lib: replace global SharedArrayBuffer constructor with bound method

Renegade334 · aduh95 · commit 33baaf42c833 · 2025-11-13T22:44:17.000+01:00
PR-URL: #60497 Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com> Reviewed-By: Shelley Vohr <shelley.vohr@gmail.com> Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
diff --git a/lib/internal/main/worker_thread.js b/lib/internal/main/worker_thread.js
@@ -11,9 +11,6 @@ const{
 ObjectDefineProperty,
 PromisePrototypeThen,
 RegExpPrototypeExec,
- globalThis:{
- SharedArrayBuffer,
- },
 } = primordials;
 
 const{
@@ -119,23 +116,21 @@ port.on('message', (message) =>{
 require('internal/worker').assignEnvironmentData(environmentData);
 setupMainThreadPort(mainThreadPort);
 
- if (SharedArrayBuffer !== undefined){
- // The counter is only passed to the workers created by the main thread,
- // not to workers created by other workers.
- let cachedCwd = '';
- let lastCounter = -1;
- const originalCwd = process.cwd;
-
- process.cwd = function(){
- const currentCounter = AtomicsLoad(cwdCounter, 0);
- if (currentCounter === lastCounter)
- return cachedCwd;
- lastCounter = currentCounter;
- cachedCwd = originalCwd();
+ // The counter is only passed to the workers created by the main thread,
+ // not to workers created by other workers.
+ let cachedCwd = '';
+ let lastCounter = -1;
+ const originalCwd = process.cwd;
+
+ process.cwd = function(){
+ const currentCounter = AtomicsLoad(cwdCounter, 0);
+ if (currentCounter === lastCounter)
 return cachedCwd;
- };
- workerIo.sharedCwdCounter = cwdCounter;
- }
+ lastCounter = currentCounter;
+ cachedCwd = originalCwd();
+ return cachedCwd;
+ };
+ workerIo.sharedCwdCounter = cwdCounter;
 
 const isLoaderHookWorker = (filename === 'internal/modules/esm/worker' && doEval === 'internal');
 if (!isLoaderHookWorker){
diff --git a/lib/internal/modules/esm/hooks.js b/lib/internal/modules/esm/hooks.js
@@ -15,13 +15,8 @@ const{
 SafeSet,
 StringPrototypeSlice,
 StringPrototypeToUpperCase,
- globalThis,
 } = primordials;
 
-const{
- SharedArrayBuffer,
-} = globalThis;
-
 const{
 ERR_ASYNC_LOADER_REQUEST_NEVER_SETTLED,
 ERR_INTERNAL_ASSERTION,
@@ -44,6 +39,7 @@ const{
 validateString,
 } = require('internal/validators');
 const{
+ constructSharedArrayBuffer,
 kEmptyObject,
 } = require('internal/util');
 
@@ -535,7 +531,7 @@ class AsyncLoaderHookWorker{
 const{InternalWorker } = require('internal/worker');
 MessageChannel ??= require('internal/worker/io').MessageChannel;
 
- const lock = new SharedArrayBuffer(SHARED_MEMORY_BYTE_LENGTH);
+ const lock = constructSharedArrayBuffer(SHARED_MEMORY_BYTE_LENGTH);
 this.#lock = new Int32Array(lock);
 
 this.#worker = new InternalWorker('internal/modules/esm/worker',{
diff --git a/lib/internal/streams/fast-utf8-stream.js b/lib/internal/streams/fast-utf8-stream.js
@@ -9,13 +9,14 @@ const{
 AtomicsWait,
 Int32Array,
 MathMax,
+ Number,
 SymbolDispose,
- globalThis:{
- Number,
- SharedArrayBuffer,
- },
 } = primordials;
 
+const{
+ constructSharedArrayBuffer,
+} = require('internal/util');
+
 const{
 Buffer,
 } = require('buffer');
@@ -49,7 +50,7 @@ const{
 const BUSY_WRITE_TIMEOUT = 100;
 const kEmptyBuffer = Buffer.allocUnsafe(0);
 
-const kNil = new Int32Array(new SharedArrayBuffer(4));
+const kNil = new Int32Array(constructSharedArrayBuffer(4));
 
 function sleep(ms){
 // Also filters out NaN, non-number types, including empty strings, but allows bigints
diff --git a/lib/internal/worker.js b/lib/internal/worker.js
@@ -23,7 +23,6 @@ const{
 SymbolFor,
 TypedArrayPrototypeFill,
 Uint32Array,
- globalThis:{SharedArrayBuffer },
 } = primordials;
 
 const EventEmitter = require('events');
@@ -61,7 +60,10 @@ const{
 const{createMainThreadPort, destroyMainThreadPort } = require('internal/worker/messaging');
 const{deserializeError } = require('internal/error_serdes');
 const{fileURLToPath, isURL, pathToFileURL } = require('internal/url');
-const{kEmptyObject } = require('internal/util');
+const{
+ constructSharedArrayBuffer,
+ kEmptyObject,
+} = require('internal/util');
 const{validateArray, validateString, validateObject, validateNumber } = require('internal/validators');
 const{
 throwIfBuildingSnapshot,
@@ -105,9 +107,8 @@ let cwdCounter;
 
 const environmentData = new SafeMap();
 
-// SharedArrayBuffers can be disabled with --enable-sharedarraybuffer-per-context.
-if (isMainThread && SharedArrayBuffer !== undefined){
- cwdCounter = new Uint32Array(new SharedArrayBuffer(4));
+if (isMainThread){
+ cwdCounter = new Uint32Array(constructSharedArrayBuffer(4));
 const originalChdir = process.chdir;
 process.chdir = function(path){
 AtomicsAdd(cwdCounter, 0, 1);
diff --git a/lib/internal/worker/messaging.js b/lib/internal/worker/messaging.js
@@ -6,18 +6,17 @@ const{
 AtomicsWaitAsync,
 Int32Array,
 SafeMap,
- globalThis,
 } = primordials;
 
-const{
- SharedArrayBuffer,
-} = globalThis;
-
 const{
 isMainThread,
 threadId: currentThreadId,
 } = internalBinding('worker');
 
+const{
+ constructSharedArrayBuffer,
+} = require('internal/util');
+
 const{
 codes:{
 ERR_WORKER_MESSAGING_ERRORED,
@@ -203,7 +202,7 @@ async function postMessageToThread(threadId, value, transferList, timeout){
 throw new ERR_WORKER_MESSAGING_SAME_THREAD();
 }
 
- const memory = new SharedArrayBuffer(WORKER_MESSAGING_SHARED_DATA);
+ const memory = constructSharedArrayBuffer(WORKER_MESSAGING_SHARED_DATA);
 const status = new Int32Array(memory);
 const promise = AtomicsWaitAsync(status, WORKER_MESSAGING_STATUS_INDEX, 0, timeout).value;
 

-Original file line number
+Diff line change
  ObjectDefineProperty,
  PromisePrototypeThen,
  RegExpPrototypeExec,
 -globalThis: {
 - SharedArrayBuffer,
 -},
 }=primordials;
 const{
 require('internal/worker').assignEnvironmentData(environmentData);
 setupMainThreadPort(mainThreadPort);
 -if(SharedArrayBuffer!==undefined){
 -// The counter is only passed to the workers created by the main thread,
 -// not to workers created by other workers.
 -letcachedCwd='';
 -letlastCounter=-1;
 -constoriginalCwd=process.cwd;
+-
 -process.cwd=function(){
 -constcurrentCounter=AtomicsLoad(cwdCounter,0);
 -if(currentCounter===lastCounter)
 -returncachedCwd;
 -lastCounter=currentCounter;
 -cachedCwd=originalCwd();
 +// The counter is only passed to the workers created by the main thread,
 +// not to workers created by other workers.
 +letcachedCwd='';
 +letlastCounter=-1;
 +constoriginalCwd=process.cwd;
++
 +process.cwd=function(){
 +constcurrentCounter=AtomicsLoad(cwdCounter,0);
 +if(currentCounter===lastCounter)
 returncachedCwd;
 -};
 -workerIo.sharedCwdCounter=cwdCounter;
 -}
 +lastCounter=currentCounter;
 +cachedCwd=originalCwd();
 +returncachedCwd;
 +};
 +workerIo.sharedCwdCounter=cwdCounter;
 constisLoaderHookWorker=(filename==='internal/modules/esm/worker'&&doEval==='internal');
 if(!isLoaderHookWorker){
-Original file line number
+Diff line change
  SymbolFor,
  TypedArrayPrototypeFill,
  Uint32Array,
 -globalThis: { SharedArrayBuffer },
 }=primordials;
 constEventEmitter=require('events');
 const{ createMainThreadPort, destroyMainThreadPort }=require('internal/worker/messaging');
 const{ deserializeError }=require('internal/error_serdes');
 const{ fileURLToPath, isURL, pathToFileURL }=require('internal/url');
 -const{ kEmptyObject }=require('internal/util');
 +const{
 + constructSharedArrayBuffer,
 + kEmptyObject,
 +}=require('internal/util');
 const{ validateArray, validateString, validateObject, validateNumber }=require('internal/validators');
 const{
  throwIfBuildingSnapshot,
 constenvironmentData=newSafeMap();
 -// SharedArrayBuffers can be disabled with --enable-sharedarraybuffer-per-context.
 -if(isMainThread&&SharedArrayBuffer!==undefined){
 -cwdCounter=newUint32Array(newSharedArrayBuffer(4));
 +if(isMainThread){
 +cwdCounter=newUint32Array(constructSharedArrayBuffer(4));
 constoriginalChdir=process.chdir;
 process.chdir=function(path){
 AtomicsAdd(cwdCounter,0,1);