lib: cleanup stdio after snapshot building

Author: joyeecheung

lib/internal/bootstrap/pre_execution.js

@@ -20,7 +20,7 @@ const { Buffer } = require('buffer');
 const { ERR_MANIFEST_ASSERT_INTEGRITY } = require('internal/errors').codes;
 const assert = require('internal/assert');
 
-function prepareMainThreadExecution(expandArgv1 = false) {
+function prepareMainThreadExecution(expandArgv1 = false, initialzeModules = true) {
   refreshRuntimeOptions();
 
   // TODO(joyeecheung): this is also necessary for workers when they deserialize
@@ -73,6 +73,9 @@ function prepareMainThreadExecution(expandArgv1 = false) {
   initializeCJSLoader();
   initializeESMLoader();
 
+  if (!initialzeModules) {
+    return;
+  }
   const CJSLoader = require('internal/modules/cjs/loader');
   assert(!CJSLoader.hasLoadedAnyUserCJSModule);
   loadPreloadModules();

lib/internal/bootstrap/switches/is_main_thread.js

@@ -117,27 +117,51 @@ let stdin;
 let stdout;
 let stderr;
 
+let stdoutDestroy;
+let stderrDestroy;
+
+function refreshStdoutOnSigWinch() {
+  stdout._refreshSize();
+}
+
+function refreshStderrOnSigWinch() {
+  stderr._refreshSize();
+}
+
 function getStdout() {
   if (stdout) return stdout;
   stdout = createWritableStdioStream(1);
   stdout.destroySoon = stdout.destroy;
   // Override _destroy so that the fd is never actually closed.
+  stdoutDestroy = stdout._destroy;
   stdout._destroy = dummyDestroy;
   if (stdout.isTTY) {
-    process.on('SIGWINCH', () => stdout._refreshSize());
+    process.on('SIGWINCH', refreshStdoutOnSigWinch);
   }
+
+  internalBinding('mksnapshot').cleanups.push(function cleanupStdout() {
+    stdout._destroy = stdoutDestroy;
+    stdout.destroy();
+    process.removeListener('SIGWINCH', refreshStdoutOnSigWinch);
+  });
   return stdout;
 }
 
 function getStderr() {
   if (stderr) return stderr;
   stderr = createWritableStdioStream(2);
   stderr.destroySoon = stderr.destroy;
+  stderrDestroy = stderr._destroy;
   // Override _destroy so that the fd is never actually closed.
   stderr._destroy = dummyDestroy;
   if (stderr.isTTY) {
-    process.on('SIGWINCH', () => stderr._refreshSize());
+    process.on('SIGWINCH', refreshStderrOnSigWinch);
   }
+  internalBinding('mksnapshot').cleanups.push(function cleanupStderr() {
+    stderr._destroy = stderrDestroy;
+    stderr.destroy();
+    process.removeListener('SIGWINCH', refreshStderrOnSigWinch);
+  });
   return stderr;
 }
 
@@ -224,6 +248,9 @@ function getStdin() {
     }
   }
 
+  internalBinding('mksnapshot').cleanups.push(function cleanupStdin() {
+    stdin.destroy();
+  });
   return stdin;
 }
 

lib/internal/main/mksnapshot.js

@@ -5,9 +5,10 @@ const {
   SafeArrayIterator
 } = primordials;
 
+const binding = internalBinding('mksnapshot');
 const {
-  compileSnapshotMain
-} = internalBinding('mksnapshot');
+  compileSnapshotMain,
+} = binding;
 
 const {
   getOptionValue
@@ -101,7 +102,14 @@ function requireForUserSnapshot(id) {
   return require(id);
 }
 
-// prepareMainThreadExecution(true);
+require('internal/bootstrap/pre_execution').prepareMainThreadExecution(true, false);
+
+process.on('beforeExit', function() {
+  for (const cleanup of binding.cleanups) {
+    cleanup();
+  }
+  binding.cleanups = undefined;
+});
 
 const mainFile = readFileSync(getOptionValue('--snapshot-main'), 'utf-8');
 

src/node_snapshotable.cc

@@ -818,7 +818,13 @@ static void Initialize(Local<Object> target,
                        Local<Context> context,
                        void* priv) {
   Environment* env = Environment::GetCurrent(context);
+  Isolate* isolate = context->GetIsolate();
   env->SetMethod(target, "compileSnapshotMain", CompileSnapshotMain);
+  target
+      ->Set(context,
+            FIXED_ONE_BYTE_STRING(isolate, "cleanups"),
+            v8::Array::New(isolate))
+      .Check();
 }
 
 static void RegisterExternalReferences(ExternalReferenceRegistry* registry) {