diff options
| author | Eric Wong <e@80x24.org> | 2021-10-09 02:24:45 +0000 |
|---|---|---|
| committer | Eric Wong <e@yhbt.net> | 2021-10-09 03:35:45 +0000 |
| commit | 8d44aa7c394d8b41af891a84e9b4fcca9358da41 (patch) | |
| tree | 8912d302ced74146b66040d0c51064c05eb8bfe5 | |
| parent | 88025df70e228fe9a9cf8676772eaa13aba68eb6 (diff) | |
| download | yahns-8d44aa7c394d8b41af891a84e9b4fcca9358da41.tar.gz | |
epoll_wait() wakeups from QueueQuitter got lost during graceful shutdown since there's multiple worker threads operating off the same FD. Workaround the problem by re-arming the eventfd for every worker thread reaped. Link: https://yhbt.net/lore/lkml/20210405231025.33829-1-dave@stgolabs.net/
| -rw-r--r-- | lib/yahns/queue_epoll.rb | 4 | ||||
| -rw-r--r-- | lib/yahns/server.rb | 17 |
2 files changed, 14 insertions, 7 deletions
diff --git a/lib/yahns/queue_epoll.rb b/lib/yahns/queue_epoll.rb index 9e4271a..a198fbf 100644 --- a/lib/yahns/queue_epoll.rb +++ b/lib/yahns/queue_epoll.rb @@ -32,6 +32,10 @@ class Yahns::Queue < SleepyPenguin::Epoll::IO # :nodoc: epoll_ctl(Epoll::CTL_MOD, io, flags) end + def queue_del(io) + epoll_ctl(Epoll::CTL_DEL, io, 0) + end + def thr_init Thread.current[:yahns_rbuf] = ''.dup Thread.current[:yahns_fdmap] = @fdmap diff --git a/lib/yahns/server.rb b/lib/yahns/server.rb index 208b5ee..74eeb7e 100644 --- a/lib/yahns/server.rb +++ b/lib/yahns/server.rb @@ -438,25 +438,28 @@ class Yahns::Server # :nodoc: # This just injects the QueueQuitter object which acts like a # monkey wrench thrown into a perfectly good engine :) def quit_finish - quitter = Yahns::QueueQuitter.new + # we must not let quitters get GC-ed if we have any worker threads leftover + @quitter = Yahns::QueueQuitter.new # throw the monkey wrench into the worker threads - @queues.each { |q| q.queue_add(quitter, Yahns::Queue::QEV_QUIT) } + @queues.each { |q| q.queue_add(@quitter, Yahns::Queue::QEV_QUIT) } # watch the monkey wrench destroy all the threads! # Ugh, this may fail if we have dedicated threads trickling # response bodies out (e.g. "tail -F") Oh well, have a timeout begin @wthr.delete_if { |t| t.join(0.01) } + # Workaround Linux 5.5+ bug (fixed in 5.13+) + # https://yhbt.net/lore/lkml/20210405231025.33829-1-dave@stgolabs.net/ + @wthr[0] && @queues[0].respond_to?(:queue_del) and @queues.each do |q| + q.queue_del(@quitter) + q.queue_add(@quitter, Yahns::Queue::QEV_QUIT) + end end while @wthr[0] && Yahns.now <= @shutdown_expire # cleanup, our job is done @queues.each(&:close).clear - - # we must not let quitter get GC-ed if we have any worker threads leftover - @quitter = quitter - - quitter.close + @quitter.close # keep object around in case @wthr isn't empty rescue => e Yahns::Log.exception(@logger, "quit finish", e) ensure |