inspector: workers debugging

Introduce a NodeTarget inspector domain modelled after ChromeDevTools
Target domain. It notifies inspector frontend attached to a main V8
isolate when workers are starting and allows passing messages to
inspectors on their isolates. All inspector functionality is enabled on
worker isolates.

PR-URL: https://github.com/nodejs/node/pull/21364
Reviewed-By: Aleksei Koziatinskii <ak239spb@gmail.com>
Reviewed-By: Jan Krems <jan.krems@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

1 files changed, 128 insertions, 0 deletions

diff --git a/src/inspector/worker_inspector.cc b/src/inspector/worker_inspector.cc
new file mode 100644
index 0000000000..52e71a562d
--- /dev/null
+++ b/src/inspector/worker_inspector.cc
@@ -0,0 +1,128 @@
+#include "worker_inspector.h"
+
+#include "main_thread_interface.h"
+
+namespace node {
+namespace inspector {
+namespace {
+
+class WorkerStartedRequest : public Request {
+ public:
+  WorkerStartedRequest(
+      int id,
+      const std::string& url,
+      std::shared_ptr<node::inspector::MainThreadHandle> worker_thread,
+      bool waiting)
+      : id_(id),
+        info_(BuildWorkerTitle(id), url, worker_thread),
+        waiting_(waiting) {}
+  void Call(MainThreadInterface* thread) override {
+    auto manager = thread->inspector_agent()->GetWorkerManager();
+    manager->WorkerStarted(id_, info_, waiting_);
+  }
+
+ private:
+  static std::string BuildWorkerTitle(int id) {
+    return "Worker " + std::to_string(id);
+  }
+
+  int id_;
+  WorkerInfo info_;
+  bool waiting_;
+};
+
+
+void Report(const std::unique_ptr<WorkerDelegate>& delegate,
+            const WorkerInfo& info, bool waiting) {
+  if (info.worker_thread)
+    delegate->WorkerCreated(info.title, info.url, waiting, info.worker_thread);
+}
+
+class WorkerFinishedRequest : public Request {
+ public:
+  explicit WorkerFinishedRequest(int worker_id) : worker_id_(worker_id) {}
+
+  void Call(MainThreadInterface* thread) override {
+    thread->inspector_agent()->GetWorkerManager()->WorkerFinished(worker_id_);
+  }
+
+ private:
+  int worker_id_;
+};
+}  // namespace
+
+
+ParentInspectorHandle::ParentInspectorHandle(
+    int id, const std::string& url,
+    std::shared_ptr<MainThreadHandle> parent_thread, bool wait_for_connect)
+    : id_(id), url_(url), parent_thread_(parent_thread),
+      wait_(wait_for_connect) {}
+
+ParentInspectorHandle::~ParentInspectorHandle() {
+  parent_thread_->Post(
+      std::unique_ptr<Request>(new WorkerFinishedRequest(id_)));
+}
+
+void ParentInspectorHandle::WorkerStarted(
+    std::shared_ptr<MainThreadHandle> worker_thread, bool waiting) {
+  std::unique_ptr<Request> request(
+      new WorkerStartedRequest(id_, url_, worker_thread, waiting));
+  parent_thread_->Post(std::move(request));
+}
+
+void WorkerManager::WorkerFinished(int session_id) {
+  children_.erase(session_id);
+}
+
+void WorkerManager::WorkerStarted(int session_id,
+                                  const WorkerInfo& info,
+                                  bool waiting) {
+  if (info.worker_thread->Expired())
+    return;
+  children_.emplace(session_id, info);
+  for (const auto& delegate : delegates_) {
+    Report(delegate.second, info, waiting);
+  }
+}
+
+std::unique_ptr<ParentInspectorHandle>
+WorkerManager::NewParentHandle(int thread_id, const std::string& url) {
+  bool wait = !delegates_waiting_on_start_.empty();
+  return std::unique_ptr<ParentInspectorHandle>(
+      new ParentInspectorHandle(thread_id, url, thread_, wait));
+}
+
+void WorkerManager::RemoveAttachDelegate(int id) {
+  delegates_.erase(id);
+  delegates_waiting_on_start_.erase(id);
+}
+
+std::unique_ptr<WorkerManagerEventHandle> WorkerManager::SetAutoAttach(
+    std::unique_ptr<WorkerDelegate> attach_delegate) {
+  int id = ++next_delegate_id_;
+  delegates_[id] = std::move(attach_delegate);
+  const auto& delegate = delegates_[id];
+  for (const auto& worker : children_) {
+    // Waiting is only reported when a worker is started, same as browser
+    Report(delegate, worker.second, false);
+  }
+  return std::unique_ptr<WorkerManagerEventHandle>(
+      new WorkerManagerEventHandle(shared_from_this(), id));
+}
+
+void WorkerManager::SetWaitOnStartForDelegate(int id, bool wait) {
+  if (wait)
+    delegates_waiting_on_start_.insert(id);
+  else
+    delegates_waiting_on_start_.erase(id);
+}
+
+void WorkerManagerEventHandle::SetWaitOnStart(bool wait_on_start) {
+    manager_->SetWaitOnStartForDelegate(id_, wait_on_start);
+}
+
+WorkerManagerEventHandle::~WorkerManagerEventHandle() {
+  manager_->RemoveAttachDelegate(id_);
+}
+}  // namespace inspector
+}  // namespace node