socket: avoid common exceptions when calling connect_nonblock

Errno::EISCONN and IO::WaitReadable exceptions are common,
expensive, and noisy under normal use.  Avoid raising on them
since they are not exceptional.

* ext/socket/lib/socket.rb (connect_internal): avoid common exceptions
  from connect_nonblock. [ruby-core:68909]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@50363 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 5 insertions, 8 deletions

diff --git a/ext/socket/lib/socket.rb b/ext/socket/lib/socket.rb
index 2cd7aeadf9..2723f7b78c 100644
--- a/ext/socket/lib/socket.rb
+++ b/ext/socket/lib/socket.rb
@@ -50,17 +50,14 @@ class Addrinfo
       sock.ipv6only! if self.ipv6?
       sock.bind local_addrinfo if local_addrinfo
       if timeout
-        begin
-          sock.connect_nonblock(self)
-        rescue IO::WaitWritable
+        case sock.connect_nonblock(self, exception: false)
+        when 0 # success or EISCONN, other errors raise
+          break
+        when :wait_writable
           if !IO.select(nil, [sock], nil, timeout)
             raise Errno::ETIMEDOUT, 'user specified timeout'
           end
-          begin
-            sock.connect_nonblock(self) # check connection failure
-          rescue Errno::EISCONN
-          end
-        end
+        end while true
       else
         sock.connect(self)
       end