src: fix uninitialized field access in AsyncHooks

Co-authored-by: Joyee Cheung <[email protected]>
PR-URL: nodejs#48566
Reviewed-By: Ben Noordhuis <[email protected]>
Reviewed-By: Santiago Gimeno <[email protected]>
Reviewed-By: Luigi Pinca <[email protected]>
Reviewed-By: Joyee Cheung <[email protected]>
Reviewed-By: Minwoo Jung <[email protected]>
Reviewed-By: Gerhard Stöbich <[email protected]>

Author: 2 people

src/env.cc

@@ -170,15 +170,13 @@ bool AsyncHooks::pop_async_context(double async_id) {
 }
 
 void AsyncHooks::clear_async_id_stack() {
-  if (env()->can_call_into_js()) {
+  if (!js_execution_async_resources_.IsEmpty() && env()->can_call_into_js()) {
     Isolate* isolate = env()->isolate();
     HandleScope handle_scope(isolate);
-    if (!js_execution_async_resources_.IsEmpty()) {
-      USE(PersistentToLocal::Strong(js_execution_async_resources_)
-              ->Set(env()->context(),
-                    env()->length_string(),
-                    Integer::NewFromUnsigned(isolate, 0)));
-    }
+    USE(PersistentToLocal::Strong(js_execution_async_resources_)
+            ->Set(env()->context(),
+                  env()->length_string(),
+                  Integer::NewFromUnsigned(isolate, 0)));
   }
 
   native_execution_async_resources_.clear();

src/env.h

@@ -1015,6 +1015,10 @@ class Environment : public MemoryRetainer {
   uv_async_t task_queues_async_;
   int64_t task_queues_async_refs_ = 0;
 
+  // These may be read by ctors and should be listed before complex fields.
+  std::atomic_bool is_stopping_{false};
+  std::atomic_bool can_call_into_js_{true};
+
   AsyncHooks async_hooks_;
   ImmediateInfo immediate_info_;
   AliasedInt32Array timeout_info_;
@@ -1092,7 +1096,6 @@ class Environment : public MemoryRetainer {
 
   bool has_serialized_options_ = false;
 
-  std::atomic_bool can_call_into_js_ { true };
   uint64_t flags_;
   uint64_t thread_id_;
   std::unordered_set<worker::Worker*> sub_worker_contexts_;
@@ -1150,8 +1153,6 @@ class Environment : public MemoryRetainer {
   CleanupQueue cleanup_queue_;
   bool started_cleanup_ = false;
 
-  std::atomic_bool is_stopping_ { false };
-
   std::unordered_set<int> unmanaged_fds_;
 
   std::function<void(Environment*, ExitCode)> process_exit_handler_{