net: add pauseOnConnect option to createServer()

doc/api/net.markdown

@@ -13,14 +13,21 @@ automatically set as a listener for the ['connection'][] event.
 
 `options` is an object with the following defaults:
 
-    { allowHalfOpen: false
+    {
+      allowHalfOpen: false,
+      pauseOnConnect: false
     }
 
 If `allowHalfOpen` is `true`, then the socket won't automatically send a FIN
 packet when the other end of the socket sends a FIN packet. The socket becomes
 non-readable, but still writable. You should call the `end()` method explicitly.
 See ['end'][] event for more information.
 
+If `pauseOnConnect` is `true`, then the socket associated with each incoming
+connection will be paused, and no data will be read from its handle. This allows
+connections to be passed between processes without any data being read by the
+original process. To begin reading data from a paused socket, call `resume()`.
+
 Here is an example of an echo server which listens for connections
 on port 8124:
 

lib/net.js

@@ -180,8 +180,15 @@ function Socket(options) {
 
   // if we have a handle, then start the flow of data into the
   // buffer.  if not, then this will happen when we connect
-  if (this._handle && options.readable !== false)
-    this.read(0);
+  if (this._handle && options.readable !== false) {
+    if (options.pauseOnCreate) {
+      // stop the handle from reading and pause the stream
+      this._handle.reading = false;
+      this._handle.readStop();
+      this._readableState.flowing = false;
+    } else
+      this.read(0);
+  }
 }
 util.inherits(Socket, stream.Duplex);
 
@@ -1024,6 +1031,7 @@ function Server(options, connectionListener) {
   this._slaves = [];
 
   this.allowHalfOpen = options.allowHalfOpen || false;
+  this.pauseOnConnect = !!options.pauseOnConnect;
 }
 util.inherits(Server, events.EventEmitter);
 exports.Server = Server;
@@ -1287,7 +1295,8 @@ function onconnection(err, clientHandle) {
 
   var socket = new Socket({
     handle: clientHandle,
-    allowHalfOpen: self.allowHalfOpen
+    allowHalfOpen: self.allowHalfOpen,
+    pauseOnCreate: self.pauseOnConnect
   });
   socket.readable = socket.writable = true;
 

test/simple/test-net-server-pause-on-connect.js

@@ -0,0 +1,59 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+var common = require('../common');
+var assert = require('assert');
+var net = require('net');
+var msg = 'test';
+var stopped = true;
+var server1 = net.createServer({pauseOnConnect: true}, function(socket) {
+  socket.on('data', function(data) {
+    if (stopped) {
+      assert(false, 'data event should not happen');
+    }
+
+    assert.equal(data.toString(), msg, 'invalid data received');
+    socket.end();
+    server1.close();
+  });
+
+  setTimeout(function() {
+    assert.equal(socket.bytesRead, 0, 'no data should be read');
+    socket.resume();
+    stopped = false;
+  }, 3000);
+});
+
+var server2 = net.createServer({pauseOnConnect: false}, function(socket) {
+  socket.on('data', function(data) {
+    assert.equal(data.toString(), msg, 'invalid data received');
+    socket.end();
+    server2.close();
+  });
+});
+
+server1.listen(common.PORT, function() {
+  net.createConnection({port: common.PORT}).write(msg);
+});
+
+server2.listen(common.PORT + 1, function() {
+  net.createConnection({port: common.PORT + 1}).write(msg);
+});