mirror of
https://github.com/ruby/ruby.git
synced 2026-08-08 15:08:11 +08:00
ac596948d4
[PATCH] Fix sleep spurious wakeup from sigchld (#15802) When sleeping with `sleep`, currently the main thread can get woken up from sigchld from any thread (subprocess exited). The timer thread wakes up the main thread when this happens, as it checks for signals. The main thread then executes the ruby sigchld handler if one is registered and is supposed to go back to sleep immediately. This is not ideal but it's the way it's worked for a while. In commit 8d8159e7d8 I added writes to `th->status` before and after `wait_running_turn` in `thread_sched_to_waiting_until_wakeup`, which is called from `sleep`. This is usually the right way to set the thread's status, but `sleep` is an exception because the writes to `th->status` are done in `sleep_forever`. There's a loop that checks `th->status` in `sleep_forever`. When the main thread got woken up from sigchld it saw the changed `th->status` and continued to run the main thread instead of going back to sleep. The following script shows the error. It was returning instead of sleeping forever. ```ruby t = Thread.new do sleep 0.3 `echo hello` # Spawns subprocess puts "Subprocess exited" end puts "Main thread sleeping..." result = sleep # Should block forever puts "sleep returned: #{result.inspect}" ``` Fixes [Bug #21812]
35 lines
774 B
Ruby
35 lines
774 B
Ruby
# frozen_string_literal: false
|
|
require 'test/unit'
|
|
require 'etc'
|
|
require 'timeout'
|
|
|
|
class TestSleep < Test::Unit::TestCase
|
|
def test_sleep_5sec
|
|
EnvUtil.without_gc do
|
|
start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
|
|
sleep 5
|
|
slept = Process.clock_gettime(Process::CLOCK_MONOTONIC) - start
|
|
bottom = 5.0
|
|
assert_operator(slept, :>=, bottom)
|
|
assert_operator(slept, :<=, 6.0, "[ruby-core:18015]: longer than expected")
|
|
end
|
|
end
|
|
|
|
def test_sleep_forever_not_woken_by_sigchld
|
|
begin
|
|
t = Thread.new do
|
|
sleep 0.5
|
|
`echo hello`
|
|
end
|
|
|
|
assert_raise Timeout::Error do
|
|
Timeout.timeout 2 do
|
|
sleep # Should block forever
|
|
end
|
|
end
|
|
ensure
|
|
t.join
|
|
end
|
|
end
|
|
end
|