worker: initial implementation

Implement multi-threading support for most of the API.

PR-URL: #110
Reviewed-By: Stephen Belanger <admin@stephenbelanger.com>

.eslintrc.yaml

@@ -198,3 +198,4 @@ globals:
   LTTNG_NET_SERVER_CONNECTION: false
   LTTNG_NET_STREAM_END: false
   internalBinding: false
+  isMainThread: false

lib/domain.js

@@ -21,6 +21,11 @@
 
 'use strict';
 
+if (!isMainThread) {
+  const errors = require('internal/errors');
+  throw new errors.TypeError('ERR_WORKER_DOMAIN');
+}
+
 // WARNING: THIS MODULE IS PENDING DEPRECATION.
 //
 // No new pull requests targeting this module will be accepted

lib/internal/bootstrap_node.js

@@ -9,6 +9,7 @@
 
 (function(process) {
   let internalBinding;
+  let isMainThread;
 
   function startup() {
     const EventEmitter = NativeModule.require('events');
@@ -24,6 +25,8 @@
     internalBinding = process._internalBinding;
     delete process._internalBinding;
 
+    isMainThread = internalBinding('worker').threadId === 0;
+
     // do this good and early, since it handles errors.
     setupProcessFatal();
 
@@ -69,7 +72,7 @@
 
     // Do not initialize channel in debugger agent, it deletes env variable
     // and the main thread won't see it.
-    if (process.argv[1] !== '--debug-agent')
+    if (process.argv[1] !== '--debug-agent' && isMainThread)
       _process.setupChannel();
 
     _process.setupRawDebug();
@@ -110,8 +113,11 @@
     // are running from a script and running the REPL - but there are a few
     // others like the debugger or running --eval arguments. Here we decide
     // which mode we run in.
-
-    if (NativeModule.exists('_third_party_main')) {
+    if (internalBinding('worker').getEnvMessagePort() !== undefined) {
+      // This means we are in a Worker context, and any script execution
+      // will be directed by the worker module.
+      NativeModule.require('internal/worker').setupChild(evalScript);
+    } else if (NativeModule.exists('_third_party_main')) {
       // To allow people to extend Node in different ways, this hook allows
       // one to drop a file lib/_third_party_main.js into the build
       // directory which will be executed instead of Node's normal loading.
@@ -279,18 +285,20 @@
       }, `'${name}' is deprecated, use 'global'`, 'DEP0016');
     }
 
-    Object.defineProperties(global, {
-      GLOBAL: {
-        configurable: true,
-        get: makeGetter('GLOBAL'),
-        set: makeSetter('GLOBAL')
-      },
-      root: {
-        configurable: true,
-        get: makeGetter('root'),
-        set: makeSetter('root')
-      }
-    });
+    if (isMainThread) {
+      Object.defineProperties(global, {
+        GLOBAL: {
+          configurable: true,
+          get: makeGetter('GLOBAL'),
+          set: makeSetter('GLOBAL')
+        },
+        root: {
+          configurable: true,
+          get: makeGetter('root'),
+          set: makeSetter('root')
+        }
+      });
+    }
 
     global.Buffer = NativeModule.require('buffer').Buffer;
     process.domain = null;
@@ -446,15 +454,14 @@
     return `process.binding('inspector').callAndPauseOnStart(${fn}, {})`;
   }
 
-  function evalScript(name) {
+  function evalScript(name, body = wrapForBreakOnFirstLine(process._eval)) {
     const Module = NativeModule.require('module');
     const path = NativeModule.require('path');
     const cwd = tryGetCwd(path);
 
     const module = new Module(name);
     module.filename = path.join(cwd, name);
     module.paths = Module._nodeModulePaths(cwd);
-    const body = wrapForBreakOnFirstLine(process._eval);
     const script = `global.__filename = ${JSON.stringify(name)};\n` +
                    'global.exports = exports;\n' +
                    'global.module = module;\n' +
@@ -578,7 +585,7 @@
   };
 
   NativeModule.wrapper = [
-    '(function (exports, require, module, internalBinding) {',
+    '(function (exports, require, module, internalBinding, isMainThread) {',
     '\n});'
   ];
 
@@ -594,7 +601,11 @@
         lineOffset: 0,
         displayErrors: true
       });
-      fn(this.exports, NativeModule.require, this, internalBinding);
+      fn(this.exports,
+         NativeModule.require,
+         this,
+         internalBinding,
+         isMainThread);
 
       this.loaded = true;
     } finally {

lib/internal/errors.js

@@ -351,6 +351,12 @@ E('ERR_VALID_PERFORMANCE_ENTRY_TYPE',
 E('ERR_VALUE_OUT_OF_RANGE', (start, end, value) => {
   return `The value of "${start}" must be ${end}. Received "${value}"`;
 });
+E('ERR_WORKER_DOMAIN', 'Domains are not available inside worker threads');
+E('ERR_WORKER_NEED_ABSOLUTE_PATH',
+  'The worker script filename must be an absolute path. Received "%s"');
+E('ERR_WORKER_OUT_OF_MEMORY', 'The worker script ran out of memory');
+E('ERR_WORKER_UNSERIALIZABLE_ERROR',
+  'Serializing an uncaught exception failed');
 E('ERR_ZLIB_BINDING_CLOSED', 'zlib binding closed');
 
 function invalidArgType(name, expected, actual) {

lib/internal/process/stdio.js

@@ -11,6 +11,7 @@ function setupStdio() {
 
   function getStdout() {
     if (stdout) return stdout;
+    if (!isMainThread) return null;
     stdout = createWritableStdioStream(1);
     stdout.destroySoon = stdout.destroy;
     stdout._destroy = function(er, cb) {
@@ -26,6 +27,7 @@ function setupStdio() {
 
   function getStderr() {
     if (stderr) return stderr;
+    if (!isMainThread) return null;
     stderr = createWritableStdioStream(2);
     stderr.destroySoon = stderr.destroy;
     stderr._destroy = function(er, cb) {
@@ -41,6 +43,7 @@ function setupStdio() {
 
   function getStdin() {
     if (stdin) return stdin;
+    if (!isMainThread) return null;
 
     const tty_wrap = process.binding('tty_wrap');
     const fd = 0;