Do not cache Socket.ip_address_list

shioimm · shioimm · commit a3d7056591c1 · 2024-02-15T14:17:02.000+09:00
As mentioned in the comment at #9374 (comment), caching Socket.ip_address_list does not follow changes in network configuration. But if we stop caching, it becomes necessary to check every time `Socket.tcp` is called whether it's a single stack or not, which could further degrade performance in the case of a dual stack. From this, I've changed the approach so that when a domain name is passed, it doesn't check whether it's a single stack or not and resolves names in parallel each time. The performance measurement results are as follows. require 'socket' require 'benchmark' HOSTNAME = "www.ruby-lang.org" PORT = 80 ai = Addrinfo.tcp(HOSTNAME, PORT) Benchmark.bmbm do |x| x.report("Domain name") do 30.times { Socket.tcp(HOSTNAME, PORT).close } end x.report("IP Address") do 30.times { Socket.tcp(ai.ip_address, PORT).close } end x.report("fast_fallback: false") do 30.times { Socket.tcp(HOSTNAME, PORT, fast_fallback: false).close } end end user system total real Domain name 0.004085 0.011873 0.015958 ( 0.330097) IP Address 0.000993 0.004400 0.005393 ( 0.257286) fast_fallback: false 0.001348 0.008266 0.009614 ( 0.298626)
diff --git a/ext/socket/lib/socket.rb b/ext/socket/lib/socket.rb
@@ -621,25 +621,8 @@ def accept_nonblock(exception: true)
 
   class << self
     attr_accessor :tcp_fast_fallback
-
-    def initialize_socket
-      @local_ip_address_list = Socket.ip_address_list
-      @has_public_ipv4_addr = false
-      @has_public_ipv6_addr = false
-      @local_ip_address_list.each do |ai|
-        if ai.ipv6?
-          next if @has_public_ipv6_addr
-          @has_public_ipv6_addr = true unless (ai.ipv6_loopback? || ai.ipv6_multicast? || ai.ipv6_linklocal?)
-        else
-          next if @has_public_ipv4_addr
-          @has_public_ipv4_addr = true unless (ai.ipv4_loopback? || ai.ipv4_multicast? || ai.ip_address.start_with?("169.254"))
-        end
-      end
-    end
   end
 
-  self.initialize_socket
-
   # :call-seq:
   #   Socket.tcp(host, port, local_host=nil, local_port=nil, [opts]) {|socket| ... }
   #   Socket.tcp(host, port, local_host=nil, local_port=nil, [opts])
@@ -699,15 +682,7 @@ def self.tcp(host, port, local_host = nil, local_port = nil, connect_timeout: ni
     ret = loop do
       case state
       when :start
-        specified_family_name, next_state =
-          (host && specified_family_name_and_next_state(host)) ||
-          ((host == "localhost" || host.nil?) &&
-           @local_ip_address_list.none?(&:ipv6_loopback?) ? [:ipv4, :v4c] : nil ) ||
-          ((host != "localhost" && !host.nil?) &&
-           (if @has_public_ipv4_addr && @has_public_ipv6_addr then nil
-            elsif @has_public_ipv4_addr then [:ipv4, :v4c]
-            elsif @has_public_ipv6_addr then [:ipv6, :v6c]
-            end))
+        specified_family_name, next_state = host && specified_family_name_and_next_state(host)
 
         if local_host && local_port
           specified_family_name, next_state = specified_family_name_and_next_state(local_host) unless specified_family_name
