[inspector] introduced debug::SetAsyncTaskListener

src/debug/debug.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/debug/debug.h"
 
 #include <memory>
 
 #include "src/api.h"
 #include "src/arguments.h"
@@ skipping 1841 matching lines @@
   // Since we holding promise when at least one microtask is scheduled (inside
   // PromiseReactionJobInfo), we can send cancel event in weak callback.
   GlobalHandles::MakeWeak(
       global_handle.location(),
       new CollectedCallbackData(global_handle.location(), async_id->value(),
                                 this, isolate_),
       &ResetPromiseHandle, v8::WeakCallbackType::kParameter);
   return async_id->value();
 }
 
+void Debug::SetAsyncTaskListener(debug::AsyncTaskListener listener,
+                                 void* data) {
+  async_task_listener_ = listener;
+  async_task_listener_data_ = data;
+  UpdateState();
+}
+
 void Debug::OnAsyncTaskEvent(debug::PromiseDebugActionType type, int id) {
   if (in_debug_scope() || ignore_events()) return;
 
+  if (async_task_listener_) {
+    async_task_listener_(type, id, async_task_listener_data_);
+    // There are three types of event listeners: C++ message_handler,
+    // JavaScript event listener and C++ event listener.
+    // Currently inspector still uses C++ event listener and installs
+    // more specific event listeners for part of events. Calling of
+    // C++ event listener is redundant when more specific event listener
+    // is presented. Other clients can install JavaScript event listener
+    // (e.g. some of NodeJS module).
+    bool non_inspector_listener_exists =
+        message_handler_ != nullptr ||
+        (event_listener_.is_null() && !event_listener_->IsForeign());
+    if (!non_inspector_listener_exists) return;
+  }
+
   HandleScope scope(isolate_);
   DebugScope debug_scope(this);
   if (debug_scope.failed()) return;
 
   // Create the script collected state object.
   Handle<Object> event_data;
   // Bail out and don't call debugger if exception.
   if (!MakeAsyncTaskEvent(handle(Smi::FromInt(type), isolate_),
                           handle(Smi::FromInt(id), isolate_))
            .ToHandle(&event_data))
@@ skipping 262 matching lines @@
   message_handler_ = handler;
   UpdateState();
   if (handler == NULL && in_debug_scope()) {
     // Send an empty command to the debugger if in a break to make JavaScript
     // run again if the debugger is closed.
     EnqueueCommandMessage(Vector<const uint16_t>::empty());
   }
 }
 
 void Debug::UpdateState() {
-  bool is_active = message_handler_ != NULL || !event_listener_.is_null();
+  bool is_active = message_handler_ != nullptr || !event_listener_.is_null() ||
+                   async_task_listener_ != nullptr;
   if (is_active || in_debug_scope()) {
     // Note that the debug context could have already been loaded to
     // bootstrap test cases.
     isolate_->compilation_cache()->Disable();
     is_active = Load();
   } else if (is_loaded()) {
     isolate_->compilation_cache()->Enable();
     Unload();
   }
   is_active_ = is_active;
@@ skipping 467 matching lines @@
   logger_->DebugEvent("Put", message.text());
 }
 
 void LockingCommandMessageQueue::Clear() {
   base::LockGuard<base::Mutex> lock_guard(&mutex_);
   queue_.Clear();
 }
 
 }  // namespace internal
 }  // namespace v8