diff options
author | Samuel Williams <samuel.williams@oriontransfer.co.nz> | 2021-07-28 19:55:55 +1200 |
---|---|---|
committer | Samuel Williams <samuel.williams@oriontransfer.co.nz> | 2021-08-03 22:23:48 +1200 |
commit | 2d4f29e77e883c29e35417799f8001b8046cde03 (patch) | |
tree | c2201611275519a9f36b7d3d3ce79583bc7ba14f /test | |
parent | 785c70e764c3222f9accac2555246d3921a7263d (diff) | |
download | ruby-2d4f29e77e883c29e35417799f8001b8046cde03.tar.gz |
Fix potential hang when joining threads.
If the thread termination invokes user code after `th->status` becomes
`THREAD_KILLED`, and the user unblock function causes that `th->status` to
become something else (e.g. `THREAD_RUNNING`), threads waiting in
`thread_join_sleep` will hang forever. We move the unblock function call
to before the thread status is updated, and allow threads to join as soon
as `th->value` becomes defined.
This reverts commit 6505c77501f1924571b2fe620c5c7b31ede0cd22.
Diffstat (limited to 'test')
-rw-r--r-- | test/fiber/scheduler.rb | 16 | ||||
-rw-r--r-- | test/fiber/test_thread.rb | 39 |
2 files changed, 53 insertions, 2 deletions
diff --git a/test/fiber/scheduler.rb b/test/fiber/scheduler.rb index af64e4ebb6..2785561000 100644 --- a/test/fiber/scheduler.rb +++ b/test/fiber/scheduler.rb @@ -112,8 +112,10 @@ class Scheduler self.run ensure - @urgent.each(&:close) - @urgent = nil + if @urgent + @urgent.each(&:close) + @urgent = nil + end @closed = true @@ -240,3 +242,13 @@ class BrokenUnblockScheduler < Scheduler raise "Broken unblock!" end end + +class SleepingUnblockScheduler < Scheduler + # This method is invoked when the thread is exiting. + def unblock(blocker, fiber) + super + + # This changes the current thread state to `THREAD_RUNNING` which causes `thread_join_sleep` to hang. + sleep(0.1) + end +end diff --git a/test/fiber/test_thread.rb b/test/fiber/test_thread.rb index 843604b5f1..5c25c43de2 100644 --- a/test/fiber/test_thread.rb +++ b/test/fiber/test_thread.rb @@ -20,6 +20,31 @@ class TestFiberThread < Test::Unit::TestCase assert_equal :done, thread.value end + def test_thread_join_implicit + sleeping = false + finished = false + + thread = Thread.new do + scheduler = Scheduler.new + Fiber.set_scheduler scheduler + + Fiber.schedule do + sleeping = true + sleep(0.1) + finished = true + end + + :done + end + + Thread.pass until sleeping + + thread.join + + assert_equal :done, thread.value + assert finished, "Scheduler thread's task should be finished!" + end + def test_thread_join_blocking thread = Thread.new do scheduler = Scheduler.new @@ -66,4 +91,18 @@ class TestFiberThread < Test::Unit::TestCase thread.join end end + + def test_thread_join_hang + thread = Thread.new do + scheduler = SleepingUnblockScheduler.new + + Fiber.set_scheduler scheduler + + Fiber.schedule do + Thread.new{sleep(0.01)}.value + end + end + + thread.join + end end |