socket: avoid arg parsing in rsock_s_accept_nonblock

* ext/socket/init.c (rsock_s_accept_nonblock): avoid parsing args
  [ruby-core:71439] [Feature #11339]
* ext/socket/rubysocket.h: adjust prototype
* ext/socket/socket.c (sock_accept_nonblock): make private
* ext/socket/tcpserver.c (tcp_accept_nonblock): ditto
* ext/socket/unixserver.c (unix_accept_nonblock): ditto
* ext/socket/lib/socket.rb (Socket#accept_nonblock):
  implement as wrapper, move RDoc
  (TCPServer#accept_nonblock): ditto
  (UNIXServer#accept_nonblock): ditto

target 0: a (ruby 2.3.0dev (2015-11-12 trunk 52550) [x86_64-linux])
target 1: b (ruby 2.3.0dev (2015-11-12 avoid-kwarg-capi 52550) [x86_64-linux]

-----------------------------------------------------------
accept_nonblock

require 'tempfile'
require 'socket'
require 'io/wait'
nr = 500000
Tempfile.create(%w(accept_nonblock .sock)) do |tmp|
  path = tmp.path
  File.unlink(path)
  s = UNIXServer.new(path)
  addr = Socket.sockaddr_un(path).freeze
  nr.times do
    s.accept_nonblock(exception: false)
    c = UNIXSocket.new(path)
    s.wait_readable
    s.accept_nonblock(exception: false).close
    c.close
  end
end

-----------------------------------------------------------
raw data:

[["accept_nonblock",
  [[4.807877402752638,
    4.930681671947241,
    4.738454818725586,
    4.69268161803484,
    4.684675686061382],
   [4.253904823213816,
    4.255124930292368,
    4.295955188572407,
    4.248479191213846,
    4.213303029537201]]]]

Elapsed time: 45.123040065 (sec)
-----------------------------------------------------------
benchmark results:
minimum results in each 5 measurements.
Execution time (sec)
name            a       b
accept_nonblock   4.685   4.213

Speedup ratio: compare with the result of `a' (greater is better)
name            b
accept_nonblock   1.112

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52601 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 140 insertions, 0 deletions

diff --git a/ext/socket/lib/socket.rb b/ext/socket/lib/socket.rb
index 86da09e997..fed1d43e34 100644
--- a/ext/socket/lib/socket.rb
+++ b/ext/socket/lib/socket.rb
@@ -398,6 +398,63 @@ class Socket < BasicSocket
     __recvfrom_nonblock(len, flag, str, exception)
   end
 
+  # call-seq:
+  #   socket.accept_nonblock([options]) => [client_socket, client_addrinfo]
+  #
+  # Accepts an incoming connection using accept(2) after
+  # O_NONBLOCK is set for the underlying file descriptor.
+  # It returns an array containing the accepted socket
+  # for the incoming connection, _client_socket_,
+  # and an Addrinfo, _client_addrinfo_.
+  #
+  # === Example
+  #   # In one script, start this first
+  #   require 'socket'
+  #   include Socket::Constants
+  #   socket = Socket.new(AF_INET, SOCK_STREAM, 0)
+  #   sockaddr = Socket.sockaddr_in(2200, 'localhost')
+  #   socket.bind(sockaddr)
+  #   socket.listen(5)
+  #   begin # emulate blocking accept
+  #     client_socket, client_addrinfo = socket.accept_nonblock
+  #   rescue IO::WaitReadable, Errno::EINTR
+  #     IO.select([socket])
+  #     retry
+  #   end
+  #   puts "The client said, '#{client_socket.readline.chomp}'"
+  #   client_socket.puts "Hello from script one!"
+  #   socket.close
+  #
+  #   # In another script, start this second
+  #   require 'socket'
+  #   include Socket::Constants
+  #   socket = Socket.new(AF_INET, SOCK_STREAM, 0)
+  #   sockaddr = Socket.sockaddr_in(2200, 'localhost')
+  #   socket.connect(sockaddr)
+  #   socket.puts "Hello from script 2."
+  #   puts "The server said, '#{socket.readline.chomp}'"
+  #   socket.close
+  #
+  # Refer to Socket#accept for the exceptions that may be thrown if the call
+  # to _accept_nonblock_ fails.
+  #
+  # Socket#accept_nonblock may raise any error corresponding to accept(2) failure,
+  # including Errno::EWOULDBLOCK.
+  #
+  # If the exception is Errno::EWOULDBLOCK, Errno::EAGAIN, Errno::ECONNABORTED or Errno::EPROTO,
+  # it is extended by IO::WaitReadable.
+  # So IO::WaitReadable can be used to rescue the exceptions for retrying accept_nonblock.
+  #
+  # By specifying `exception: false`, the options hash allows you to indicate
+  # that accept_nonblock should not raise an IO::WaitReadable exception, but
+  # return the symbol :wait_readable instead.
+  #
+  # === See
+  # * Socket#accept
+  def accept_nonblock(exception: true)
+    __accept_nonblock(exception)
+  end
+
   # :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])
@@ -1086,3 +1143,86 @@ class UDPSocket < IPSocket
     __recvfrom_nonblock(len, flag, str, exception)
   end
 end
+
+class TCPServer < TCPSocket
+
+  # call-seq:
+  #   tcpserver.accept_nonblock([options]) => tcpsocket
+  #
+  # Accepts an incoming connection using accept(2) after
+  # O_NONBLOCK is set for the underlying file descriptor.
+  # It returns an accepted TCPSocket for the incoming connection.
+  #
+  # === Example
+  # 	require 'socket'
+  # 	serv = TCPServer.new(2202)
+  # 	begin # emulate blocking accept
+  # 	  sock = serv.accept_nonblock
+  # 	rescue IO::WaitReadable, Errno::EINTR
+  # 	  IO.select([serv])
+  # 	  retry
+  # 	end
+  # 	# sock is an accepted socket.
+  #
+  # Refer to Socket#accept for the exceptions that may be thrown if the call
+  # to TCPServer#accept_nonblock fails.
+  #
+  # TCPServer#accept_nonblock may raise any error corresponding to accept(2) failure,
+  # including Errno::EWOULDBLOCK.
+  #
+  # If the exception is Errno::EWOULDBLOCK, Errno::EAGAIN, Errno::ECONNABORTED, Errno::EPROTO,
+  # it is extended by IO::WaitReadable.
+  # So IO::WaitReadable can be used to rescue the exceptions for retrying accept_nonblock.
+  #
+  # By specifying `exception: false`, the options hash allows you to indicate
+  # that accept_nonblock should not raise an IO::WaitReadable exception, but
+  # return the symbol :wait_readable instead.
+  #
+  # === See
+  # * TCPServer#accept
+  # * Socket#accept
+  def accept_nonblock(exception: true)
+    __accept_nonblock(exception)
+  end
+end
+
+class UNIXServer < UNIXSocket
+  # call-seq:
+  #   unixserver.accept_nonblock([options]) => unixsocket
+  #
+  # Accepts an incoming connection using accept(2) after
+  # O_NONBLOCK is set for the underlying file descriptor.
+  # It returns an accepted UNIXSocket for the incoming connection.
+  #
+  # === Example
+  # 	require 'socket'
+  # 	serv = UNIXServer.new("/tmp/sock")
+  # 	begin # emulate blocking accept
+  # 	  sock = serv.accept_nonblock
+  # 	rescue IO::WaitReadable, Errno::EINTR
+  # 	  IO.select([serv])
+  # 	  retry
+  # 	end
+  # 	# sock is an accepted socket.
+  #
+  # Refer to Socket#accept for the exceptions that may be thrown if the call
+  # to UNIXServer#accept_nonblock fails.
+  #
+  # UNIXServer#accept_nonblock may raise any error corresponding to accept(2) failure,
+  # including Errno::EWOULDBLOCK.
+  #
+  # If the exception is Errno::EWOULDBLOCK, Errno::EAGAIN, Errno::ECONNABORTED or Errno::EPROTO,
+  # it is extended by IO::WaitReadable.
+  # So IO::WaitReadable can be used to rescue the exceptions for retrying accept_nonblock.
+  #
+  # By specifying `exception: false`, the options hash allows you to indicate
+  # that accept_nonblock should not raise an IO::WaitReadable exception, but
+  # return the symbol :wait_readable instead.
+  #
+  # === See
+  # * UNIXServer#accept
+  # * Socket#accept
+  def accept_nonblock(exception: true)
+    __accept_nonblock(exception)
+  end
+end