worker: implement SHARE_ENV. see nodejs/node#26544.

README.md

@@ -78,6 +78,7 @@ Some caveats for the `child_process` backend:
   do not hold event loop references (`ref()` and `unref()` are noops).
 - Prior to node 10, objects like `Proxy`s can be serialized and cloned as they
   cannot be detected from regular javascript.
+- `SHARE_ENV` does not work and will throw an error if passed.
 
 Caveats for the `web_workers` backend:
 
@@ -102,6 +103,7 @@ Caveats for the `web_workers` backend:
   depending on your `Content-Security-Policy`.
 - `FileList` will emerge on the other side as an `Array` rather than a
   `FileList` when sent as `workerData`.
+- `SHARE_ENV` does not work and will throw an error if passed.
 
 Caveats for the `polyfill` backend:
 

lib/browser/env.js

@@ -29,6 +29,7 @@ function parseEnv(name) {
       WORKER_DATA: undefined,
       WORKER_STDIN: false,
       WORKER_EVAL: false,
+      WORKER_ENV: {},
       WORKER_BOOTSTRAP: null
     };
   }
@@ -38,7 +39,8 @@ function parseEnv(name) {
     WORKER_DATA: items[1],
     WORKER_STDIN: items[2],
     WORKER_EVAL: items[3],
-    WORKER_BOOTSTRAP: items[4]
+    WORKER_ENV: items[4],
+    WORKER_BOOTSTRAP: items[5]
   };
 }
 

lib/browser/main.js

@@ -23,6 +23,7 @@ exports.MessagePort = MessagePortBase;
 exports.MessageChannel = MessageChannel;
 exports.Worker = Worker;
 exports.moveMessagePortToContext = null;
+exports.SHARE_ENV = Symbol.for('nodejs.worker_threads.SHARE_ENV');
 exports.importScripts = null;
 
 exports.backend = backend.polyfill ? 'polyfill' : 'web_workers';

lib/browser/parent.js

@@ -40,6 +40,7 @@ const {
   WORKER_ID,
   WORKER_DATA,
   WORKER_STDIN,
+  WORKER_ENV,
   WORKER_EVAL
 } = env;
 
@@ -138,6 +139,9 @@ class Parent extends MessagePortBase {
     process.stderr = this._stderr;
 
     injectConsole(this._console);
+
+    for (const key of Object.keys(WORKER_ENV))
+      process.env[key] = WORKER_ENV[key];
   }
 
   _handleMessage(event) {

lib/browser/thread.js

@@ -25,6 +25,7 @@ exports.MessagePort = MessagePortBase;
 exports.MessageChannel = MessageChannel;
 exports.Worker = Worker;
 exports.moveMessagePortToContext = null;
+exports.SHARE_ENV = Symbol.for('nodejs.worker_threads.SHARE_ENV');
 exports.importScripts = importScripts;
 
 exports.backend = backend.polyfill ? 'polyfill' : 'web_workers';

lib/browser/worker.js

@@ -49,6 +49,8 @@ const DEFAULT_BOOTSTRAP_URL =
 
 const BOOTSTRAP_URL = env.WORKER_BOOTSTRAP || DEFAULT_BOOTSTRAP_URL;
 
+const SHARE_ENV = Symbol.for('nodejs.worker_threads.SHARE_ENV');
+
 let uid = 1;
 
 /**
@@ -68,6 +70,13 @@ class Worker extends EventEmitter {
     if (typeof options !== 'object')
       throw new ArgError('options', options, 'object');
 
+    if (options.env != null
+        && typeof options.env !== 'object'
+        && options.env !== SHARE_ENV) {
+      throw new ArgError('env', options.env,
+                        ['object', 'worker_threads.SHARE_ENV']);
+    }
+
     if (options.type != null && typeof options.type !== 'string')
       throw new ArgError('type', options.type, 'string');
 
@@ -98,6 +107,9 @@ class Worker extends EventEmitter {
     let code = null;
     let type = options.type;
 
+    if (options.env === SHARE_ENV)
+      throw new WorkerError(errors.NO_SHARE_ENV);
+
     if (options.eval) {
       if (type === 'module')
         throw new WorkerError(errors.ES_MODULE, 'eval');
@@ -125,6 +137,7 @@ class Worker extends EventEmitter {
         options.workerData,
         Boolean(options.stdin),
         Boolean(options.eval),
+        options.env || process.env,
         options.bootstrap || env.WORKER_BOOTSTRAP
       ])
     });

lib/internal/utils.js

@@ -130,6 +130,11 @@ const errors = {
     'Invalid port number (%s).'
   ],
 
+  NO_SHARE_ENV: [
+    'ERR_SHARE_ENV_NOT_SUPPORTED',
+    'SHARE_ENV is not supported on this backend.'
+  ],
+
   // High Level Worker Errors
   BLACKLIST: ['ERR_WORKER_BLACKLIST', 'Cannot bind blacklisted event: "%s".'],
   FATAL_ERROR: ['ERR_WORKER_FATAL_ERROR', 'Fatal exception.'],

lib/process/main.js

@@ -19,6 +19,7 @@ exports.MessagePort = MessagePortBase;
 exports.MessageChannel = MessageChannel;
 exports.Worker = Worker;
 exports.moveMessagePortToContext = null;
+exports.SHARE_ENV = Symbol.for('nodejs.worker_threads.SHARE_ENV');
 exports.importScripts = null;
 
 exports.backend = 'child_process';

lib/process/thread.js

@@ -25,6 +25,7 @@ exports.MessagePort = MessagePortBase;
 exports.MessageChannel = MessageChannel;
 exports.Worker = Worker;
 exports.moveMessagePortToContext = null;
+exports.SHARE_ENV = Symbol.for('nodejs.worker_threads.SHARE_ENV');
 exports.importScripts = null;
 
 exports.backend = 'child_process';

lib/process/worker.js

@@ -55,6 +55,8 @@ const {
 
 const children = new Set();
 
+const SHARE_ENV = Symbol.for('nodejs.worker_threads.SHARE_ENV');
+
 let uid = 1;
 let exitBound = false;
 let bundled = null;
@@ -76,6 +78,13 @@ class Worker extends EventEmitter {
     if (typeof options !== 'object')
       throw new ArgError('options', options, 'object');
 
+    if (options.env != null
+        && typeof options.env !== 'object'
+        && options.env !== SHARE_ENV) {
+      throw new ArgError('env', options.env,
+                        ['object', 'worker_threads.SHARE_ENV']);
+    }
+
     if (options.execArgv && !Array.isArray(options.execArgv))
       throw new ArgError('execArgv', options.execArgv, 'Array');
 
@@ -109,6 +118,9 @@ class Worker extends EventEmitter {
     const bin = process.execPath || process.argv[0];
     const args = [];
 
+    if (options.env === SHARE_ENV)
+      throw new WorkerError(errors.NO_SHARE_ENV);
+
     // Validate filename.
     if (!options.eval) {
       if (!isAbsolute(file)
@@ -229,9 +241,10 @@ class Worker extends EventEmitter {
     }
 
     // Setup options.
+    const env = options.env || process.env;
     const opt = {
       stdio: ['pipe', 'pipe', 'pipe'],
-      env: Object.assign(Object.create(null), process.env, {
+      env: Object.assign(Object.create(null), env, {
         BTHREADS_WORKER_ID: this.threadId.toString(10),
         BTHREADS_WORKER_DATA: encoding.stringify(options.workerData),
         BTHREADS_WORKER_STDIN: options.stdin ? '1' : '0',

lib/threads/index.js

@@ -34,6 +34,7 @@ exports.MessagePort = threads.MessagePort;
 exports.MessageChannel = threads.MessageChannel;
 exports.Worker = threads.Worker;
 exports.moveMessagePortToContext = threads.moveMessagePortToContext || null;
+exports.SHARE_ENV = threads.SHARE_ENV || null;
 exports.importScripts = null;
 
 exports.backend = 'worker_threads';