bootstrap: optimize modules loaded in the built-in snapshot

Preload essential modules and lazy-load non-essential ones. After this patch, all modules listed by running this snippet: ``` const list = process.moduleLoadList.join('\n'); require('fs').writeSync(1, list, 'utf-8'); ``` (which is roughly the same list as the one in test-bootstrap-module.js for the main thread) are loaded from the snapshot so no additional compilation cost is incurred. PR-URL: #45849 Reviewed-By: Geoffrey Booth <[email protected]> Reviewed-By: Chengzhong Wu <[email protected]>
nodejs · Jan 31, 2023 · b5fb3fb · b5fb3fb
1 parent b1a1798
commit b5fb3fb
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Showing 3 changed files with 38 additions and 12 deletions.
diff --git a/lib/internal/bootstrap/switches/is_main_thread.js b/lib/internal/bootstrap/switches/is_main_thread.js
@@ -286,3 +286,32 @@ rawMethods.resetStdioForTesting = function() {
   stdout = undefined;
   stderr = undefined;
 };
+
+// Needed by the module loader and generally needed everywhere.
+require('fs');
+require('util');
+require('url');
+
+require('internal/modules/cjs/loader');
+require('internal/modules/esm/utils');
+require('internal/vm/module');
+// Needed to refresh the time origin.
+require('internal/perf/utils');
+// Needed to register the async hooks.
+if (internalBinding('config').hasInspector) {
+  require('internal/inspector_async_hook');
+}
+// Needed to set the wasm web API callbacks.
+internalBinding('wasm_web_api');
+// Needed to detect whether it's on main thread.
+internalBinding('worker');
+// Needed to setup source maps.
+require('internal/source_map/source_map_cache');
+// Needed by most execution modes.
+require('internal/modules/run_main');
+// Needed to refresh DNS configurations.
+require('internal/dns/utils');
+// Needed by almost all execution modes. It's fine to
+// load them into the snapshot as long as we don't run
+// any of the initialization.
+require('internal/process/pre_execution');
diff --git a/lib/internal/process/pre_execution.js b/lib/internal/process/pre_execution.js
@@ -11,7 +11,6 @@ const {
 
 const {
   getOptionValue,
-  getEmbedderOptions,
   refreshOptions,
 } = require('internal/options');
 const { reconnectZeroFillToggle } = require('internal/buffer');
@@ -79,6 +78,7 @@ function prepareExecution(options) {
   initializeSourceMapsHandlers();
   initializeDeprecations();
   initializeWASI();
+
   require('internal/dns/utils').initializeDns();
 
   if (isMainThread) {
@@ -261,8 +261,9 @@ function setupFetch() {
   });
 
   // The WebAssembly Web API: https://webassembly.github.io/spec/web-api
-  const { wasmStreamingCallback } = require('internal/wasm_web_api');
-  internalBinding('wasm_web_api').setImplementation(wasmStreamingCallback);
+  internalBinding('wasm_web_api').setImplementation((streamState, source) => {
+    require('internal/wasm_web_api').wasmStreamingCallback(streamState, source);
+  });
 }
 
 // TODO(aduh95): move this to internal/bootstrap/browser when the CLI flag is
@@ -327,12 +328,12 @@ function setupStacktracePrinterOnSigint() {
 }
 
 function initializeReport() {
-  const { report } = require('internal/process/report');
   ObjectDefineProperty(process, 'report', {
     __proto__: null,
     enumerable: true,
     configurable: true,
     get() {
+      const { report } = require('internal/process/report');
       return report;
     }
   });
@@ -347,9 +348,10 @@ function setupDebugEnv() {
 
 // This has to be called after initializeReport() is called
 function initializeReportSignalHandlers() {
-  const { addSignalHandler } = require('internal/process/report');
-
-  addSignalHandler();
+  if (getOptionValue('--report-on-signal')) {
+    const { addSignalHandler } = require('internal/process/report');
+    addSignalHandler();
+  }
 }
 
 function initializeHeapSnapshotSignalHandlers() {
@@ -555,8 +557,6 @@ function initializeCJSLoader() {
 }
 
 function initializeESMLoader() {
-  if (getEmbedderOptions().shouldNotRegisterESMLoader) return;
-
   const { initializeESM } = require('internal/modules/esm/utils');
   initializeESM();
 

diff --git a/test/parallel/test-bootstrap-modules.js b/test/parallel/test-bootstrap-modules.js
@@ -24,7 +24,6 @@ const expectedModules = new Set([
   'Internal Binding options',
   'Internal Binding performance',
   'Internal Binding process_methods',
-  'Internal Binding report',
   'Internal Binding string_decoder',
   'Internal Binding symbols',
   'Internal Binding task_queue',
@@ -64,7 +63,6 @@ const expectedModules = new Set([
   'NativeModule internal/process/per_thread',
   'NativeModule internal/process/pre_execution',
   'NativeModule internal/process/promises',
-  'NativeModule internal/process/report',
   'NativeModule internal/process/signal',
   'NativeModule internal/process/task_queues',
   'NativeModule internal/process/warning',
@@ -79,7 +77,6 @@ const expectedModules = new Set([
   'NativeModule internal/validators',
   'NativeModule internal/vm',
   'NativeModule internal/vm/module',
-  'NativeModule internal/wasm_web_api',
   'NativeModule internal/worker/js_transferable',
   'Internal Binding blob',
   'NativeModule async_hooks',