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.

Backport-PR-URL: #22954
PR-URL: #21364
Reviewed-By: Aleksei Koziatinskii <ak239spb@gmail.com>
Reviewed-By: Jan Krems <jan.krems@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

node.gyp

@@ -510,14 +510,18 @@
             'src/inspector_socket.cc',
             'src/inspector_socket_server.cc',
             'src/inspector/main_thread_interface.cc',
+            'src/inspector/worker_inspector.cc',
             'src/inspector/node_string.cc',
+            'src/inspector/worker_agent.cc',
             'src/inspector/tracing_agent.cc',
             'src/inspector_agent.h',
             'src/inspector_io.h',
             'src/inspector_socket.h',
             'src/inspector_socket_server.h',
             'src/inspector/main_thread_interface.h',
+            'src/inspector/worker_inspector.h',
             'src/inspector/node_string.h',
+            'src/inspector/worker_agent.h',
             'src/inspector/tracing_agent.h',
             '<@(node_inspector_generated_sources)'
           ],
@@ -1067,6 +1071,8 @@
           '<(SHARED_INTERMEDIATE_DIR)/src/node/inspector/protocol/Forward.h',
           '<(SHARED_INTERMEDIATE_DIR)/src/node/inspector/protocol/Protocol.cpp',
           '<(SHARED_INTERMEDIATE_DIR)/src/node/inspector/protocol/Protocol.h',
+          '<(SHARED_INTERMEDIATE_DIR)/src/node/inspector/protocol/NodeWorker.cpp',
+          '<(SHARED_INTERMEDIATE_DIR)/src/node/inspector/protocol/NodeWorker.h',
           '<(SHARED_INTERMEDIATE_DIR)/src/node/inspector/protocol/NodeTracing.cpp',
           '<(SHARED_INTERMEDIATE_DIR)/src/node/inspector/protocol/NodeTracing.h',
         ],

src/inspector/node_protocol.pdl

@@ -37,3 +37,58 @@ experimental domain NodeTracing
   # Signals that tracing is stopped and there is no trace buffers pending flush, all data were
   # delivered via dataCollected events.
   event tracingComplete
+
+# Support for sending messages to Node worker Inspector instances.
+experimental domain NodeWorker
+
+  type WorkerID extends string
+
+  # Unique identifier of attached debugging session.
+  type SessionID extends string
+
+  type WorkerInfo extends object
+    properties
+      WorkerID workerId
+      string type
+      string title
+      string url
+
+  # Sends protocol message over session with given id.
+  command sendMessageToWorker
+    parameters
+      string message
+      # Identifier of the session.
+      SessionID sessionId
+
+  # Instructs the inspector to attach to running workers. Will also attach to new workers
+  # as they start
+  command enable
+    parameters
+      # Whether to new workers should be paused until the frontend sends `Runtime.runIfWaitingForDebugger`
+      # message to run them.
+      boolean waitForDebuggerOnStart
+
+  # Detaches from all running workers and disables attaching to new workers as they are started.
+  command disable
+
+  # Issued when attached to a worker.
+  event attachedToWorker
+    parameters
+      # Identifier assigned to the session used to send/receive messages.
+      SessionID sessionId
+      WorkerInfo workerInfo
+      boolean waitingForDebugger
+
+  # Issued when detached from the worker.
+  event detachedFromWorker
+    parameters
+      # Detached session identifier.
+      SessionID sessionId
+
+  # Notifies about a new protocol message received from the session
+  # (session ID is provided in attachedToWorker notification).
+  event receivedMessageFromWorker
+    parameters
+      # Identifier of a session which sends a message.
+      SessionID sessionId
+      string message

src/inspector/node_protocol_config.json

@@ -3,12 +3,7 @@
         "path": "node_protocol.json",
         "package": "src/node/inspector/protocol",
         "output": "node/inspector/protocol",
-        "namespace": ["node", "inspector", "protocol"],
-        "options": [
-            {
-                "domain": "NodeTracing"
-            }
-        ]
+        "namespace": ["node", "inspector", "protocol"]
     },
     "exported": {
         "package": "include/inspector",

src/inspector/worker_agent.cc

@@ -0,0 +1,154 @@
+#include "worker_agent.h"
+
+#include "main_thread_interface.h"
+#include "worker_inspector.h"
+
+namespace node {
+namespace inspector {
+namespace protocol {
+
+class NodeWorkers
+    : public std::enable_shared_from_this<NodeWorkers> {
+ public:
+  explicit NodeWorkers(std::weak_ptr<NodeWorker::Frontend> frontend,
+                      std::shared_ptr<MainThreadHandle> thread)
+                      : frontend_(frontend), thread_(thread) {}
+  void WorkerCreated(const std::string& title,
+                     const std::string& url,
+                     bool waiting,
+                     std::shared_ptr<MainThreadHandle> target);
+  void Receive(const std::string& id, const std::string& message);
+  void Send(const std::string& id, const std::string& message);
+  void Detached(const std::string& id);
+
+ private:
+  std::weak_ptr<NodeWorker::Frontend> frontend_;
+  std::shared_ptr<MainThreadHandle> thread_;
+  std::unordered_map<std::string, std::unique_ptr<InspectorSession>> sessions_;
+  int next_target_id_ = 0;
+};
+
+namespace {
+class AgentWorkerInspectorDelegate : public WorkerDelegate {
+ public:
+  explicit AgentWorkerInspectorDelegate(std::shared_ptr<NodeWorkers> workers)
+                                        : workers_(workers) {}
+
+  void WorkerCreated(const std::string& title,
+                     const std::string& url,
+                     bool waiting,
+                     std::shared_ptr<MainThreadHandle> target) override {
+    workers_->WorkerCreated(title, url, waiting, target);
+  }
+
+ private:
+  std::shared_ptr<NodeWorkers> workers_;
+};
+
+class ParentInspectorSessionDelegate : public InspectorSessionDelegate {
+ public:
+  ParentInspectorSessionDelegate(const std::string& id,
+                                 std::shared_ptr<NodeWorkers> workers)
+                                 : id_(id), workers_(workers) {}
+
+  ~ParentInspectorSessionDelegate() override {
+    workers_->Detached(id_);
+  }
+
+  void SendMessageToFrontend(const v8_inspector::StringView& msg) override {
+    std::string message = protocol::StringUtil::StringViewToUtf8(msg);
+    workers_->Send(id_, message);
+  }
+
+ private:
+  std::string id_;
+  std::shared_ptr<NodeWorkers> workers_;
+};
+
+std::unique_ptr<NodeWorker::WorkerInfo> WorkerInfo(const std::string& id,
+                                                   const std::string& title,
+                                                   const std::string& url) {
+  return NodeWorker::WorkerInfo::create()
+      .setWorkerId(id)
+      .setTitle(title)
+      .setUrl(url)
+      .setType("worker").build();
+}
+}  // namespace
+
+WorkerAgent::WorkerAgent(std::weak_ptr<WorkerManager> manager)
+                         : manager_(manager) {}
+
+
+void WorkerAgent::Wire(UberDispatcher* dispatcher) {
+  frontend_.reset(new NodeWorker::Frontend(dispatcher->channel()));
+  NodeWorker::Dispatcher::wire(dispatcher, this);
+  auto manager = manager_.lock();
+  CHECK_NOT_NULL(manager);
+  workers_ =
+      std::make_shared<NodeWorkers>(frontend_, manager->MainThread());
+}
+
+DispatchResponse WorkerAgent::sendMessageToWorker(const String& message,
+                                                  const String& sessionId) {
+  workers_->Receive(sessionId, message);
+  return DispatchResponse::OK();
+}
+
+DispatchResponse WorkerAgent::enable(bool waitForDebuggerOnStart) {
+  auto manager = manager_.lock();
+  if (!manager) {
+    return DispatchResponse::OK();
+  }
+  if (!event_handle_) {
+    std::unique_ptr<AgentWorkerInspectorDelegate> delegate(
+            new AgentWorkerInspectorDelegate(workers_));
+    event_handle_ = manager->SetAutoAttach(std::move(delegate));
+  }
+  event_handle_->SetWaitOnStart(waitForDebuggerOnStart);
+  return DispatchResponse::OK();
+}
+
+DispatchResponse WorkerAgent::disable() {
+  event_handle_.reset();
+  return DispatchResponse::OK();
+}
+
+void NodeWorkers::WorkerCreated(const std::string& title,
+                                const std::string& url,
+                                bool waiting,
+                                std::shared_ptr<MainThreadHandle> target) {
+  auto frontend = frontend_.lock();
+  if (!frontend)
+    return;
+  std::string id = std::to_string(++next_target_id_);
+  auto delegate = thread_->MakeDelegateThreadSafe(
+      std::unique_ptr<InspectorSessionDelegate>(
+          new ParentInspectorSessionDelegate(id, shared_from_this())));
+  sessions_[id] = target->Connect(std::move(delegate), true);
+  frontend->attachedToWorker(id, WorkerInfo(id, title, url), waiting);
+}
+
+void NodeWorkers::Send(const std::string& id, const std::string& message) {
+  auto frontend = frontend_.lock();
+  if (frontend)
+    frontend->receivedMessageFromWorker(id, message);
+}
+
+void NodeWorkers::Receive(const std::string& id, const std::string& message) {
+  auto it = sessions_.find(id);
+  if (it != sessions_.end())
+    it->second->Dispatch(Utf8ToStringView(message)->string());
+}
+
+void NodeWorkers::Detached(const std::string& id) {
+  if (sessions_.erase(id) == 0)
+    return;
+  auto frontend = frontend_.lock();
+  if (frontend) {
+    frontend->detachedFromWorker(id);
+  }
+}
+}  // namespace protocol
+}  // namespace inspector
+}  // namespace node

src/inspector/worker_agent.h

@@ -0,0 +1,39 @@
+#ifndef SRC_INSPECTOR_WORKER_AGENT_H_
+#define SRC_INSPECTOR_WORKER_AGENT_H_
+
+#include "node/inspector/protocol/NodeWorker.h"
+#include "v8.h"
+
+
+namespace node {
+namespace inspector {
+class WorkerManagerEventHandle;
+class WorkerManager;
+
+namespace protocol {
+class NodeWorkers;
+
+class WorkerAgent : public NodeWorker::Backend {
+ public:
+  explicit WorkerAgent(std::weak_ptr<WorkerManager> manager);
+  ~WorkerAgent() override = default;
+
+  void Wire(UberDispatcher* dispatcher);
+
+  DispatchResponse sendMessageToWorker(const String& message,
+                                       const String& sessionId) override;
+
+  DispatchResponse enable(bool waitForDebuggerOnStart) override;
+  DispatchResponse disable() override;
+
+ private:
+  std::shared_ptr<NodeWorker::Frontend> frontend_;
+  std::weak_ptr<WorkerManager> manager_;
+  std::unique_ptr<WorkerManagerEventHandle> event_handle_;
+  std::shared_ptr<NodeWorkers> workers_;
+};
+}  // namespace protocol
+}  // namespace inspector
+}  // namespace node
+
+#endif  // SRC_INSPECTOR_WORKER_AGENT_H_