net: persist net.Socket options before connect

Remembers net.Socket options called before connect and retroactively
applies them after the handle has been created.

This change makes the following function calls more user-friendly:

- setKeepAlive()
- setNoDelay()
- ref()
- unref()

Related: nodejs/node-v0.x-archive#7077 and
nodejs/node-v0.x-archive#8572

lib/net.js

@@ -121,6 +121,9 @@ function Socket(options) {
   this._hadError = false;
   this._handle = null;
   this._host = null;
+  this._unref = false;
+  this._setNoDelay = null;
+  this._setKeepAlive = null;
 
   if (typeof options === 'number')
     options = { fd: options }; // Legacy interface.
@@ -325,12 +328,16 @@ Socket.prototype.setNoDelay = function(enable) {
   // backwards compatibility: assume true when `enable` is omitted
   if (this._handle && this._handle.setNoDelay)
     this._handle.setNoDelay(enable === undefined ? true : !!enable);
+  else
+    this._setNoDelay = enable === undefined ? true : !!enable;
 };
 
 
 Socket.prototype.setKeepAlive = function(setting, msecs) {
   if (this._handle && this._handle.setKeepAlive)
     this._handle.setKeepAlive(setting, ~~(msecs / 1000));
+  else
+    this._setKeepAlive = [setting, ~~(msecs / 1000)];
 };
 
 
@@ -766,6 +773,14 @@ function connect(self, address, port, addressType, localAddress, localPort) {
 
   var err;
 
+  self.setNoDelay(self._setNoDelay);
+
+  if (self._setKeepAlive)
+    self.setKeepAlive(self._setKeepAlive[0], self._setKeepAlive[1]);
+
+  if (self._unref)
+    self.unref();
+
   if (localAddress || localPort) {
     var bind;
 
@@ -933,12 +948,16 @@ Socket.prototype.connect = function(options, cb) {
 
 
 Socket.prototype.ref = function() {
+  this._unref = false;
+
   if (this._handle)
     this._handle.ref();
 };
 
 
 Socket.prototype.unref = function() {
+  this._unref = true;
+
   if (this._handle)
     this._handle.unref();
 };

test/parallel/test-net-persistent-keepalive.js

@@ -0,0 +1,32 @@
+var common = require('../common');
+var assert = require('assert');
+var net = require('net');
+
+var serverConnection;
+var echoServer = net.createServer(function(connection) {
+  serverConnection = connection;
+  connection.setTimeout(0);
+  assert.notEqual(connection.setKeepAlive, undefined);
+  connection.on('end', function() {
+    connection.end();
+  });
+});
+echoServer.listen(common.PORT);
+
+echoServer.on('listening', function() {
+  var clientConnection = new net.Socket({});
+  // send a keepalive packet after 1000 ms
+  // and make sure it persists
+  clientConnection.setKeepAlive(true, 1000);
+  clientConnection.connect(common.PORT);
+  clientConnection.setTimeout(0);
+
+  setTimeout(function() {
+    // make sure both connections are still open
+    assert.equal(serverConnection.readyState, 'open');
+    assert.equal(clientConnection.readyState, 'open');
+    serverConnection.end();
+    clientConnection.end();
+    echoServer.close();
+  }, 1200);
+});

test/parallel/test-net-persistent-nodelay.js

@@ -0,0 +1,42 @@
+var common = require('../common');
+var assert = require('assert');
+var net = require('net');
+
+var serverConnection;
+var echoServer = net.createServer(function(connection) {
+  serverConnection = connection;
+  connection.end()
+});
+echoServer.listen(common.PORT);
+
+var setTrue = false;
+
+var Socket = net.Socket;
+
+Socket.prototype.setNoDelay = function(enable) {
+  if (this._handle && this._handle.setNoDelay) {
+    if (enable === undefined || !!enable) {
+      setTrue = true;
+    }
+    this._handle.setNoDelay(enable === undefined ? true : !!enable);
+  } else {
+    this._setNoDelay = enable === undefined ? true : !!enable;
+  }
+}
+
+echoServer.on('listening', function() {
+  var sock1 = new Socket({});
+  // setNoDelay before the handle is created
+  // there is probably a better way to test this
+
+  sock1.setNoDelay();
+  sock1.connect(common.PORT, function() {
+    var sock2 = new Socket({});
+    sock2.connect(common.PORT, function() {
+      assert.ok(setTrue);
+      setTimeout(function() {
+        echoServer.close();
+      }, 500);
+    });
+  });
+});