services/service_manager/background/background_service_manager.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 "services/service_manager/background/background_service_manager.h"

#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/command_line.h"
#include "base/logging.h"
#include "base/memory/ptr_util.h"
#include "base/memory/ref_counted.h"
#include "base/message_loop/message_pump_default.h"
#include "base/path_service.h"
#include "base/run_loop.h"
#include "base/sequenced_task_runner.h"
#include "base/single_thread_task_runner.h"
#include "base/synchronization/waitable_event.h"
#include "base/threading/simple_thread.h"
#include "services/catalog/store.h"
#include "services/service_manager/connect_params.h"
#include "services/service_manager/public/cpp/service.h"
#include "services/service_manager/public/cpp/service_context.h"
#include "services/service_manager/service_manager.h"
#include "services/service_manager/standalone/context.h"

namespace service_manager {
namespace {

// Calls |callback| on |callback_task_runner|'s thread.
void CallCallbackWithIdentity(
    const scoped_refptr<base::TaskRunner> callback_task_runner,
    const base::Callback<void(const Identity&)>& callback,
    const Identity& identity) {
  DCHECK(callback);
  DCHECK(identity.IsValid());
  callback_task_runner->PostTask(FROM_HERE, base::Bind(callback, identity));
}

}  // namespace

BackgroundServiceManager::BackgroundServiceManager(
    service_manager::ServiceProcessLauncherDelegate* launcher_delegate,
    std::unique_ptr<base::Value> catalog_contents)
    : background_thread_("service_manager") {
  background_thread_.Start();
  background_thread_.task_runner()->PostTask(
      FROM_HERE,
      base::Bind(&BackgroundServiceManager::InitializeOnBackgroundThread,
                 base::Unretained(this), launcher_delegate,
                 base::Passed(&catalog_contents)));
}

BackgroundServiceManager::~BackgroundServiceManager() {
  base::WaitableEvent done_event(
      base::WaitableEvent::ResetPolicy::MANUAL,
      base::WaitableEvent::InitialState::NOT_SIGNALED);
  background_thread_.task_runner()->PostTask(
      FROM_HERE,
      base::Bind(&BackgroundServiceManager::ShutDownOnBackgroundThread,
                 base::Unretained(this), &done_event));
  done_event.Wait();
  DCHECK(!context_);
}

void BackgroundServiceManager::StartService(const Identity& identity) {
  background_thread_.task_runner()->PostTask(
      FROM_HERE,
      base::Bind(&BackgroundServiceManager::StartServiceOnBackgroundThread,
                 base::Unretained(this), identity));
}

void BackgroundServiceManager::RegisterService(
    const Identity& identity,
    mojom::ServicePtr service,
    mojom::PIDReceiverRequest pid_receiver_request) {
  mojom::ServicePtrInfo service_info = service.PassInterface();
  background_thread_.task_runner()->PostTask(
      FROM_HERE,
      base::Bind(&BackgroundServiceManager::RegisterServiceOnBackgroundThread,
                 base::Unretained(this), identity, base::Passed(&service_info),
                 base::Passed(&pid_receiver_request)));
}

void BackgroundServiceManager::SetInstanceQuitCallback(
    base::Callback<void(const Identity&)> callback) {
  DCHECK(callback);
  // Hop to the background thread. The provided callback will be called on
  // whichever thread called this function.
  background_thread_.task_runner()->PostTask(
      FROM_HERE,
      base::Bind(
          &BackgroundServiceManager::SetInstanceQuitCallbackOnBackgroundThread,
          base::Unretained(this), base::ThreadTaskRunnerHandle::Get(),
          callback));
}

void BackgroundServiceManager::SetInstanceQuitCallbackOnBackgroundThread(
    const scoped_refptr<base::SingleThreadTaskRunner>& callback_task_runner,
    const base::Callback<void(const Identity&)>& callback) {
  DCHECK(callback_task_runner);
  DCHECK(callback);
  // Calls |callback| with the identity of the service that is quitting.
  context_->service_manager()->SetInstanceQuitCallback(
      base::Bind(&CallCallbackWithIdentity, callback_task_runner, callback));
}

void BackgroundServiceManager::InitializeOnBackgroundThread(
    service_manager::ServiceProcessLauncherDelegate* launcher_delegate,
    std::unique_ptr<base::Value> catalog_contents) {
  context_ =
      base::MakeUnique<Context>(launcher_delegate, std::move(catalog_contents));
}

void BackgroundServiceManager::ShutDownOnBackgroundThread(
    base::WaitableEvent* done_event) {
  context_.reset();
  done_event->Signal();
}

void BackgroundServiceManager::StartServiceOnBackgroundThread(
    const Identity& identity) {
  context_->service_manager()->StartService(identity);
}

void BackgroundServiceManager::RegisterServiceOnBackgroundThread(
    const Identity& identity,
    mojom::ServicePtrInfo service_info,
    mojom::PIDReceiverRequest pid_receiver_request) {
  mojom::ServicePtr service;
  service.Bind(std::move(service_info));
  context_->service_manager()->RegisterService(
      identity, std::move(service), std::move(pid_receiver_request));
}

}  // namespace service_manager