net,child_process: improve naming in internal code

All of this code is internal-only, and the changed variables/methods
are not generally useful to userland code.

When backporting this to release branches, it might be appropriate to
add non-enumerable aliases to be 100 % sure.

PR-URL: nodejs#14449
Reviewed-By: Alexey Orlenko <eaglexrlnk@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

doc/api/deprecations.md

@@ -634,6 +634,17 @@ Type: Runtime
 
 *Note*: change was made while `async_hooks` was an experimental API.
 
+<a id="DEP00XX"></a>
+### DEP00XX: Several internal properties of net.Server
+
+Type: Runtime
+
+Accessing several internal, undocumented properties of `net.Server` instances
+with inappropriate names has been deprecated.
+
+*Note*: As the original API was undocumented and not generally useful for
+non-internal code, no replacement API is provided.
+
 [`Buffer.allocUnsafeSlow(size)`]: buffer.html#buffer_class_method_buffer_allocunsafeslow_size
 [`Buffer.from(array)`]: buffer.html#buffer_class_method_buffer_from_array
 [`Buffer.from(buffer)`]: buffer.html#buffer_class_method_buffer_from_buffer

lib/internal/child_process.js

@@ -63,16 +63,16 @@ const handleConversion = {
 
       // if the socket was created by net.Server
       if (socket.server) {
-        // the slave should keep track of the socket
+        // the worker should keep track of the socket
         message.key = socket.server._connectionKey;
 
         var firstTime = !this.channel.sockets.send[message.key];
         var socketList = getSocketList('send', this, message.key);
 
         // the server should no longer expose a .connection property
         // and when asked to close it should query the socket status from
-        // the slaves
-        if (firstTime) socket.server._setupSlave(socketList);
+        // the workers
+        if (firstTime) socket.server._setupWorker(socketList);
 
         // Act like socket is detached
         if (!options.keepOpen)
@@ -911,12 +911,12 @@ function _validateStdio(stdio, sync) {
 }
 
 
-function getSocketList(type, slave, key) {
-  var sockets = slave.channel.sockets[type];
+function getSocketList(type, worker, key) {
+  var sockets = worker.channel.sockets[type];
   var socketList = sockets[key];
   if (!socketList) {
     var Construct = type === 'send' ? SocketListSend : SocketListReceive;
-    socketList = sockets[key] = new Construct(slave, key);
+    socketList = sockets[key] = new Construct(worker, key);
   }
   return socketList;
 }
@@ -958,6 +958,5 @@ module.exports = {
   ChildProcess,
   setupChannel,
   _validateStdio,
-  getSocketList,
   spawnSync
 };

lib/net.js

@@ -1187,7 +1187,7 @@ function Server(options, connectionListener) {
   Object.defineProperty(this, 'connections', {
     get: internalUtil.deprecate(() => {
 
-      if (this._usingSlaves) {
+      if (this._usingWorkers) {
         return null;
       }
       return this._connections;
@@ -1201,8 +1201,8 @@ function Server(options, connectionListener) {
 
   this[async_id_symbol] = -1;
   this._handle = null;
-  this._usingSlaves = false;
-  this._slaves = [];
+  this._usingWorkers = false;
+  this._workers = [];
   this._unref = false;
 
   this.allowHalfOpen = options.allowHalfOpen || false;
@@ -1555,13 +1555,13 @@ Server.prototype.getConnections = function(cb) {
     nextTick(asyncId, cb, err, connections);
   }
 
-  if (!this._usingSlaves) {
+  if (!this._usingWorkers) {
     end(null, this._connections);
     return this;
   }
 
-  // Poll slaves
-  var left = this._slaves.length;
+  // Poll workers
+  var left = this._workers.length;
   var total = this._connections;
 
   function oncount(err, count) {
@@ -1574,8 +1574,8 @@ Server.prototype.getConnections = function(cb) {
     if (--left === 0) return end(null, total);
   }
 
-  for (var n = 0; n < this._slaves.length; n++) {
-    this._slaves[n].getConnections(oncount);
+  for (var n = 0; n < this._workers.length; n++) {
+    this._workers[n].getConnections(oncount);
   }
 
   return this;
@@ -1598,22 +1598,22 @@ Server.prototype.close = function(cb) {
     this._handle = null;
   }
 
-  if (this._usingSlaves) {
-    var left = this._slaves.length;
-    const onSlaveClose = () => {
+  if (this._usingWorkers) {
+    var left = this._workers.length;
+    const onWorkerClose = () => {
       if (--left !== 0) return;
 
       this._connections = 0;
       this._emitCloseIfDrained();
     };
 
     // Increment connections to be sure that, even if all sockets will be closed
-    // during polling of slaves, `close` event will be emitted only once.
+    // during polling of workers, `close` event will be emitted only once.
     this._connections++;
 
-    // Poll slaves
-    for (var n = 0; n < this._slaves.length; n++)
-      this._slaves[n].close(onSlaveClose);
+    // Poll workers
+    for (var n = 0; n < this._workers.length; n++)
+      this._workers[n].close(onWorkerClose);
   } else {
     this._emitCloseIfDrained();
   }
@@ -1646,9 +1646,9 @@ Server.prototype.listenFD = internalUtil.deprecate(function(fd, type) {
 }, 'Server.listenFD is deprecated. Use Server.listen({fd: <number>}) instead.',
                                                    'DEP0021');
 
-Server.prototype._setupSlave = function(socketList) {
-  this._usingSlaves = true;
-  this._slaves.push(socketList);
+Server.prototype._setupWorker = function(socketList) {
+  this._usingWorkers = true;
+  this._workers.push(socketList);
 };
 
 Server.prototype.ref = function() {
@@ -1693,6 +1693,34 @@ if (process.platform === 'win32') {
   _setSimultaneousAccepts = function(handle) {};
 }
 
+// TODO(addaleax): Remove these after the Node 9.x branch cut.
+Object.defineProperty(Server.prototype, '_usingSlaves', {
+  get: internalUtil.deprecate(function() {
+    return this._usingWorkers;
+  }, 'Accessing internal properties of net.Server is deprecated.', 'DEP00XX'),
+  set: internalUtil.deprecate((val) => {
+    this._usingWorkers = val;
+  }, 'Accessing internal properties of net.Server is deprecated.', 'DEP00XX'),
+  configurable: true, enumerable: false
+});
+
+Object.defineProperty(Server.prototype, '_slaves', {
+  get: internalUtil.deprecate(function() {
+    return this._workers;
+  }, 'Accessing internal properties of net.Server is deprecated.', 'DEP00XX'),
+  set: internalUtil.deprecate((val) => {
+    this._workers = val;
+  }, 'Accessing internal properties of net.Server is deprecated.', 'DEP00XX'),
+  configurable: true, enumerable: false
+});
+
+Object.defineProperty(Server.prototype, '_setupSlave', {
+  value: internalUtil.deprecate(function(socketList) {
+    return this._setupWorker(socketList);
+  }, 'Accessing internal properties of net.Server is deprecated.', 'DEP00XX'),
+  configurable: true, enumerable: false
+});
+
 module.exports = {
   _createServerHandle: createServerHandle,
   _normalizeArgs: normalizeArgs,