiber scheduler code path was not updated.

See https://github.com/socketry/async/issues/448 for more discussion.

[ioquatix (Samuel Williams)]

See https://github.com/ruby/timeout/pull/97 for a proposed fix.

• Status changed from Open to Closed

Applied in changeset git|f315d250b44e75a1a69f4a05b293dcc701377689.

---

[ruby/timeout] Compatibility with Fiber scheduler.
(https://github.com/ruby/timeout/pull/97)

[Bug #21947]

https://github.com/ruby/timeout/commit/55d7c84b50