| // Copyright (c) 2012 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. |
| |
| #ifndef COMPONENTS_BROWSER_CONTEXT_KEYED_SERVICE_REFCOUNTED_BROWSER_CONTEXT_KEYED_SERVICE_H_ |
| #define COMPONENTS_BROWSER_CONTEXT_KEYED_SERVICE_REFCOUNTED_BROWSER_CONTEXT_KEYED_SERVICE_H_ |
| |
| #include "base/memory/ref_counted.h" |
| #include "base/sequenced_task_runner_helpers.h" |
| #include "components/browser_context_keyed_service/browser_context_keyed_service_export.h" |
| #include "content/public/browser/browser_thread.h" |
| |
| class RefcountedBrowserContextKeyedService; |
| |
| namespace impl { |
| |
| struct BROWSER_CONTEXT_KEYED_SERVICE_EXPORT |
| RefcountedBrowserContextKeyedServiceTraits { |
| static void Destruct(const RefcountedBrowserContextKeyedService* obj); |
| }; |
| |
| } // namespace impl |
| |
| // Base class for refcounted objects that hang off the BrowserContext. |
| // |
| // The two pass shutdown described in BrowserContextKeyedService 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 |
| // thread ID, your service will be deleted on that thread. We can't use |
| // content::DeleteOnThread<> directly because |
| // RefcountedBrowserContextKeyedService must be one type that |
| // RefcountedBrowserContextKeyedServiceFactory can use. |
| class BROWSER_CONTEXT_KEYED_SERVICE_EXPORT RefcountedBrowserContextKeyedService |
| : public base::RefCountedThreadSafe< |
| RefcountedBrowserContextKeyedService, |
| impl::RefcountedBrowserContextKeyedServiceTraits> { |
| public: |
| // Unlike BrowserContextKeyedService, ShutdownOnUI is not optional. You must |
| // do something to drop references during the first pass Shutdown() because |
| // this is the only point where you are guaranteed that something is running |
| // on the UI thread. The PKSF framework will ensure that this is only called |
| // on the UI thread; you do not need to check for that yourself. |
| virtual void ShutdownOnUIThread() = 0; |
| |
| protected: |
| // If your service does not need to be deleted on a specific thread, use the |
| // default constructor. |
| RefcountedBrowserContextKeyedService(); |
| |
| // If you need your service to be deleted on a specific thread (for example, |
| // you're converting a service that used content::DeleteOnThread<IO>), then |
| // use this constructor with the ID of the thread. |
| explicit RefcountedBrowserContextKeyedService( |
| const content::BrowserThread::ID thread_id); |
| |
| // The second pass destruction can happen anywhere unless you specify which |
| // thread this service must be destroyed on by using the second constructor. |
| virtual ~RefcountedBrowserContextKeyedService(); |
| |
| private: |
| friend struct impl::RefcountedBrowserContextKeyedServiceTraits; |
| friend class base::DeleteHelper<RefcountedBrowserContextKeyedService>; |
| friend class base::RefCountedThreadSafe<RefcountedBrowserContextKeyedService, |
| impl::RefcountedBrowserContextKeyedServiceTraits>; |
| |
| // Do we have to delete this object on a specific thread? |
| bool requires_destruction_on_thread_; |
| content::BrowserThread::ID thread_id_; |
| }; |
| |
| #endif // COMPONENTS_BROWSER_CONTEXT_KEYED_SERVICE_REFCOUNTED_BROWSER_CONTEXT_KEYED_SERVICE_H_ |