components/browser_context_keyed_service/browser_context_dependency_manager.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef COMPONENTS_BROWSER_CONTEXT_KEYED_SERVICE_BROWSER_CONTEXT_DEPENDENCY_MANAGER_H_
   6 #define COMPONENTS_BROWSER_CONTEXT_KEYED_SERVICE_BROWSER_CONTEXT_DEPENDENCY_MANAGER_H_
   7
   8 #include "base/memory/singleton.h"
   9 #include "components/browser_context_keyed_service/browser_context_keyed_service_export.h"
  10 #include "components/browser_context_keyed_service/dependency_graph.h"
  11
  12 #ifndef NDEBUG
  13 #include <set>
  14 #endif
  15
  16 class BrowserContextKeyedBaseFactory;
  17
  18 namespace content {
  19 class BrowserContext;
  20 }
  21
  22 // A singleton that listens for context destruction notifications and
  23 // rebroadcasts them to each BrowserContextKeyedBaseFactory in a safe order
  24 // based on the stated dependencies by each service.
  25 class BROWSER_CONTEXT_KEYED_SERVICE_EXPORT BrowserContextDependencyManager {
  26  public:
  27   // Adds/Removes a component from our list of live components. Removing will
  28   // also remove live dependency links.
  29   void AddComponent(BrowserContextKeyedBaseFactory* component);
  30   void RemoveComponent(BrowserContextKeyedBaseFactory* component);
  31
  32   // Adds a dependency between two factories.
  33   void AddEdge(BrowserContextKeyedBaseFactory* depended,
  34                BrowserContextKeyedBaseFactory* dependee);
  35
  36   // Called by each BrowserContext to alert us of its creation. Several services
  37   // want to be started when a context is created. Testing configuration is also
  38   // done at this time. (If you want your BrowserContextKeyedService to be
  39   // started with the BrowserContext, override BrowserContextKeyedBaseFactory::
  40   // ServiceIsCreatedWithBrowserContext() to return true.)
  41   void CreateBrowserContextServices(content::BrowserContext* context,
  42                                     bool is_testing_context);
  43
  44   // Called by each BrowserContext to alert us that we should destroy services
  45   // associated with it.
  46   void DestroyBrowserContextServices(content::BrowserContext* context);
  47
  48 #ifndef NDEBUG
  49   // Debugging assertion called as part of GetServiceForBrowserContext in debug
  50   // mode. This will NOTREACHED() whenever the user is trying to access a stale
  51   // BrowserContext*.
  52   void AssertBrowserContextWasntDestroyed(content::BrowserContext* context);
  53 #endif
  54
  55   static BrowserContextDependencyManager* GetInstance();
  56
  57  private:
  58   friend class BrowserContextDependencyManagerUnittests;
  59   friend struct DefaultSingletonTraits<BrowserContextDependencyManager>;
  60
  61   BrowserContextDependencyManager();
  62   virtual ~BrowserContextDependencyManager();
  63
  64 #ifndef NDEBUG
  65   void DumpBrowserContextDependencies(content::BrowserContext* context);
  66 #endif
  67
  68   DependencyGraph dependency_graph_;
  69
  70 #ifndef NDEBUG
  71   // A list of context objects that have gone through the Shutdown()
  72   // phase. These pointers are most likely invalid, but we keep track of their
  73   // locations in memory so we can nicely assert if we're asked to do anything
  74   // with them.
  75   std::set<content::BrowserContext*> dead_context_pointers_;
  76 #endif
  77 };
  78
  79 #endif  // COMPONENTS_BROWSER_CONTEXT_KEYED_SERVICE_BROWSER_CONTEXT_DEPENDENCY_MANAGER_H_