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.

PR-URL: https://github.com/nodejs/node/pull/26062
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

1 files changed, 32 insertions, 1 deletions

diff --git a/lib/internal/bootstrap/pre_execution.js b/lib/internal/bootstrap/pre_execution.js
index ce4af115ba..8c9d7e1eaf 100644
--- 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
 };