chromium/components/keyed_service/core/refcounted_keyed_service.h

// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_KEYED_SERVICE_CORE_REFCOUNTED_KEYED_SERVICE_H_
#define COMPONENTS_KEYED_SERVICE_CORE_REFCOUNTED_KEYED_SERVICE_H_

#include "base/memory/ref_counted.h"
#include "base/task/sequenced_task_runner.h"
#include "base/task/sequenced_task_runner_helpers.h"
#include "components/keyed_service/core/keyed_service_export.h"

class RefcountedKeyedService;

namespace impl {

struct KEYED_SERVICE_EXPORT RefcountedKeyedServiceTraits { … };

}  // namespace impl

// Base class for refcounted objects that hang off the BrowserContext.
//
// The two pass shutdown described in KeyedService works a bit differently
// because there could be outstanding references on other threads.
// ShutdownOnUIThread() will be called on the UI thread, and then the
// destructor will run when the last reference is dropped, which may or may not
// be after the corresponding BrowserContext has been destroyed.
//
// Optionally, if you initialize your service with the constructor that takes a
// SequencedTaskRunner, your service will be deleted on that sequence. We
// can't use content::DeleteOnThread<> directly because RefcountedKeyedService
// must not depend on //content.
class KEYED_SERVICE_EXPORT RefcountedKeyedService
    : public base::RefCountedThreadSafe<RefcountedKeyedService,
                                        impl::RefcountedKeyedServiceTraits> { … };

#endif  // COMPONENTS_KEYED_SERVICE_CORE_REFCOUNTED_KEYED_SERVICE_H_