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, 98 insertions, 0 deletions

diff --git a/src/inspector/worker_inspector.h b/src/inspector/worker_inspector.h
new file mode 100644
index 0000000000..e3c96cf62f
--- /dev/null
+++ b/src/inspector/worker_inspector.h
@@ -0,0 +1,98 @@
+#ifndef SRC_INSPECTOR_WORKER_INSPECTOR_H_
+#define SRC_INSPECTOR_WORKER_INSPECTOR_H_
+
+#if !HAVE_INSPECTOR
+#error("This header can only be used when inspector is enabled")
+#endif
+
+#include <memory>
+#include <string>
+#include <unordered_map>
+#include <unordered_set>
+
+namespace node {
+namespace inspector {
+class MainThreadHandle;
+class WorkerManager;
+
+class WorkerDelegate {
+ public:
+  virtual void WorkerCreated(const std::string& title,
+                             const std::string& url,
+                             bool waiting,
+                             std::shared_ptr<MainThreadHandle> worker) = 0;
+};
+
+class WorkerManagerEventHandle {
+ public:
+  explicit WorkerManagerEventHandle(std::shared_ptr<WorkerManager> manager,
+                                    int id)
+                                    : manager_(manager), id_(id) {}
+  void SetWaitOnStart(bool wait_on_start);
+  ~WorkerManagerEventHandle();
+
+ private:
+  std::shared_ptr<WorkerManager> manager_;
+  int id_;
+};
+
+struct WorkerInfo {
+  WorkerInfo(const std::string& target_title,
+             const std::string& target_url,
+             std::shared_ptr<MainThreadHandle> worker_thread)
+             : title(target_title),
+               url(target_url),
+               worker_thread(worker_thread) {}
+  std::string title;
+  std::string url;
+  std::shared_ptr<MainThreadHandle> worker_thread;
+};
+
+class ParentInspectorHandle {
+ public:
+  ParentInspectorHandle(int id, const std::string& url,
+                        std::shared_ptr<MainThreadHandle> parent_thread,
+                        bool wait_for_connect);
+  ~ParentInspectorHandle();
+  void WorkerStarted(std::shared_ptr<MainThreadHandle> worker_thread,
+                     bool waiting);
+  bool WaitForConnect() {
+    return wait_;
+  }
+
+ private:
+  int id_;
+  std::string url_;
+  std::shared_ptr<MainThreadHandle> parent_thread_;
+  bool wait_;
+};
+
+class WorkerManager : public std::enable_shared_from_this<WorkerManager> {
+ public:
+  explicit WorkerManager(std::shared_ptr<MainThreadHandle> thread)
+                         : thread_(thread) {}
+
+  std::unique_ptr<ParentInspectorHandle> NewParentHandle(
+      int thread_id, const std::string& url);
+  void WorkerStarted(int session_id, const WorkerInfo& info, bool waiting);
+  void WorkerFinished(int session_id);
+  std::unique_ptr<WorkerManagerEventHandle> SetAutoAttach(
+      std::unique_ptr<WorkerDelegate> attach_delegate);
+  void SetWaitOnStartForDelegate(int id, bool wait);
+  void RemoveAttachDelegate(int id);
+  std::shared_ptr<MainThreadHandle> MainThread() {
+    return thread_;
+  }
+
+ private:
+  std::shared_ptr<MainThreadHandle> thread_;
+  std::unordered_map<int, WorkerInfo> children_;
+  std::unordered_map<int, std::unique_ptr<WorkerDelegate>> delegates_;
+  // If any one needs it, workers stop for all
+  std::unordered_set<int> delegates_waiting_on_start_;
+  int next_delegate_id_ = 0;
+};
+}  // namespace inspector
+}  // namespace node
+
+#endif  // SRC_INSPECTOR_WORKER_INSPECTOR_H_