Make nesting/running states a RunLoop rather than a MessageLoop concept.

base/message_loop/message_loop.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/message_loop/message_loop.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 57 matching lines @@
 
 MessageLoop::TaskObserver::TaskObserver() {
 }
 
 MessageLoop::TaskObserver::~TaskObserver() {
 }
 
 MessageLoop::DestructionObserver::~DestructionObserver() {
 }
 
-MessageLoop::NestingObserver::~NestingObserver() {}
-
 //------------------------------------------------------------------------------
 
 MessageLoop::MessageLoop(Type type)
     : MessageLoop(type, MessagePumpFactoryCallback()) {
   BindToCurrentThread();
 }
 
 MessageLoop::MessageLoop(std::unique_ptr<MessagePump> pump)
     : MessageLoop(TYPE_CUSTOM, Bind(&ReturnPump, Passed(&pump))) {
   BindToCurrentThread();
@@ skipping 117 matching lines @@
   DCHECK_EQ(this, current());
   destruction_observers_.AddObserver(destruction_observer);
 }
 
 void MessageLoop::RemoveDestructionObserver(
     DestructionObserver* destruction_observer) {
   DCHECK_EQ(this, current());
   destruction_observers_.RemoveObserver(destruction_observer);
 }
 
-void MessageLoop::AddNestingObserver(NestingObserver* observer) {
-  DCHECK_EQ(this, current());
-  CHECK(allow_nesting_);
-  nesting_observers_.AddObserver(observer);
-}
-
-void MessageLoop::RemoveNestingObserver(NestingObserver* observer) {
-  DCHECK_EQ(this, current());
-  CHECK(allow_nesting_);
-  nesting_observers_.RemoveObserver(observer);
-}
-
 void MessageLoop::QuitWhenIdle() {
   DCHECK_EQ(this, current());
   if (run_loop_) {
     run_loop_->QuitWhenIdle();
   } else {
     NOTREACHED() << "Must be inside Run to call QuitWhenIdle";
   }
 }
 
 void MessageLoop::QuitNow() {
@@ skipping 13 matching lines @@
   MessageLoop::current()->QuitWhenIdle();
 }
 
 // static
 Closure MessageLoop::QuitWhenIdleClosure() {
   return Bind(&QuitCurrentWhenIdle);
 }
 
 void MessageLoop::SetNestableTasksAllowed(bool allowed) {
   if (allowed) {
-    CHECK(allow_nesting_);
+    CHECK(base::RunLoop::IsNestingAllowedOnCurrentThread());
 
     // Kick the native pump just in case we enter a OS-driven nested message
     // loop.
     pump_->ScheduleWork();
   }
   nestable_tasks_allowed_ = allowed;
 }
 
 bool MessageLoop::NestableTasksAllowed() const {
   return nestable_tasks_allowed_;
 }
 
-bool MessageLoop::IsNested() {
-  return run_loop_->run_depth_ > 1;
-}
-
+// TODO(gab): Migrate TaskObservers to RunLoop as part of separating concerns
+// between MessageLoop and RunLoop and making MessageLoop a swappable
+// implementation detail. http://crbug.com/703346
 void MessageLoop::AddTaskObserver(TaskObserver* task_observer) {
   DCHECK_EQ(this, current());
   CHECK(allow_task_observers_);
   task_observers_.AddObserver(task_observer);
 }
 
 void MessageLoop::RemoveTaskObserver(TaskObserver* task_observer) {
   DCHECK_EQ(this, current());
   CHECK(allow_task_observers_);
   task_observers_.RemoveObserver(task_observer);
 }
 
-bool MessageLoop::is_running() const {
-  DCHECK_EQ(this, current());
-  return run_loop_ != NULL;
-}
-
 bool MessageLoop::HasHighResolutionTasks() {
   return incoming_task_queue_->HasHighResolutionTasks();
 }
 
 bool MessageLoop::IsIdleForTesting() {
   // We only check the incoming queue, since we don't want to lock the work
   // queue.
   return incoming_task_queue_->IsIdleForTesting();
 }
 
@@ skipping 70 matching lines @@
   DCHECK_EQ(this, current());
   // Clear the previous thread task runner first, because only one can exist at
   // a time.
   thread_task_runner_handle_.reset();
   thread_task_runner_handle_.reset(new ThreadTaskRunnerHandle(task_runner_));
 }
 
 void MessageLoop::RunHandler() {
   DCHECK_EQ(this, current());
   DCHECK(run_loop_);
-  CHECK(allow_nesting_ || run_loop_->run_depth_ == 1);
   pump_->Run(this);
 }
 
 bool MessageLoop::ProcessNextDelayedNonNestableTask() {
-  if (run_loop_->run_depth_ != 1)
+  if (is_nested_)
     return false;
 
   if (deferred_non_nestable_work_queue_.empty())
     return false;
 
   PendingTask pending_task =
       std::move(deferred_non_nestable_work_queue_.front());
   deferred_non_nestable_work_queue_.pop();
 
   RunTask(&pending_task);
@@ skipping 21 matching lines @@
   task_annotator_.RunTask("MessageLoop::PostTask", pending_task);
   for (auto& observer : task_observers_)
     observer.DidProcessTask(*pending_task);
 
   nestable_tasks_allowed_ = true;
 
   current_pending_task_ = nullptr;
 }
 
 bool MessageLoop::DeferOrRunPendingTask(PendingTask pending_task) {
-  if (pending_task.nestable || run_loop_->run_depth_ == 1) {
+  if (pending_task.nestable || !is_nested_) {
     RunTask(&pending_task);
     // Show that we ran a task (Note: a new one might arrive as a
     // consequence!).
     return true;
   }
 
   // We couldn't run the task now because we're in a nested message loop
   // and the task isn't nestable.
   deferred_non_nestable_work_queue_.push(std::move(pending_task));
   return false;
@@ skipping 45 matching lines @@
 #else
     incoming_task_queue_->ReloadWorkQueue(&work_queue_);
 #endif
   }
 }
 
 void MessageLoop::ScheduleWork() {
   pump_->ScheduleWork();
 }
 
-void MessageLoop::NotifyBeginNestedLoop() {
-  for (auto& observer : nesting_observers_)
-    observer.OnBeginNestedMessageLoop();
-}
-
 bool MessageLoop::DoWork() {
   if (!nestable_tasks_allowed_) {
     // Task can't be executed right now.
     return false;
   }
 
   for (;;) {
     ReloadWorkQueue();
     if (work_queue_.empty())
       break;
@@ skipping 152 matching lines @@
       persistent,
       mode,
       controller,
       delegate);
 }
 #endif
 
 #endif  // !defined(OS_NACL_SFI)
 
 }  // namespace base