From 31ee6b4daa1da9cd02e75b27924b2729345e999d Mon Sep 17 00:00:00 2001 From: Eric Wong Date: Tue, 29 Dec 2009 12:59:01 -0800 Subject: quiet spurious wakeups for accept() in Thread* models Under all MRI 1.8, a blocking Socket#accept Ruby method (needs to[1]) translate to a non-blocking accept(2) system call that may wake up threads/processes unnecessarily. Unfortunately, we failed to trap and ignore EAGAIN in those cases. This issue did not affect Ruby 1.9 running under modern Linux kernels where a _blocking_ accept(2) system call is not (easily, at least) susceptible to spurious wakeups. Non-Linux systems running Ruby 1.9 may be affected. [1] - using a blocking accept(2) on a shared socket with green threads is dangerous, as noted in commit ee7fe220ccbc991e1e7cbe982caf48e3303274c7 (and commit 451ca6997b4f298b436605b7f0af75f369320425) --- lib/rainbows/thread_spawn.rb | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'lib/rainbows/thread_spawn.rb') diff --git a/lib/rainbows/thread_spawn.rb b/lib/rainbows/thread_spawn.rb index eb3ca75..75cc150 100644 --- a/lib/rainbows/thread_spawn.rb +++ b/lib/rainbows/thread_spawn.rb @@ -34,8 +34,8 @@ module Rainbows # unlikely one. Since this case is (or should be) uncommon, # just busy wait when we have to. sleep(0.01) - else - klass.new(l.accept) do |c| + elsif c = Rainbows.sync_accept(l) + klass.new(c) do |c| begin lock.synchronize { G.cur += 1 } process_client(c) @@ -44,7 +44,6 @@ module Rainbows end end end - rescue Errno::EINTR, Errno::ECONNABORTED rescue => e Error.listen_loop(e) end while G.alive -- cgit v1.2.3-24-ge0c7