Support FileDescriptorWatcher in TaskScheduler.

base/task_scheduler/task_scheduler_impl.cc

 // Copyright 2016 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/task_scheduler/task_scheduler_impl.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/memory/ptr_util.h"
+#include "base/task_scheduler/delayed_task_manager.h"
 #include "base/task_scheduler/scheduler_worker_pool_params.h"
 #include "base/task_scheduler/sequence_sort_key.h"
 #include "base/task_scheduler/task.h"
+#include "base/task_scheduler/task_tracker.h"
 #include "base/time/time.h"
+#include "build/build_config.h"
+
+#if defined(OS_POSIX) && !defined(OS_NACL_SFI)

[robliao, 2016/10/20 00:59:40]

Worth commenting that we don't support NaCl.
Also, is defined(OS_NACL) sufficient?

[fdoray, 2016/10/21 12:29:43]

Added comment in task_tracker_posix.h and in TaskSchedulerImpl::Initialize
below.
We do support OS_NACL_NON_SFI.

+#include "base/task_scheduler/task_tracker_posix.h"
+#endif
 
 namespace base {
 namespace internal {
 
 // static
 std::unique_ptr<TaskSchedulerImpl> TaskSchedulerImpl::Create(
     const std::vector<SchedulerWorkerPoolParams>& worker_pool_params_vector,
     const WorkerPoolIndexForTraitsCallback&
         worker_pool_index_for_traits_callback) {
   std::unique_ptr<TaskSchedulerImpl> scheduler(
@@ skipping 20 matching lines @@
 
 scoped_refptr<TaskRunner> TaskSchedulerImpl::CreateTaskRunnerWithTraits(
     const TaskTraits& traits,
     ExecutionMode execution_mode) {
   return GetWorkerPoolForTraits(traits)->CreateTaskRunnerWithTraits(
       traits, execution_mode);
 }
 
 void TaskSchedulerImpl::Shutdown() {
   // TODO(fdoray): Increase the priority of BACKGROUND tasks blocking shutdown.
-  task_tracker_.Shutdown();
+  DCHECK(task_tracker_);
+  task_tracker_->Shutdown();
 }
 
 void TaskSchedulerImpl::FlushForTesting() {
-  task_tracker_.Flush();
+  DCHECK(task_tracker_);
+  task_tracker_->Flush();
 }
 
 void TaskSchedulerImpl::JoinForTesting() {
 #if DCHECK_IS_ON()
   DCHECK(!join_for_testing_returned_.IsSet());
 #endif
   for (const auto& worker_pool : worker_pools_)
     worker_pool->JoinForTesting();
   service_thread_.Stop();
 #if DCHECK_IS_ON()
@@ skipping 18 matching lines @@
   constexpr MessageLoop::Type kServiceThreadMessageLoopType =
 #if defined(OS_POSIX)
       MessageLoop::TYPE_IO;
 #else
       MessageLoop::TYPE_DEFAULT;
 #endif
   constexpr size_t kDefaultStackSize = 0;
   CHECK(service_thread_.StartWithOptions(
       Thread::Options(kServiceThreadMessageLoopType, kDefaultStackSize)));
 
-  // Instantiate the DelayedTaskManager. The service thread must be started
-  // before its TaskRunner is available.
+  // Instantiate TaskTracker and DelayedTaskManager after starting the service
+  // thread. The service thread MessageLoopForIO and TaskRunner aren't available
+  // before that.
+  task_tracker_ =
+#if defined(OS_POSIX) && !defined(OS_NACL_SFI)
+      base::MakeUnique<TaskTrackerPosix>(
+          static_cast<MessageLoopForIO*>(service_thread_.message_loop()));
+#else
+      base::MakeUnique<TaskTracker>();
+#endif
   delayed_task_manager_ =
       base::MakeUnique<DelayedTaskManager>(service_thread_.task_runner());
 
   const SchedulerWorkerPoolImpl::ReEnqueueSequenceCallback
       re_enqueue_sequence_callback =
           Bind(&TaskSchedulerImpl::ReEnqueueSequenceCallback, Unretained(this));
 
   // Start worker pools.
   for (const auto& worker_pool_params : worker_pool_params_vector) {
     // Passing pointers to objects owned by |this| to
     // SchedulerWorkerPoolImpl::Create() is safe because a TaskSchedulerImpl
     // can't be deleted before all its worker pools have been joined.
     worker_pools_.push_back(SchedulerWorkerPoolImpl::Create(
-        worker_pool_params, re_enqueue_sequence_callback, &task_tracker_,
+        worker_pool_params, re_enqueue_sequence_callback, task_tracker_.get(),
         delayed_task_manager_.get()));
     CHECK(worker_pools_.back());
   }
 }
 
 SchedulerWorkerPool* TaskSchedulerImpl::GetWorkerPoolForTraits(
     const TaskTraits& traits) {
   const size_t index = worker_pool_index_for_traits_callback_.Run(traits);
   DCHECK_LT(index, worker_pools_.size());
   return worker_pools_[index].get();
@@ skipping 10 matching lines @@
   // in |sequence|.
   const TaskTraits traits =
       sequence->PeekTaskTraits().WithPriority(sort_key.priority());
 
   GetWorkerPoolForTraits(traits)->ReEnqueueSequence(std::move(sequence),
                                                     sort_key);
 }
 
 }  // namespace internal
 }  // namespace base