// Copyright 2019 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 "content/browser/scheduler/browser_ui_thread_scheduler.h"

#include <utility>

#include "base/feature_list.h"
#include "base/logging.h"
#include "base/memory/ptr_util.h"
#include "base/message_loop/message_pump.h"
#include "base/message_loop/message_pump_type.h"
#include "base/process/process.h"
#include "base/run_loop.h"
#include "base/task/sequence_manager/sequence_manager.h"
#include "base/task/sequence_manager/sequence_manager_impl.h"
#include "base/task/sequence_manager/task_queue.h"
#include "base/task/sequence_manager/time_domain.h"
#include "base/threading/platform_thread.h"
#include "build/build_config.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/common/content_features.h"

namespace content {

BrowserUIThreadScheduler::~BrowserUIThreadScheduler() = default;

// static
std::unique_ptr<BrowserUIThreadScheduler>
BrowserUIThreadScheduler::CreateForTesting(
    base::sequence_manager::SequenceManager* sequence_manager,
    base::sequence_manager::TimeDomain* time_domain) {
  return base::WrapUnique(
      new BrowserUIThreadScheduler(sequence_manager, time_domain));
}

BrowserUIThreadScheduler::BrowserUIThreadScheduler()
    : owned_sequence_manager_(
          base::sequence_manager::CreateUnboundSequenceManager(
              base::sequence_manager::SequenceManager::Settings::Builder()
                  .SetMessagePumpType(base::MessagePumpType::UI)
                  .SetAntiStarvationLogicForPrioritiesDisabled(true)
                  .Build())),
      task_queues_(BrowserThread::UI,
                   owned_sequence_manager_.get(),
                   owned_sequence_manager_->GetRealTimeDomain()),
      handle_(task_queues_.GetHandle()) {
  CommonSequenceManagerSetup(owned_sequence_manager_.get());
  owned_sequence_manager_->SetDefaultTaskRunner(
      handle_->GetDefaultTaskRunner());

  owned_sequence_manager_->BindToMessagePump(
      base::MessagePump::Create(base::MessagePumpType::UI));
}

BrowserUIThreadScheduler::BrowserUIThreadScheduler(
    base::sequence_manager::SequenceManager* sequence_manager,
    base::sequence_manager::TimeDomain* time_domain)
    : task_queues_(BrowserThread::UI, sequence_manager, time_domain),
      handle_(task_queues_.GetHandle()) {
  CommonSequenceManagerSetup(sequence_manager);
}

void BrowserUIThreadScheduler::CommonSequenceManagerSetup(
    base::sequence_manager::SequenceManager* sequence_manager) {
  sequence_manager_ = sequence_manager;
  sequence_manager_->EnableCrashKeys("ui_scheduler_async_stack");
}

const scoped_refptr<base::SequencedTaskRunner>&
BrowserUIThreadScheduler::GetTaskRunnerForCurrentTask() const {
  DCHECK(sequence_manager_);
  return sequence_manager_->GetTaskRunnerForCurrentTask();
}

}  // namespace content