[inspector] improved V8Debugger::breakProgram method

We should be ready for gone agent.

BUG=chromium:714819
R=dgozman@chromium.org

Review-Url: https://codereview.chromium.org/2842903002
Cr-Commit-Position: refs/heads/master@{#44874}

src/inspector/v8-debugger-agent-impl.cc

@@ -1250,7 +1250,7 @@ void V8DebuggerAgentImpl::breakProgram(
   std::vector<BreakReason> currentScheduledReason;
   currentScheduledReason.swap(m_breakReason);
   pushBreakDetails(breakReason, std::move(data));
-  m_debugger->breakProgram();
+  if (!m_debugger->breakProgram(m_session->contextGroupId())) return;
   popBreakDetails();
   m_breakReason.swap(currentScheduledReason);
   if (!m_breakReason.empty()) {

src/inspector/v8-debugger.cc

@@ -354,11 +354,14 @@ bool V8Debugger::canBreakProgram() {
   return !v8::debug::AllFramesOnStackAreBlackboxed(m_isolate);
 }
 
-void V8Debugger::breakProgram() {
+bool V8Debugger::breakProgram(int targetContextGroupId) {
   // Don't allow nested breaks.
-  if (isPaused()) return;
-  if (!canBreakProgram()) return;
+  if (isPaused()) return true;
+  if (!canBreakProgram()) return true;
+  DCHECK(targetContextGroupId);
+  m_targetContextGroupId = targetContextGroupId;
   v8::debug::BreakRightNow(m_isolate);
+  return m_inspector->enabledDebuggerAgentForGroup(targetContextGroupId);
 }
 
 void V8Debugger::continueProgram(int targetContextGroupId) {

src/inspector/v8-debugger.h

@@ -50,7 +50,7 @@ class V8Debugger : public v8::debug::DebugDelegate {
   v8::debug::ExceptionBreakState getPauseOnExceptionsState();
   void setPauseOnExceptionsState(v8::debug::ExceptionBreakState);
   bool canBreakProgram();
-  void breakProgram();
+  bool breakProgram(int targetContextGroupId);
   void continueProgram(int targetContextGroupId);
 
   void setPauseOnNextStatement(bool, int targetContextGroupId);

test/inspector/debugger/destory-in-break-program-expected.txt

+Check destroying agent inside of breakProgram

test/inspector/debugger/destory-in-break-program.js

+// Copyright 2017 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.
+
+InspectorTest.log('Check destroying agent inside of breakProgram');
+
+(async function test(){
+  await Protocol.Debugger.enable();
+  Protocol.Runtime.evaluate({expression: 'inspector.breakProgram(\'\', \'{}\')'});
+  await Protocol.Debugger.oncePaused();
+  utils.disconnect();
+  utils.quit();
+})();

test/inspector/inspector-impl.cc

@@ -129,18 +129,25 @@ class ConnectTask : public TaskRunner::Task {
 
 class DisconnectTask : public TaskRunner::Task {
  public:
-  explicit DisconnectTask(InspectorClientImpl* client) : client_(client) {}
+  explicit DisconnectTask(InspectorClientImpl* client, bool reset_inspector,
+                          v8::base::Semaphore* ready_semaphore)
+      : client_(client),
+        reset_inspector_(reset_inspector),
+        ready_semaphore_(ready_semaphore) {}
   virtual ~DisconnectTask() = default;
 
   bool is_inspector_task() final { return true; }
 
   void Run(v8::Isolate* isolate,
            const v8::Global<v8::Context>& global_context) {
-    client_->disconnect();
+    client_->disconnect(reset_inspector_);
+    if (ready_semaphore_) ready_semaphore_->Signal();
   }
 
  private:
   InspectorClientImpl* client_;
+  bool reset_inspector_;
+  v8::base::Semaphore* ready_semaphore_;
 };
 
 class CreateContextGroupTask : public TaskRunner::Task {
@@ -217,16 +224,23 @@ void InspectorClientImpl::connect(v8::Local<v8::Context> context) {
 
 void InspectorClientImpl::scheduleReconnect(
     v8::base::Semaphore* ready_semaphore) {
-  task_runner_->Append(new DisconnectTask(this));
+  task_runner_->Append(
+      new DisconnectTask(this, /* reset_inspector */ true, nullptr));
   task_runner_->Append(new ConnectTask(this, ready_semaphore));
 }
 
-void InspectorClientImpl::disconnect() {
+void InspectorClientImpl::scheduleDisconnect(
+    v8::base::Semaphore* ready_semaphore) {
+  task_runner_->Append(
+      new DisconnectTask(this, /* reset_inspector */ false, ready_semaphore));
+}
+
+void InspectorClientImpl::disconnect(bool reset_inspector) {
   for (const auto& it : sessions_) {
     states_[it.first] = it.second->stateJSON();
   }
   sessions_.clear();
-  inspector_.reset();
+  if (reset_inspector) inspector_.reset();
 }
 
 void InspectorClientImpl::scheduleCreateContextGroup(
@@ -359,7 +373,7 @@ class SendMessageToBackendTask : public TaskRunner::Task {
                       ->sessions_[context_group_id_]
                       .get();
       }
-      CHECK(session);
+      if (!session) return;
     }
     v8_inspector::StringView message_view(message_.start(), message_.length());
     session->dispatchProtocolMessage(message_view);

test/inspector/inspector-impl.h

@@ -26,6 +26,7 @@ class InspectorClientImpl : public v8_inspector::V8InspectorClient {
   virtual ~InspectorClientImpl();
 
   void scheduleReconnect(v8::base::Semaphore* ready_semaphore);
+  void scheduleDisconnect(v8::base::Semaphore* ready_semaphore);
   void scheduleCreateContextGroup(
       TaskRunner::SetupGlobalTasks setup_global_tasks,
       v8::base::Semaphore* ready_semaphore, int* context_group_id);
@@ -63,7 +64,7 @@ class InspectorClientImpl : public v8_inspector::V8InspectorClient {
   friend class ConnectTask;
   void connect(v8::Local<v8::Context> context);
   friend class DisconnectTask;
-  void disconnect();
+  void disconnect(bool reset_inspector);
   friend class CreateContextGroupTask;
   int createContextGroup(
       const TaskRunner::SetupGlobalTasks& setup_global_tasks);

test/inspector/inspector-test.cc

@@ -84,6 +84,8 @@ class UtilsExtension : public TaskRunner::SetupGlobalTask {
                    isolate, &UtilsExtension::CancelPauseOnNextStatement));
     utils->Set(ToV8String(isolate, "reconnect"),
                v8::FunctionTemplate::New(isolate, &UtilsExtension::Reconnect));
+    utils->Set(ToV8String(isolate, "disconnect"),
+               v8::FunctionTemplate::New(isolate, &UtilsExtension::Disconnect));
     utils->Set(ToV8String(isolate, "setLogConsoleApiMessageCalls"),
                v8::FunctionTemplate::New(
                    isolate, &UtilsExtension::SetLogConsoleApiMessageCalls));
@@ -264,6 +266,16 @@ class UtilsExtension : public TaskRunner::SetupGlobalTask {
     ready_semaphore.Wait();
   }
 
+  static void Disconnect(const v8::FunctionCallbackInfo<v8::Value>& args) {
+    if (args.Length() != 0) {
+      fprintf(stderr, "Internal error: disconnect().");
+      Exit();
+    }
+    v8::base::Semaphore ready_semaphore(0);
+    inspector_client_->scheduleDisconnect(&ready_semaphore);
+    ready_semaphore.Wait();
+  }
+
   static void SetLogConsoleApiMessageCalls(
       const v8::FunctionCallbackInfo<v8::Value>& args) {
     if (args.Length() != 1 || !args[0]->IsBoolean()) {