bootstrap: make I/O streams work with user-land snapshot

Use the mksnapshot cleanup hooks to release the references
to the native streams so that they can be destroyed right
before the snapshot is taken, and move the initialization
of the global console to pre-execution so that they can be
re-initialized during snapshot dehydration. This makes
it possible for user-land snapshots to use the I/O during
snapshot building.

PR-URL: #42466
Reviewed-By: Darshan Sen <[email protected]>
Reviewed-By: Mohammed Keyvanzadeh <[email protected]>
Reviewed-By: Khaidi Chu <[email protected]>
Reviewed-By: Chengzhong Wu <[email protected]>

Author: joyeecheung

lib/internal/bootstrap/pre_execution.js

@@ -121,6 +121,12 @@ function patchProcessObject(expandArgv1) {
     }
   }
 
+  // We need to initialize the global console here again with process.stdout
+  // and friends for snapshot deserialization.
+  const globalConsole = require('internal/console/global');
+  const { initializeGlobalConsole } = require('internal/console/constructor');
+  initializeGlobalConsole(globalConsole);
+
   // TODO(joyeecheung): most of these should be deprecated and removed,
   // except some that we need to be able to mutate during run time.
   addReadOnlyProcessAlias('_eval', '--eval');

lib/internal/bootstrap/switches/is_main_thread.js

@@ -122,27 +122,53 @@ 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);
+    stdout = undefined;
+  });
   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);
+    stderr = undefined;
+  });
   return stderr;
 }
 
@@ -229,6 +255,10 @@ function getStdin() {
     }
   }
 
+  internalBinding('mksnapshot').cleanups.push(function cleanupStdin() {
+    stdin.destroy();
+    stdin = undefined;
+  });
   return stdin;
 }
 

lib/internal/console/constructor.js

@@ -669,9 +669,15 @@ Console.prototype.dirxml = Console.prototype.log;
 Console.prototype.error = Console.prototype.warn;
 Console.prototype.groupCollapsed = Console.prototype.group;
 
+function initializeGlobalConsole(globalConsole) {
+  globalConsole[kBindStreamsLazy](process);
+  globalConsole[kBindProperties](true, 'auto');
+}
+
 module.exports = {
   Console,
   kBindStreamsLazy,
   kBindProperties,
+  initializeGlobalConsole,
   formatTime // exported for tests
 };

lib/internal/console/global.js

@@ -21,9 +21,7 @@ const {
 } = primordials;
 
 const {
-  Console,
-  kBindStreamsLazy,
-  kBindProperties
+  Console
 } = require('internal/console/constructor');
 
 const globalConsole = ObjectCreate({});
@@ -44,9 +42,6 @@ for (const prop of ReflectOwnKeys(Console.prototype)) {
   ReflectDefineProperty(globalConsole, prop, desc);
 }
 
-globalConsole[kBindStreamsLazy](process);
-globalConsole[kBindProperties](true, 'auto');
-
 // This is a legacy feature - the Console constructor is exposed on
 // the global console instance.
 globalConsole.Console = Console;