Expose the `recurring` flag on the async stack tagging API

This CL exposes the `recurring` flag on the experimental async stack
tagging API which was implemeted in the following CL:
https://chromium-review.googlesource.com/c/v8/v8/+/3212506

It serves as a prototype to check if such an API is suitable for
improving stack traces for frameworks which split up tasks across
multiple frames, yielding back to the main thread when some time budget
is consumed.

The tests are implemented as Blink web tests in the following CL:
https://chromium-review.googlesource.com/c/chromium/src/+/3383386

Bug: chromium:332624
Change-Id: I3e8c5de723cb7c0413d03ca4292c22d6a6e565b0
Signed-off-by: Victor Porof <victorporof@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3380495Reviewed-by: Simon Zünd <szuend@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78647}

src/inspector/v8-console.cc

@@ -513,7 +513,11 @@ v8::Maybe<int64_t> V8Console::ValidateAndGetTaskId(
 
 void V8Console::scheduleAsyncTask(
     const v8::FunctionCallbackInfo<v8::Value>& info) {
-  if (info.Length() != 1) {
+  if (info.Length() != 1 && info.Length() != 2) {
+    info.GetIsolate()->ThrowError("Unexpected arguments");
+    return;
+  }
+  if (info.Length() == 2 && !info[1]->IsBoolean()) {
     info.GetIsolate()->ThrowError("Unexpected arguments");
     return;
   }
@@ -521,6 +525,8 @@ void V8Console::scheduleAsyncTask(
   v8::debug::ConsoleCallArguments args(info);
   ConsoleHelper helper(args, v8::debug::ConsoleContext(), m_inspector);
   String16 argName = helper.firstArgToString(String16());
+  bool recurring =
+      info.Length() == 2 ? info[1].As<v8::Boolean>()->Value() : false;
 
   int64_t id = m_taskIdCounter++;
   auto it = m_asyncTaskIds.find(id);
@@ -529,11 +535,13 @@ void V8Console::scheduleAsyncTask(
     return;
   }
 
-  int* taskPtr = new int();
-  m_asyncTaskIds.emplace(id, taskPtr);
+  AsyncTaskInfo taskInfo;
+  taskInfo.ptr = new int();
+  taskInfo.recurring = recurring;
+  m_asyncTaskIds.emplace(id, taskInfo);
 
   StringView taskName = StringView(argName.characters16(), argName.length());
-  m_inspector->asyncTaskScheduled(taskName, taskPtr, false);
+  m_inspector->asyncTaskScheduled(taskName, taskInfo.ptr, recurring);
 
   info.GetReturnValue().Set(v8::Number::New(info.GetIsolate(), id));
 }
@@ -544,8 +552,8 @@ void V8Console::startAsyncTask(
   if (maybeArgId.IsNothing()) return;
 
   int64_t taskId = maybeArgId.FromJust();
-  int* taskPtr = m_asyncTaskIds[taskId];
-  m_inspector->asyncTaskStarted(taskPtr);
+  AsyncTaskInfo taskInfo = m_asyncTaskIds[taskId];
+  m_inspector->asyncTaskStarted(taskInfo.ptr);
 }
 
 void V8Console::finishAsyncTask(
@@ -554,10 +562,14 @@ void V8Console::finishAsyncTask(
   if (maybeArgId.IsNothing()) return;
 
   int64_t taskId = maybeArgId.FromJust();
-  int* taskPtr = m_asyncTaskIds[taskId];
-  m_inspector->asyncTaskFinished(taskPtr);
+  AsyncTaskInfo taskInfo = m_asyncTaskIds[taskId];
+  m_inspector->asyncTaskFinished(taskInfo.ptr);
+
+  if (taskInfo.recurring) {
+    return;
+  }
 
-  delete taskPtr;
+  delete taskInfo.ptr;
   m_asyncTaskIds.erase(taskId);
 }
 
@@ -567,10 +579,10 @@ void V8Console::cancelAsyncTask(
   if (maybeArgId.IsNothing()) return;
 
   int64_t taskId = maybeArgId.FromJust();
-  int* taskPtr = m_asyncTaskIds[taskId];
-  m_inspector->asyncTaskCanceled(taskPtr);
+  AsyncTaskInfo taskInfo = m_asyncTaskIds[taskId];
+  m_inspector->asyncTaskCanceled(taskInfo.ptr);
 
-  delete taskPtr;
+  delete taskInfo.ptr;
   m_asyncTaskIds.erase(taskId);
 }
 

src/inspector/v8-console.h

@@ -56,6 +56,11 @@ class V8Console : public v8::debug::ConsoleDelegate {
     v8::Local<v8::ArrayBuffer> m_thisReference;
   };
 
+  struct AsyncTaskInfo {
+    int* ptr;
+    bool recurring;
+  };
+
   explicit V8Console(V8InspectorImpl* inspector);
 
  private:
@@ -185,11 +190,11 @@ class V8Console : public v8::debug::ConsoleDelegate {
 
   // A map of unique pointers used for the scheduling and joining async stacks.
   // The async stack traces instrumentation is exposed on the console object,
-  // behind a --experimental-async-stack-tagging-api flag. For now, it serves as
-  // a prototype that aims to validate whether the debugging experience can be
-  // improved for userland code that uses custom schedulers.
+  // behind a --experimental-async-stack-tagging-api flag. For now, it serves
+  // as a prototype that aims to validate whether the debugging experience can
+  // be improved for userland code that uses custom schedulers.
   int64_t m_taskIdCounter = 0;
-  std::map<int64_t, int*> m_asyncTaskIds;
+  std::map<int64_t, AsyncTaskInfo> m_asyncTaskIds;
 };
 
 }  // namespace v8_inspector