From f6cd4e3e5976ce9edccdb13933028bdc95d43df4 Mon Sep 17 00:00:00 2001
From: cjihrig <cjihrig@gmail.com>
Date: Tue, 15 Jan 2019 15:39:43 -0500
Subject: [PATCH] process: allow reading umask in workers
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Refs: https://github.com/nodejs/node/issues/25448
PR-URL: https://github.com/nodejs/node/pull/25526
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
---
 doc/api/errors.md                          |  5 +++++
 doc/api/process.md                         |  3 ++-
 lib/internal/bootstrap/node.js             |  4 ++++
 lib/internal/errors.js                     |  2 ++
 lib/internal/process/worker_thread_only.js | 21 ++++++++++++++++++++-
 src/node_process_methods.cc                |  7 ++++++-
 test/common/index.js                       |  9 ++++-----
 test/parallel/test-fs-write-file-sync.js   |  2 +-
 test/parallel/test-process-umask-mask.js   |  2 +-
 test/parallel/test-process-umask.js        | 11 +++++++++--
 10 files changed, 54 insertions(+), 12 deletions(-)

diff --git a/doc/api/errors.md b/doc/api/errors.md
index bb903ed0ee8c15..840ba9b85c12c2 100644
--- a/doc/api/errors.md
+++ b/doc/api/errors.md
@@ -1926,6 +1926,11 @@ All attempts at serializing an uncaught exception from a worker thread failed.
 The pathname used for the main script of a worker has an
 unknown file extension.
 
+<a id="ERR_WORKER_UNSUPPORTED_OPERATION"></a>
+### ERR_WORKER_UNSUPPORTED_OPERATION
+
+The requested functionality is not supported in worker threads.
+
 <a id="ERR_ZLIB_INITIALIZATION_FAILED"></a>
 ### ERR_ZLIB_INITIALIZATION_FAILED
 
diff --git a/doc/api/process.md b/doc/api/process.md
index 28ed9734f55144..0ba97f851cce9f 100644
--- a/doc/api/process.md
+++ b/doc/api/process.md
@@ -2007,7 +2007,8 @@ console.log(
 );
 ```
 
-This feature is not available in [`Worker`][] threads.
+[`Worker`][] threads are able to read the umask, however attempting to set the
+umask will result in a thrown exception.
 
 ## process.uptime()
 <!-- YAML
diff --git a/lib/internal/bootstrap/node.js b/lib/internal/bootstrap/node.js
index 21f642e4d1d53a..2112cb9ee17fe6 100644
--- a/lib/internal/bootstrap/node.js
+++ b/lib/internal/bootstrap/node.js
@@ -82,6 +82,10 @@ function startup() {
     process._startProfilerIdleNotifier =
       rawMethods._startProfilerIdleNotifier;
     process._stopProfilerIdleNotifier = rawMethods._stopProfilerIdleNotifier;
+  } else {
+    const wrapped = workerThreadSetup.wrapProcessMethods(rawMethods);
+
+    process.umask = wrapped.umask;
   }
 
   // Set up methods on the process object for all threads
diff --git a/lib/internal/errors.js b/lib/internal/errors.js
index 45701c82523981..12b01ffb9b64f3 100644
--- a/lib/internal/errors.js
+++ b/lib/internal/errors.js
@@ -1001,4 +1001,6 @@ E('ERR_WORKER_UNSERIALIZABLE_ERROR',
 E('ERR_WORKER_UNSUPPORTED_EXTENSION',
   'The worker script extension must be ".js" or ".mjs". Received "%s"',
   TypeError);
+E('ERR_WORKER_UNSUPPORTED_OPERATION',
+  '%s is not supported in workers', TypeError);
 E('ERR_ZLIB_INITIALIZATION_FAILED', 'Initialization failed', Error);
diff --git a/lib/internal/process/worker_thread_only.js b/lib/internal/process/worker_thread_only.js
index 3fcd052542d09d..b29bc7a390d0e3 100644
--- a/lib/internal/process/worker_thread_only.js
+++ b/lib/internal/process/worker_thread_only.js
@@ -15,6 +15,10 @@ const {
   WritableWorkerStdio
 } = require('internal/worker/io');
 
+const {
+  codes: { ERR_WORKER_UNSUPPORTED_OPERATION }
+} = require('internal/errors');
+
 let debuglog;
 function debug(...args) {
   if (!debuglog) {
@@ -118,8 +122,23 @@ function createWorkerFatalExeception(port) {
   };
 }
 
+// The execution of this function itself should not cause any side effects.
+function wrapProcessMethods(binding) {
+  function umask(mask) {
+    // process.umask() is a read-only operation in workers.
+    if (mask !== undefined) {
+      throw new ERR_WORKER_UNSUPPORTED_OPERATION('Setting process.umask()');
+    }
+
+    return binding.umask(mask);
+  }
+
+  return { umask };
+}
+
 module.exports = {
   initializeWorkerStdio,
   createMessageHandler,
-  createWorkerFatalExeception
+  createWorkerFatalExeception,
+  wrapProcessMethods
 };
diff --git a/src/node_process_methods.cc b/src/node_process_methods.cc
index c9abe19b7e0b68..51758f05f6bc87 100644
--- a/src/node_process_methods.cc
+++ b/src/node_process_methods.cc
@@ -50,6 +50,10 @@ using v8::Uint32;
 using v8::Uint32Array;
 using v8::Value;
 
+namespace per_process {
+Mutex umask_mutex;
+}   // namespace per_process
+
 // Microseconds in a second, as a float, used in CPUUsage() below
 #define MICROS_PER_SEC 1e6
 // used in Hrtime() below
@@ -220,6 +224,7 @@ static void Umask(const FunctionCallbackInfo<Value>& args) {
 
   CHECK_EQ(args.Length(), 1);
   CHECK(args[0]->IsUndefined() || args[0]->IsUint32());
+  Mutex::ScopedLock scoped_lock(per_process::umask_mutex);
 
   if (args[0]->IsUndefined()) {
     old = umask(0);
@@ -396,9 +401,9 @@ static void InitializeProcessMethods(Local<Object> target,
         target, "_stopProfilerIdleNotifier", StopProfilerIdleNotifier);
     env->SetMethod(target, "abort", Abort);
     env->SetMethod(target, "chdir", Chdir);
-    env->SetMethod(target, "umask", Umask);
   }
 
+  env->SetMethod(target, "umask", Umask);
   env->SetMethod(target, "_rawDebug", RawDebug);
   env->SetMethod(target, "memoryUsage", MemoryUsage);
   env->SetMethod(target, "cpuUsage", CPUUsage);
diff --git a/test/common/index.js b/test/common/index.js
index c1fb28121e13c3..72ad0c3b77f41e 100644
--- a/test/common/index.js
+++ b/test/common/index.js
@@ -33,21 +33,20 @@ const {
   bits,
   hasIntl
 } = process.binding('config');
+const { isMainThread } = require('worker_threads');
 
 // Some tests assume a umask of 0o022 so set that up front. Tests that need a
 // different umask will set it themselves.
 //
-// process.umask() is not available in workers so we need to check for its
-// existence.
-if (process.umask)
+// Workers can read, but not set the umask, so check that this is the main
+// thread.
+if (isMainThread)
   process.umask(0o022);
 
 const noop = () => {};
 
 const hasCrypto = Boolean(process.versions.openssl);
 
-const { isMainThread } = require('worker_threads');
-
 // Check for flags. Skip this for workers (both, the `cluster` module and
 // `worker_threads`) and child processes.
 if (process.argv.length === 2 &&
diff --git a/test/parallel/test-fs-write-file-sync.js b/test/parallel/test-fs-write-file-sync.js
index 743a3858546931..013322ed15ba46 100644
--- a/test/parallel/test-fs-write-file-sync.js
+++ b/test/parallel/test-fs-write-file-sync.js
@@ -23,7 +23,7 @@
 const common = require('../common');
 
 if (!common.isMainThread)
-  common.skip('process.umask is not available in Workers');
+  common.skip('Setting process.umask is not supported in Workers');
 
 const assert = require('assert');
 const path = require('path');
diff --git a/test/parallel/test-process-umask-mask.js b/test/parallel/test-process-umask-mask.js
index 26ea5b1d9d21de..d599379761fd40 100644
--- a/test/parallel/test-process-umask-mask.js
+++ b/test/parallel/test-process-umask-mask.js
@@ -7,7 +7,7 @@ const common = require('../common');
 const assert = require('assert');
 
 if (!common.isMainThread)
-  common.skip('process.umask is not available in Workers');
+  common.skip('Setting process.umask is not supported in Workers');
 
 let mask;
 
diff --git a/test/parallel/test-process-umask.js b/test/parallel/test-process-umask.js
index b1e0c08bcbd352..592463eca17a9d 100644
--- a/test/parallel/test-process-umask.js
+++ b/test/parallel/test-process-umask.js
@@ -22,8 +22,15 @@
 'use strict';
 const common = require('../common');
 const assert = require('assert');
-if (!common.isMainThread)
-  common.skip('process.umask is not available in Workers');
+
+if (!common.isMainThread) {
+  assert.strictEqual(typeof process.umask(), 'number');
+  assert.throws(() => {
+    process.umask('0664');
+  }, { code: 'ERR_WORKER_UNSUPPORTED_OPERATION' });
+
+  common.skip('Setting process.umask is not supported in Workers');
+}
 
 // Note in Windows one can only set the "user" bits.
 let mask;