extensions/browser/api/api_resource_manager.h

   1 // Copyright 2014 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 EXTENSIONS_BROWSER_API_API_RESOURCE_MANAGER_H_
   6 #define EXTENSIONS_BROWSER_API_API_RESOURCE_MANAGER_H_
   7
   8 #include <map>
   9
  10 #include "base/containers/hash_tables.h"
  11 #include "base/memory/linked_ptr.h"
  12 #include "base/memory/ref_counted.h"
  13 #include "base/scoped_observer.h"
  14 #include "base/threading/non_thread_safe.h"
  15 #include "components/keyed_service/core/keyed_service.h"
  16 #include "content/public/browser/browser_thread.h"
  17 #include "extensions/browser/browser_context_keyed_api_factory.h"
  18 #include "extensions/browser/extension_registry.h"
  19 #include "extensions/browser/extension_registry_observer.h"
  20 #include "extensions/browser/process_manager.h"
  21 #include "extensions/browser/process_manager_observer.h"
  22 #include "extensions/common/extension.h"
  23
  24 namespace extensions {
  25
  26 namespace core_api {
  27 class BluetoothSocketApiFunction;
  28 class BluetoothSocketEventDispatcher;
  29 class SerialEventDispatcher;
  30 class TCPServerSocketEventDispatcher;
  31 class TCPSocketEventDispatcher;
  32 class UDPSocketEventDispatcher;
  33 }
  34
  35 template <typename T>
  36 struct NamedThreadTraits {
  37   static bool IsCalledOnValidThread() {
  38     return content::BrowserThread::CurrentlyOn(T::kThreadId);
  39   }
  40
  41   static bool IsMessageLoopValid() {
  42     return content::BrowserThread::IsMessageLoopValid(T::kThreadId);
  43   }
  44
  45   static scoped_refptr<base::SequencedTaskRunner> GetSequencedTaskRunner() {
  46     return content::BrowserThread::GetMessageLoopProxyForThread(T::kThreadId);
  47   }
  48 };
  49
  50 template <typename T>
  51 struct TestThreadTraits {
  52   static bool IsCalledOnValidThread() {
  53     return content::BrowserThread::CurrentlyOn(thread_id_);
  54   }
  55
  56   static bool IsMessageLoopValid() {
  57     return content::BrowserThread::IsMessageLoopValid(thread_id_);
  58   }
  59
  60   static scoped_refptr<base::SequencedTaskRunner> GetSequencedTaskRunner() {
  61     return content::BrowserThread::GetMessageLoopProxyForThread(thread_id_);
  62   }
  63
  64   static content::BrowserThread::ID thread_id_;
  65 };
  66
  67 template <typename T>
  68 content::BrowserThread::ID TestThreadTraits<T>::thread_id_ =
  69     content::BrowserThread::IO;
  70
  71 // An ApiResourceManager manages the lifetime of a set of resources that
  72 // that live on named threads (i.e. BrowserThread::IO) which ApiFunctions use.
  73 // Examples of such resources are sockets or USB connections.
  74 //
  75 // Users of this class should define kThreadId to be the thread that
  76 // ApiResourceManager to works on. The default is defined in ApiResource.
  77 // The user must also define a static const char* service_name() that returns
  78 // the name of the service, and in order for ApiResourceManager to use
  79 // service_name() friend this class.
  80 //
  81 // In the cc file the user must define a GetFactoryInstance() and manage their
  82 // own instances (typically using LazyInstance or Singleton).
  83 //
  84 // E.g.:
  85 //
  86 // class Resource {
  87 //  public:
  88 //   static const BrowserThread::ID kThreadId = BrowserThread::FILE;
  89 //  private:
  90 //   friend class ApiResourceManager<Resource>;
  91 //   static const char* service_name() {
  92 //     return "ResourceManager";
  93 //    }
  94 // };
  95 //
  96 // In the cc file:
  97 //
  98 // static base::LazyInstance<BrowserContextKeyedAPIFactory<
  99 //     ApiResourceManager<Resource> > >
 100 //         g_factory = LAZY_INSTANCE_INITIALIZER;
 101 //
 102 //
 103 // template <>
 104 // BrowserContextKeyedAPIFactory<ApiResourceManager<Resource> >*
 105 // ApiResourceManager<Resource>::GetFactoryInstance() {
 106 //   return g_factory.Pointer();
 107 // }
 108 template <class T, typename ThreadingTraits = NamedThreadTraits<T>>
 109 class ApiResourceManager : public BrowserContextKeyedAPI,
 110                            public base::NonThreadSafe,
 111                            public ExtensionRegistryObserver,
 112                            public ProcessManagerObserver {
 113  public:
 114   explicit ApiResourceManager(content::BrowserContext* context)
 115       : data_(new ApiResourceData()),
 116         extension_registry_observer_(this),
 117         process_manager_observer_(this) {
 118     extension_registry_observer_.Add(ExtensionRegistry::Get(context));
 119     process_manager_observer_.Add(ProcessManager::Get(context));
 120   }
 121   // For Testing.
 122   static ApiResourceManager<T, TestThreadTraits<T> >*
 123   CreateApiResourceManagerForTest(content::BrowserContext* context,
 124                                   content::BrowserThread::ID thread_id) {
 125     TestThreadTraits<T>::thread_id_ = thread_id;
 126     ApiResourceManager<T, TestThreadTraits<T> >* manager =
 127         new ApiResourceManager<T, TestThreadTraits<T> >(context);
 128     return manager;
 129   }
 130
 131   virtual ~ApiResourceManager() {
 132     DCHECK(CalledOnValidThread());
 133     DCHECK(ThreadingTraits::IsMessageLoopValid())
 134         << "A unit test is using an ApiResourceManager but didn't provide "
 135            "the thread message loop needed for that kind of resource. "
 136            "Please ensure that the appropriate message loop is operational.";
 137
 138     data_->InititateCleanup();
 139   }
 140
 141   // Takes ownership.
 142   int Add(T* api_resource) { return data_->Add(api_resource); }
 143
 144   void Remove(const std::string& extension_id, int api_resource_id) {
 145     data_->Remove(extension_id, api_resource_id);
 146   }
 147
 148   T* Get(const std::string& extension_id, int api_resource_id) {
 149     return data_->Get(extension_id, api_resource_id);
 150   }
 151
 152   base::hash_set<int>* GetResourceIds(const std::string& extension_id) {
 153     return data_->GetResourceIds(extension_id);
 154   }
 155
 156   // BrowserContextKeyedAPI implementation.
 157   static BrowserContextKeyedAPIFactory<ApiResourceManager<T> >*
 158       GetFactoryInstance();
 159
 160   // Convenience method to get the ApiResourceManager for a profile.
 161   static ApiResourceManager<T>* Get(content::BrowserContext* context) {
 162     return BrowserContextKeyedAPIFactory<ApiResourceManager<T> >::Get(context);
 163   }
 164
 165   // BrowserContextKeyedAPI implementation.
 166   static const char* service_name() { return T::service_name(); }
 167
 168   // Change the resource mapped to this |extension_id| at this
 169   // |api_resource_id| to |resource|. Returns true and succeeds unless
 170   // |api_resource_id| does not already identify a resource held by
 171   // |extension_id|.
 172   bool Replace(const std::string& extension_id,
 173                int api_resource_id,
 174                T* resource) {
 175     return data_->Replace(extension_id, api_resource_id, resource);
 176   }
 177
 178  protected:
 179   // ProcessManagerObserver:
 180   void OnBackgroundHostClose(const std::string& extension_id) override {
 181     data_->InitiateExtensionSuspendedCleanup(extension_id);
 182   }
 183
 184   // ExtensionRegistryObserver:
 185   void OnExtensionUnloaded(content::BrowserContext* browser_context,
 186                            const Extension* extension,
 187                            UnloadedExtensionInfo::Reason reason) override {
 188     data_->InitiateExtensionUnloadedCleanup(extension->id());
 189   }
 190
 191  private:
 192   // TODO(rockot): ApiResourceData could be moved out of ApiResourceManager and
 193   // we could avoid maintaining a friends list here.
 194   friend class BluetoothAPI;
 195   friend class core_api::BluetoothSocketApiFunction;
 196   friend class core_api::BluetoothSocketEventDispatcher;
 197   friend class core_api::SerialEventDispatcher;
 198   friend class core_api::TCPServerSocketEventDispatcher;
 199   friend class core_api::TCPSocketEventDispatcher;
 200   friend class core_api::UDPSocketEventDispatcher;
 201   friend class BrowserContextKeyedAPIFactory<ApiResourceManager<T> >;
 202
 203   static const bool kServiceHasOwnInstanceInIncognito = true;
 204   static const bool kServiceIsNULLWhileTesting = true;
 205
 206   // ApiResourceData class handles resource bookkeeping on a thread
 207   // where resource lifetime is handled.
 208   class ApiResourceData : public base::RefCountedThreadSafe<ApiResourceData> {
 209    public:
 210     typedef std::map<int, linked_ptr<T> > ApiResourceMap;
 211     // Lookup map from extension id's to allocated resource id's.
 212     typedef std::map<std::string, base::hash_set<int> > ExtensionToResourceMap;
 213
 214     ApiResourceData() : next_id_(1) {}
 215
 216     int Add(T* api_resource) {
 217       DCHECK(ThreadingTraits::IsCalledOnValidThread());
 218       int id = GenerateId();
 219       if (id > 0) {
 220         linked_ptr<T> resource_ptr(api_resource);
 221         api_resource_map_[id] = resource_ptr;
 222
 223         const std::string& extension_id = api_resource->owner_extension_id();
 224         ExtensionToResourceMap::iterator it =
 225             extension_resource_map_.find(extension_id);
 226         if (it == extension_resource_map_.end()) {
 227           it = extension_resource_map_.insert(
 228               std::make_pair(extension_id, base::hash_set<int>())).first;
 229         }
 230         it->second.insert(id);
 231         return id;
 232       }
 233       return 0;
 234     }
 235
 236     void Remove(const std::string& extension_id, int api_resource_id) {
 237       DCHECK(ThreadingTraits::IsCalledOnValidThread());
 238       if (GetOwnedResource(extension_id, api_resource_id)) {
 239         ExtensionToResourceMap::iterator it =
 240             extension_resource_map_.find(extension_id);
 241         it->second.erase(api_resource_id);
 242         api_resource_map_.erase(api_resource_id);
 243       }
 244     }
 245
 246     T* Get(const std::string& extension_id, int api_resource_id) {
 247       DCHECK(ThreadingTraits::IsCalledOnValidThread());
 248       return GetOwnedResource(extension_id, api_resource_id);
 249     }
 250
 251     // Change the resource mapped to this |extension_id| at this
 252     // |api_resource_id| to |resource|. Returns true and succeeds unless
 253     // |api_resource_id| does not already identify a resource held by
 254     // |extension_id|.
 255     bool Replace(const std::string& extension_id,
 256                  int api_resource_id,
 257                  T* api_resource) {
 258       DCHECK(ThreadingTraits::IsCalledOnValidThread());
 259       T* old_resource = api_resource_map_[api_resource_id].get();
 260       if (old_resource && extension_id == old_resource->owner_extension_id()) {
 261         api_resource_map_[api_resource_id] = linked_ptr<T>(api_resource);
 262         return true;
 263       }
 264       return false;
 265     }
 266
 267     base::hash_set<int>* GetResourceIds(const std::string& extension_id) {
 268       DCHECK(ThreadingTraits::IsCalledOnValidThread());
 269       return GetOwnedResourceIds(extension_id);
 270     }
 271
 272     void InitiateExtensionUnloadedCleanup(const std::string& extension_id) {
 273       if (ThreadingTraits::IsCalledOnValidThread()) {
 274         CleanupResourcesFromUnloadedExtension(extension_id);
 275       } else {
 276         ThreadingTraits::GetSequencedTaskRunner()->PostTask(
 277             FROM_HERE,
 278             base::Bind(&ApiResourceData::CleanupResourcesFromUnloadedExtension,
 279                        this,
 280                        extension_id));
 281       }
 282     }
 283
 284     void InitiateExtensionSuspendedCleanup(const std::string& extension_id) {
 285       if (ThreadingTraits::IsCalledOnValidThread()) {
 286         CleanupResourcesFromSuspendedExtension(extension_id);
 287       } else {
 288         ThreadingTraits::GetSequencedTaskRunner()->PostTask(
 289             FROM_HERE,
 290             base::Bind(&ApiResourceData::CleanupResourcesFromSuspendedExtension,
 291                        this,
 292                        extension_id));
 293       }
 294     }
 295
 296     void InititateCleanup() {
 297       if (ThreadingTraits::IsCalledOnValidThread()) {
 298         Cleanup();
 299       } else {
 300         ThreadingTraits::GetSequencedTaskRunner()->PostTask(
 301             FROM_HERE, base::Bind(&ApiResourceData::Cleanup, this));
 302       }
 303     }
 304
 305    private:
 306     friend class base::RefCountedThreadSafe<ApiResourceData>;
 307
 308     virtual ~ApiResourceData() {}
 309
 310     T* GetOwnedResource(const std::string& extension_id, int api_resource_id) {
 311       linked_ptr<T> ptr = api_resource_map_[api_resource_id];
 312       T* resource = ptr.get();
 313       if (resource && extension_id == resource->owner_extension_id())
 314         return resource;
 315       return NULL;
 316     }
 317
 318     base::hash_set<int>* GetOwnedResourceIds(const std::string& extension_id) {
 319       DCHECK(ThreadingTraits::IsCalledOnValidThread());
 320       ExtensionToResourceMap::iterator it =
 321           extension_resource_map_.find(extension_id);
 322       if (it == extension_resource_map_.end())
 323         return NULL;
 324       return &(it->second);
 325     }
 326
 327     void CleanupResourcesFromUnloadedExtension(
 328         const std::string& extension_id) {
 329       CleanupResourcesFromExtension(extension_id, true);
 330     }
 331
 332     void CleanupResourcesFromSuspendedExtension(
 333         const std::string& extension_id) {
 334       CleanupResourcesFromExtension(extension_id, false);
 335     }
 336
 337     void CleanupResourcesFromExtension(const std::string& extension_id,
 338                                        bool remove_all) {
 339       DCHECK(ThreadingTraits::IsCalledOnValidThread());
 340
 341       ExtensionToResourceMap::iterator it =
 342           extension_resource_map_.find(extension_id);
 343       if (it == extension_resource_map_.end())
 344         return;
 345
 346       // Remove all resources, or the non persistent ones only if |remove_all|
 347       // is false.
 348       base::hash_set<int>& resource_ids = it->second;
 349       for (base::hash_set<int>::iterator it = resource_ids.begin();
 350            it != resource_ids.end();) {
 351         bool erase = false;
 352         if (remove_all) {
 353           erase = true;
 354         } else {
 355           linked_ptr<T> ptr = api_resource_map_[*it];
 356           T* resource = ptr.get();
 357           erase = (resource && !resource->IsPersistent());
 358         }
 359
 360         if (erase) {
 361           api_resource_map_.erase(*it);
 362           resource_ids.erase(it++);
 363         } else {
 364           ++it;
 365         }
 366       }  // end for
 367
 368       // Remove extension entry if we removed all its resources.
 369       if (resource_ids.size() == 0) {
 370         extension_resource_map_.erase(extension_id);
 371       }
 372     }
 373
 374     void Cleanup() {
 375       DCHECK(ThreadingTraits::IsCalledOnValidThread());
 376
 377       api_resource_map_.clear();
 378       extension_resource_map_.clear();
 379     }
 380
 381     int GenerateId() { return next_id_++; }
 382
 383     int next_id_;
 384     ApiResourceMap api_resource_map_;
 385     ExtensionToResourceMap extension_resource_map_;
 386   };
 387
 388   content::NotificationRegistrar registrar_;
 389   scoped_refptr<ApiResourceData> data_;
 390
 391   ScopedObserver<ExtensionRegistry, ExtensionRegistryObserver>
 392       extension_registry_observer_;
 393   ScopedObserver<ProcessManager, ProcessManagerObserver>
 394       process_manager_observer_;
 395 };
 396
 397 // With WorkerPoolThreadTraits, ApiResourceManager can be used to manage the
 398 // lifetime of a set of resources that live on sequenced task runner threads
 399 // which ApiFunctions use. Examples of such resources are temporary file
 400 // resources produced by certain API calls.
 401 //
 402 // Instead of kThreadId. classes used for tracking such resources should define
 403 // kSequenceToken and kShutdownBehavior to identify sequence task runner for
 404 // ApiResourceManager to work on and how pending tasks should behave on
 405 // shutdown.
 406 // The user must also define a static const char* service_name() that returns
 407 // the name of the service, and in order for ApiWorkerPoolResourceManager to use
 408 // service_name() friend this class.
 409 //
 410 // In the cc file the user must define a GetFactoryInstance() and manage their
 411 // own instances (typically using LazyInstance or Singleton).
 412 //
 413 // E.g.:
 414 //
 415 // class PoolResource {
 416 //  public:
 417 //   static const char kSequenceToken[] = "temp_files";
 418 //   static const base::SequencedWorkerPool::WorkerShutdown kShutdownBehavior =
 419 //       base::SequencedWorkerPool::BLOCK_SHUTDOWN;
 420 //  private:
 421 //   friend class ApiResourceManager<WorkerPoolResource,
 422 //                                   WorkerPoolThreadTraits>;
 423 //   static const char* service_name() {
 424 //     return "TempFilesResourceManager";
 425 //    }
 426 // };
 427 //
 428 // In the cc file:
 429 //
 430 // static base::LazyInstance<BrowserContextKeyedAPIFactory<
 431 //     ApiResourceManager<Resource, WorkerPoolThreadTraits> > >
 432 //         g_factory = LAZY_INSTANCE_INITIALIZER;
 433 //
 434 //
 435 // template <>
 436 // BrowserContextKeyedAPIFactory<ApiResourceManager<WorkerPoolResource> >*
 437 // ApiResourceManager<WorkerPoolPoolResource,
 438 //                    WorkerPoolThreadTraits>::GetFactoryInstance() {
 439 //   return g_factory.Pointer();
 440 // }
 441 template <typename T>
 442 struct WorkerPoolThreadTraits {
 443   static bool IsCalledOnValidThread() {
 444     return content::BrowserThread::GetBlockingPool()
 445         ->IsRunningSequenceOnCurrentThread(
 446             content::BrowserThread::GetBlockingPool()->GetNamedSequenceToken(
 447                 T::kSequenceToken));
 448   }
 449
 450   static bool IsMessageLoopValid() {
 451     return content::BrowserThread::GetBlockingPool() != NULL;
 452   }
 453
 454   static scoped_refptr<base::SequencedTaskRunner> GetSequencedTaskRunner() {
 455     return content::BrowserThread::GetBlockingPool()
 456         ->GetSequencedTaskRunnerWithShutdownBehavior(
 457             content::BrowserThread::GetBlockingPool()->GetNamedSequenceToken(
 458                 T::kSequenceToken),
 459             T::kShutdownBehavior);
 460   }
 461 };
 462
 463 }  // namespace extensions
 464
 465 #endif  // EXTENSIONS_BROWSER_API_API_RESOURCE_MANAGER_H_