socket: avoid arg parsing in bsock_sendmsg_internal

* ext/socket/ancdata.c (bsock_sendmsg_internal): avoid arg parsing
  [ruby-core:71439] [Feature #11339]
  (rsock_bsock_sendmsg): make private, adjust for above
  (rsock_bsock_sendmsg_nonblock): ditto
* ext/socket/rubysocket.h: adjust prototypes
  (rsock_opt_false_p): remove
* ext/socket/basicsocket.c (rsock_init_basicsocket):
  define private methods
* ext/socket/lib/socket.rb (BasicSocket#sendmsg): new wrapper
  (BasicSocket#sendmsg_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]

-----------------------------------------------------------
sendmsg_nonblock

require 'socket'
nr = 1_000_000
i = 0
msg = '.'
buf = '.'
begin
  r, w = UNIXSocket.pair(:SEQPACKET)
  while i < nr
    i += 1
    w.sendmsg_nonblock(msg, exception: false)
    r.recv(1, 0, buf)
  end
ensure
  r.close
  w.close
end

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

[["sendmsg_nonblock",
  [[1.875997293740511,
    1.8452614955604076,
    1.8449317328631878,
    1.8418389447033405,
    1.869386937469244],
   [1.5175109766423702,
    1.4987873211503029,
    1.4989623799920082,
    1.47918451577425,
    1.5017359890043736]]]]

Elapsed time: 16.775453245 (sec)
-----------------------------------------------------------
benchmark results:
minimum results in each 5 measurements.
Execution time (sec)
name             a       b
sendmsg_nonblock   1.842   1.479

Speedup ratio: compare with the result of `a' (greater is better)
name             b
sendmsg_nonblock   1.245

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52603 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 50 insertions, 0 deletions

diff --git a/ext/socket/lib/socket.rb b/ext/socket/lib/socket.rb
index 9e85318c1b..705a0b8459 100644
--- a/ext/socket/lib/socket.rb
+++ b/ext/socket/lib/socket.rb
@@ -276,6 +276,56 @@ class BasicSocket < IO
   end
 
   # call-seq:
+  #    basicsocket.sendmsg(mesg, flags=0, dest_sockaddr=nil, *controls) => numbytes_sent
+  #
+  # sendmsg sends a message using sendmsg(2) system call in blocking manner.
+  #
+  # _mesg_ is a string to send.
+  #
+  # _flags_ is bitwise OR of MSG_* constants such as Socket::MSG_OOB.
+  #
+  # _dest_sockaddr_ is a destination socket address for connection-less socket.
+  # It should be a sockaddr such as a result of Socket.sockaddr_in.
+  # An Addrinfo object can be used too.
+  #
+  # _controls_ is a list of ancillary data.
+  # The element of _controls_ should be Socket::AncillaryData or
+  # 3-elements array.
+  # The 3-element array should contains cmsg_level, cmsg_type and data.
+  #
+  # The return value, _numbytes_sent_ is an integer which is the number of bytes sent.
+  #
+  # sendmsg can be used to implement send_io as follows:
+  #
+  #   # use Socket::AncillaryData.
+  #   ancdata = Socket::AncillaryData.int(:UNIX, :SOCKET, :RIGHTS, io.fileno)
+  #   sock.sendmsg("a", 0, nil, ancdata)
+  #
+  #   # use 3-element array.
+  #   ancdata = [:SOCKET, :RIGHTS, [io.fileno].pack("i!")]
+  #   sock.sendmsg("\0", 0, nil, ancdata)
+  def sendmsg(mesg, flags = 0, dest_sockaddr = nil, *controls)
+    __sendmsg(mesg, flags, dest_sockaddr, controls)
+  end
+
+  # call-seq:
+  #    basicsocket.sendmsg_nonblock(mesg, flags=0, dest_sockaddr=nil, *controls, opts={}) => numbytes_sent
+  #
+  # sendmsg_nonblock sends a message using sendmsg(2) system call in non-blocking manner.
+  #
+  # It is similar to BasicSocket#sendmsg
+  # but the non-blocking flag is set before the system call
+  # and it doesn't retry the system call.
+  #
+  # By specifying `exception: false`, the _opts_ hash allows you to indicate
+  # that sendmsg_nonblock should not raise an IO::WaitWritable exception, but
+  # return the symbol :wait_writable instead.
+  def sendmsg_nonblock(mesg, flags = 0, dest_sockaddr = nil, *controls,
+                       exception: true)
+    __sendmsg_nonblock(mesg, flags, dest_sockaddr, controls, exception)
+  end
+
+  # call-seq:
   # 	basicsocket.recv_nonblock(maxlen [, flags [, buf [, options ]]]) => mesg
   #
   # Receives up to _maxlen_ bytes from +socket+ using recvfrom(2) after