Reland "Simplify debugger state."

R=ulan@chromium.org

Review URL: https://codereview.chromium.org/299653002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21378 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/bootstrapper.cc

@@ -2169,20 +2169,18 @@ bool Genesis::InstallSpecialObjects(Handle<Context> native_context) {
 
   // Expose the debug global object in global if a name for it is specified.
   if (FLAG_expose_debug_as != NULL && strlen(FLAG_expose_debug_as) != 0) {
-    Debug* debug = isolate->debug();
     // If loading fails we just bail out without installing the
     // debugger but without tanking the whole context.
+    Debug* debug = isolate->debug();
     if (!debug->Load()) return true;
+    Handle<Context> debug_context = debug->debug_context();
     // Set the security token for the debugger context to the same as
     // the shell native context to allow calling between these (otherwise
     // exposing debug global object doesn't make much sense).
-    debug->debug_context()->set_security_token(
-        native_context->security_token());
-
+    debug_context->set_security_token(native_context->security_token());
     Handle<String> debug_string =
         factory->InternalizeUtf8String(FLAG_expose_debug_as);
-    Handle<Object> global_proxy(
-        debug->debug_context()->global_proxy(), isolate);
+    Handle<Object> global_proxy(debug_context->global_proxy(), isolate);
     RETURN_ON_EXCEPTION_VALUE(
         isolate,
         JSObject::SetLocalPropertyIgnoreAttributes(

src/d8.cc

@@ -753,11 +753,12 @@ void Shell::InstallUtilityScript(Isolate* isolate) {
   // Install the debugger object in the utility scope
   i::Debug* debug = reinterpret_cast<i::Isolate*>(isolate)->debug();
   debug->Load();
+  i::Handle<i::Context> debug_context = debug->debug_context();
   i::Handle<i::JSObject> js_debug
-      = i::Handle<i::JSObject>(debug->debug_context()->global_object());
+      = i::Handle<i::JSObject>(debug_context->global_object());
   utility_context->Global()->Set(String::NewFromUtf8(isolate, "$debug"),
                                  Utils::ToLocal(js_debug));
-  debug->debug_context()->set_security_token(
+  debug_context->set_security_token(
       reinterpret_cast<i::Isolate*>(isolate)->heap()->undefined_value());
 
   // Run the d8 shell utility script in the utility context

src/debug.h

@@ -490,7 +490,6 @@ class Debug {
 
  private:
   explicit Debug(Isolate* isolate);
-  ~Debug();
 
   static bool CompileDebuggerScript(Isolate* isolate, int index);
   void ClearOneShot();
@@ -743,25 +742,6 @@ class LockingCommandMessageQueue BASE_EMBEDDED {
 
 class Debugger {
  public:
-  ~Debugger();
-
-  void DebugRequest(const uint16_t* json_request, int length);
-
-  MUST_USE_RESULT MaybeHandle<Object> MakeJSObject(
-      Vector<const char> constructor_name,
-      int argc,
-      Handle<Object> argv[]);
-  MUST_USE_RESULT MaybeHandle<Object> MakeExecutionState();
-  MUST_USE_RESULT MaybeHandle<Object> MakeBreakEvent(
-      Handle<Object> break_points_hit);
-  MUST_USE_RESULT MaybeHandle<Object> MakeExceptionEvent(
-      Handle<Object> exception,
-      bool uncaught,
-      Handle<Object> promise);
-  MUST_USE_RESULT MaybeHandle<Object> MakeCompileEvent(
-      Handle<Script> script, bool before);
-  MUST_USE_RESULT MaybeHandle<Object> MakeScriptCollectedEvent(int id);
-
   void OnDebugBreak(Handle<Object> break_points_hit, bool auto_continue);
   void OnException(Handle<Object> exception, bool uncaught);
   void OnBeforeCompile(Handle<Script> script);
@@ -773,13 +753,7 @@ class Debugger {
   void OnAfterCompile(Handle<Script> script,
                       AfterCompileFlags after_compile_flags);
   void OnScriptCollected(int id);
-  void ProcessDebugEvent(v8::DebugEvent event,
-                         Handle<JSObject> event_data,
-                         bool auto_continue);
-  void NotifyMessageHandler(v8::DebugEvent event,
-                            Handle<JSObject> exec_state,
-                            Handle<JSObject> event_data,
-                            bool auto_continue);
+
   void SetEventListener(Handle<Object> callback, Handle<Object> data);
   void SetMessageHandler(v8::Debug::MessageHandler handler);
 
@@ -798,36 +772,13 @@ class Debugger {
 
   Handle<Context> GetDebugContext();
 
-  // Unload the debugger if possible. Only called when no debugger is currently
-  // active.
-  void UnloadDebugger();
-  friend void ForceUnloadDebugger();  // In test-debug.cc
-
-  inline bool EventActive() {
-    LockGuard<RecursiveMutex> lock_guard(&debugger_access_);
-
-    // Check whether the message handler was been cleared.
-    // TODO(yangguo): handle loading and unloading of the debugger differently.
-    if (debugger_unload_pending_) {
-      if (isolate_->debug()->debugger_entry() == NULL) {
-        UnloadDebugger();
-      }
-    }
-
-    // Currently argument event is not used.
-    return !ignore_debugger_ && is_active_;
-  }
-
   bool ignore_debugger() const { return ignore_debugger_; }
   void set_live_edit_enabled(bool v) { live_edit_enabled_ = v; }
   bool live_edit_enabled() const {
     return FLAG_enable_liveedit && live_edit_enabled_ ;
   }
 
-  bool is_active() {
-    LockGuard<RecursiveMutex> lock_guard(&debugger_access_);
-    return is_active_;
-  }
+  bool is_active() { return is_active_; }
 
   class IgnoreScope {
    public:
@@ -849,6 +800,22 @@ class Debugger {
 
  private:
   explicit Debugger(Isolate* isolate);
+  ~Debugger();
+
+  MUST_USE_RESULT MaybeHandle<Object> MakeJSObject(
+      Vector<const char> constructor_name,
+      int argc,
+      Handle<Object> argv[]);
+  MUST_USE_RESULT MaybeHandle<Object> MakeExecutionState();
+  MUST_USE_RESULT MaybeHandle<Object> MakeBreakEvent(
+      Handle<Object> break_points_hit);
+  MUST_USE_RESULT MaybeHandle<Object> MakeExceptionEvent(
+      Handle<Object> exception,
+      bool uncaught,
+      Handle<Object> promise);
+  MUST_USE_RESULT MaybeHandle<Object> MakeCompileEvent(
+      Handle<Script> script, bool before);
+  MUST_USE_RESULT MaybeHandle<Object> MakeScriptCollectedEvent(int id);
 
   void CallEventCallback(v8::DebugEvent event,
                          Handle<Object> exec_state,
@@ -861,18 +828,31 @@ class Debugger {
   void CallJSEventCallback(v8::DebugEvent event,
                            Handle<Object> exec_state,
                            Handle<Object> event_data);
-  void ListenersChanged();
+  void UpdateState();
+
+  void ProcessDebugEvent(v8::DebugEvent event,
+                         Handle<JSObject> event_data,
+                         bool auto_continue);
+  void NotifyMessageHandler(v8::DebugEvent event,
+                            Handle<JSObject> exec_state,
+                            Handle<JSObject> event_data,
+                            bool auto_continue);
 
   // Invoke the message handler function.
   void InvokeMessageHandler(MessageImpl message);
 
-  RecursiveMutex debugger_access_;  // Mutex guarding debugger variables.
+  inline bool EventActive() {
+    // Check whether the message handler was been cleared.
+    // TODO(yangguo): handle loading and unloading of the debugger differently.
+    // Currently argument event is not used.
+    return !ignore_debugger_ && is_active_;
+  }
+
   Handle<Object> event_listener_;  // Global handle to listener.
   Handle<Object> event_listener_data_;
   bool is_active_;
   bool ignore_debugger_;  // Are we temporarily ignoring the debugger?
   bool live_edit_enabled_;  // Enable LiveEdit.
-  bool never_unload_debugger_;  // Can we unload the debugger?
   v8::Debug::MessageHandler message_handler_;
   bool debugger_unload_pending_;  // Was message handler cleared?
 
@@ -911,8 +891,7 @@ class EnterDebugger BASE_EMBEDDED {
  private:
   Isolate* isolate_;
   EnterDebugger* prev_;  // Previous debugger entry if entered recursively.
-  JavaScriptFrameIterator it_;
-  const bool has_js_frames_;  // Were there any JavaScript frames?
+  bool has_js_frames_;  // Were there any JavaScript frames?
   StackFrame::Id break_frame_id_;  // Previous break frame id.
   int break_id_;  // Previous break id.
   bool load_failed_;  // Did the debugger fail to load?

src/execution.cc

@@ -692,9 +692,6 @@ void Execution::DebugBreakHelper(Isolate* isolate) {
 
 void Execution::ProcessDebugMessages(Isolate* isolate,
                                      bool debug_command_only) {
-  // Assert that we are on the main thread of the isolate.
-  ASSERT(ThreadId::Current().Equals(isolate->thread_id()));
-
   isolate->stack_guard()->ClearDebugCommand();
 
   StackLimitCheck check(isolate);

src/isolate.cc

@@ -1558,8 +1558,6 @@ void Isolate::Deinit() {
   if (state_ == INITIALIZED) {
     TRACE_ISOLATE(deinit);
 
-    debugger()->UnloadDebugger();
-
     if (concurrent_recompilation_enabled()) {
       optimizing_compiler_thread_->Stop();
       delete optimizing_compiler_thread_;

src/runtime.cc

@@ -11044,8 +11044,9 @@ RUNTIME_FUNCTION(Runtime_DebugIndexedInterceptorElementValue) {
 
 
 static bool CheckExecutionState(Isolate* isolate, int break_id) {
-  return (isolate->debug()->break_id() != 0 &&
-          break_id == isolate->debug()->break_id());
+  return !isolate->debug()->debug_context().is_null() &&
+         isolate->debug()->break_id() != 0 &&
+         isolate->debug()->break_id() == break_id;
 }
 
 

test/cctest/test-debug.cc

@@ -98,10 +98,11 @@ class DebugLocalContext {
     v8::internal::Isolate* isolate =
         reinterpret_cast<v8::internal::Isolate*>(context_->GetIsolate());
     v8::internal::Factory* factory = isolate->factory();
-    v8::internal::Debug* debug = isolate->debug();
     // Expose the debug context global object in the global object for testing.
-    debug->Load();
-    debug->debug_context()->set_security_token(
+    CHECK(isolate->debug()->Load());
+    Handle<v8::internal::Context> debug_context =
+        isolate->debug()->debug_context();
+    debug_context->set_security_token(
         v8::Utils::OpenHandle(*context_)->security_token());
 
     Handle<JSGlobalProxy> global(Handle<JSGlobalProxy>::cast(
@@ -109,7 +110,7 @@ class DebugLocalContext {
     Handle<v8::internal::String> debug_string =
         factory->InternalizeOneByteString(STATIC_ASCII_VECTOR("debug"));
     v8::internal::Runtime::SetObjectProperty(isolate, global, debug_string,
-        Handle<Object>(debug->debug_context()->global_proxy(), isolate),
+        Handle<Object>(debug_context->global_proxy(), isolate),
         DONT_ENUM,
         ::v8::internal::SLOPPY).Check();
   }
@@ -421,12 +422,6 @@ void CheckDebuggerUnloaded(bool check_functions) {
 }
 
 
-void ForceUnloadDebugger() {
-  CcTest::i_isolate()->debugger()->never_unload_debugger_ = false;
-  CcTest::i_isolate()->debugger()->UnloadDebugger();
-}
-
-
 } }  // namespace v8::internal
 
 
@@ -5500,13 +5495,12 @@ static void CheckDataParameter(
       v8::String::NewFromUtf8(args.GetIsolate(), "Test");
   CHECK(v8::Debug::Call(debugger_call_with_data, data)->IsString());
 
-  CHECK(v8::Debug::Call(debugger_call_with_data).IsEmpty());
-  CHECK(v8::Debug::Call(debugger_call_with_data).IsEmpty());
-
-  v8::TryCatch catcher;
-  v8::Debug::Call(debugger_call_with_data);
-  CHECK(catcher.HasCaught());
-  CHECK(catcher.Exception()->IsString());
+  for (int i = 0; i < 3; i++) {
+    v8::TryCatch catcher;
+    CHECK(v8::Debug::Call(debugger_call_with_data).IsEmpty());
+    CHECK(catcher.HasCaught());
+    CHECK(catcher.Exception()->IsString());
+  }
 }
 
 
@@ -6872,9 +6866,12 @@ TEST(CallingContextIsNotDebugContext) {
 
 TEST(DebugContextIsPreservedBetweenAccesses) {
   v8::HandleScope scope(CcTest::isolate());
+  v8::Debug::SetDebugEventListener(DebugEventBreakPointHitCount);
   v8::Local<v8::Context> context1 = v8::Debug::GetDebugContext();
   v8::Local<v8::Context> context2 = v8::Debug::GetDebugContext();
-  CHECK_EQ(*context1, *context2);
+  CHECK(v8::Utils::OpenHandle(*context1).is_identical_to(
+            v8::Utils::OpenHandle(*context2)));
+  v8::Debug::SetDebugEventListener(NULL);
 }
 
 

test/cctest/test-heap-profiler.cc

@@ -1888,7 +1888,7 @@ TEST(NoDebugObjectInSnapshot) {
   v8::HandleScope scope(env->GetIsolate());
   v8::HeapProfiler* heap_profiler = env->GetIsolate()->GetHeapProfiler();
 
-  CcTest::i_isolate()->debug()->Load();
+  CHECK(CcTest::i_isolate()->debug()->Load());
   CompileRun("foo = {};");
   const v8::HeapSnapshot* snapshot =
       heap_profiler->TakeHeapSnapshot(v8_str("snapshot"));

test/mjsunit/debug-stepin-positions.js

@@ -37,12 +37,13 @@ function TestCase(fun, frame_number) {
   var exception = false;
   var codeSnippet = undefined;
   var resultPositions = undefined;
+  var step = 0;
 
   function listener(event, exec_state, event_data, data) {
     try {
       if (event == Debug.DebugEvent.Break ||
           event == Debug.DebugEvent.Exception) {
-        Debug.setListener(null);
+        if (step++ > 0) return;
         assertHasLineMark(/pause/, exec_state.frame(0));
         assertHasLineMark(/positions/, exec_state.frame(frame_number));
         var frame = exec_state.frame(frame_number);