src: move async hooks trace events setup to pre_execution.js

Reasons: - Moves more environment-dependent setup out of bootstrap/node.js - No async operations should be done before the call to the setup functions in pre_execution.js so no async hooks should be triggered before that. Therefore it is safe to delay the setup until then.
nodejs · joyeecheung · Feb 10, 2019 · Feb 10, 2019 · Feb 19, 2019 · Feb 19, 2019
commit b5f6b6557d8c09dd17e6312d5605f94693b7443a
diff --git a/lib/internal/bootstrap/node.js b/lib/internal/bootstrap/node.js
@@ -42,8 +42,6 @@ const { getOptionValue } = NativeModule.require('internal/options');
 const config = internalBinding('config');
 const { deprecate } = NativeModule.require('internal/util');
 
-setupTraceCategoryState();
-
 setupProcessObject();
 
 setupGlobalProxy();
@@ -316,35 +314,6 @@ if (getOptionValue('--experimental-report')) {
   }
 }
 
-function setupTraceCategoryState() {
-  const {
-    traceCategoryState,
-    setTraceCategoryStateUpdateHandler
-  } = internalBinding('trace_events');
-  const kCategoryAsyncHooks = 0;
-  let traceEventsAsyncHook;
-
-  function toggleTraceCategoryState() {
-    // Dynamically enable/disable the traceEventsAsyncHook
-    const asyncHooksEnabled = !!traceCategoryState[kCategoryAsyncHooks];
-
-    if (asyncHooksEnabled) {
-      // Lazy load internal/trace_events_async_hooks only if the async_hooks
-      // trace event category is enabled.
-      if (!traceEventsAsyncHook) {
-        traceEventsAsyncHook =
-          NativeModule.require('internal/trace_events_async_hooks');
-      }
-      traceEventsAsyncHook.enable();
-    } else if (traceEventsAsyncHook) {
-      traceEventsAsyncHook.disable();
-    }
-  }
-
-  toggleTraceCategoryState();
-  setTraceCategoryStateUpdateHandler(toggleTraceCategoryState);
-}
-
 function setupProcessObject() {
   const EventEmitter = NativeModule.require('events');
   const origProcProto = Object.getPrototypeOf(process);

diff --git a/lib/internal/bootstrap/pre_execution.js b/lib/internal/bootstrap/pre_execution.js
@@ -3,6 +3,8 @@
 const { getOptionValue } = require('internal/options');
 
 function prepareMainThreadExecution() {
+  setupTraceCategoryState();
+
   // If the process is spawned with env NODE_CHANNEL_FD, it's probably
   // spawned by our child_process module, then initialize IPC.
   // This attaches some internal event listeners and creates:
@@ -23,6 +25,34 @@ function prepareMainThreadExecution() {
   loadPreloadModules();
 }
 
+function setupTraceCategoryState() {
+  const {
+    traceCategoryState,
+    setTraceCategoryStateUpdateHandler
+  } = internalBinding('trace_events');
+  const kCategoryAsyncHooks = 0;
+  let traceEventsAsyncHook;
+
+  function toggleTraceCategoryState() {
+    // Dynamically enable/disable the traceEventsAsyncHook
+    const asyncHooksEnabled = !!traceCategoryState[kCategoryAsyncHooks];
+
+    if (asyncHooksEnabled) {
+      // Lazy load internal/trace_events_async_hooks only if the async_hooks
+      // trace event category is enabled.
+      if (!traceEventsAsyncHook) {
+        traceEventsAsyncHook = require('internal/trace_events_async_hooks');
+      }
+      traceEventsAsyncHook.enable();
+    } else if (traceEventsAsyncHook) {
+      traceEventsAsyncHook.disable();
+    }
+  }
+
+  toggleTraceCategoryState();
+  setTraceCategoryStateUpdateHandler(toggleTraceCategoryState);
+}
+
 // In general deprecations are intialized wherever the APIs are implemented,
 // this is used to deprecate APIs implemented in C++ where the deprecation
 // utitlities are not easily accessible.
@@ -150,5 +180,6 @@ module.exports = {
   prepareMainThreadExecution,
   initializeDeprecations,
   initializeESMLoader,
-  loadPreloadModules
+  loadPreloadModules,
+  setupTraceCategoryState
 };
diff --git a/lib/internal/main/check_syntax.js b/lib/internal/main/check_syntax.js
@@ -22,14 +22,16 @@ if (process.argv[1] && process.argv[1] !== '-') {
   // Expand process.argv[1] into a full path.
   const path = require('path');
   process.argv[1] = path.resolve(process.argv[1]);
+
+  // TODO(joyeecheung): not every one of these are necessary
+  prepareMainThreadExecution();
+
   // Read the source.
   const filename = CJSModule._resolveFilename(process.argv[1]);
 
   const fs = require('fs');
   const source = fs.readFileSync(filename, 'utf-8');
 
-  // TODO(joyeecheung): not every one of these are necessary
-  prepareMainThreadExecution();
   markBootstrapComplete();
 
   checkScriptSyntax(source, filename);

diff --git a/lib/internal/main/worker_thread.js b/lib/internal/main/worker_thread.js
@@ -6,7 +6,8 @@
 const {
   initializeDeprecations,
   initializeESMLoader,
-  loadPreloadModules
+  loadPreloadModules,
+  setupTraceCategoryState
 } = require('internal/bootstrap/pre_execution');
 
 const {
@@ -72,6 +73,8 @@ port.on('message', (message) => {
       manifestURL,
       hasStdin
     } = message;
+
+    setupTraceCategoryState();
     if (manifestSrc) {
       require('internal/process/policy').setup(manifestSrc, manifestURL);
     }