diff options
| -rw-r--r-- | lib/net/ssh/ruby_compat.rb | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/lib/net/ssh/ruby_compat.rb b/lib/net/ssh/ruby_compat.rb index 2fa2a9b..8a1c8f2 100644 --- a/lib/net/ssh/ruby_compat.rb +++ b/lib/net/ssh/ruby_compat.rb @@ -14,9 +14,9 @@ module Net; module SSH # for different ruby implementations. class Compat - # A workaround for an IO#select threading bug in MRI 1.8. + # A workaround for an IO#select threading bug in certain versions of MRI 1.8. # See: http://net-ssh.lighthouseapp.com/projects/36253/tickets/1-ioselect-threading-bug-in-ruby-18 - # Also: http://redmine.ruby-lang.org/issues/show/1993 + # The root issue is documented here: http://redmine.ruby-lang.org/issues/show/1993 if RUBY_VERSION >= '1.9' || RUBY_PLATFORM == 'java' def self.io_select(*params) IO.select(*params) @@ -24,7 +24,15 @@ module Net; module SSH else SELECT_MUTEX = Mutex.new def self.io_select(*params) - SELECT_MUTEX.synchronize do + # It should be safe to wrap calls in a mutex when the timeout is 0 + # (that is, the call is not supposed to block). + # We leave blocking calls unprotected to avoid causing deadlocks. + # This should still catch the main case for Capistrano users. + if params[3] == 0 + SELECT_MUTEX.synchronize do + IO.select(*params) + end + else IO.select(*params) end end |