Retry: sync: Gracefully handle early shutdown

sync/internal_api/public/sync_manager.h

 // Copyright 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 SYNC_INTERNAL_API_PUBLIC_SYNC_MANAGER_H_
 #define SYNC_INTERNAL_API_PUBLIC_SYNC_MANAGER_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 27 matching lines @@
 class Encryptor;
 struct Experiments;
 class ExtensionsActivity;
 class HttpPostProviderFactory;
 class InternalComponentsFactory;
 class JsBackend;
 class JsEventHandler;
 class SyncEncryptionHandler;
 class SyncScheduler;
 struct UserShare;
+class CancelationSignal;
 
 namespace sessions {
 class SyncSessionSnapshot;
 }  // namespace sessions
 
 // Used by SyncManager::OnConnectionStatusChange().
 enum ConnectionStatus {
   CONNECTION_OK,
   CONNECTION_AUTH_ERROR,
   CONNECTION_SERVER_ERROR
@@ skipping 234 matching lines @@
   // |user_agent| is a 7-bit ASCII string suitable for use as the User-Agent
   // HTTP header. Used internally when collecting stats to classify clients.
   // |invalidator| is owned and used to listen for invalidations.
   // |invalidator_client_id| is used to unqiuely identify this client to the
   // invalidation notification server.
   // |restored_key_for_bootstrapping| is the key used to boostrap the
   // cryptographer
   // |keystore_encryption_enabled| determines whether we enable the keystore
   // encryption functionality in the cryptographer/nigori.
   // |report_unrecoverable_error_function| may be NULL.
+  // |cancelation_signal| carries shutdown requests across threads.  This one
+  // will be used to cut short any network I/O and tell the syncer to exit
+  // early.
   //
   // TODO(akalin): Replace the |post_factory| parameter with a
   // URLFetcher parameter.
   virtual void Init(
       const base::FilePath& database_location,
       const WeakHandle<JsEventHandler>& event_handler,
       const std::string& sync_server_and_path,
       int sync_server_port,
       bool use_ssl,
       scoped_ptr<HttpPostProviderFactory> post_factory,
       const std::vector<ModelSafeWorker*>& workers,
       ExtensionsActivity* extensions_activity,
       ChangeDelegate* change_delegate,
       const SyncCredentials& credentials,
       const std::string& invalidator_client_id,
       const std::string& restored_key_for_bootstrapping,
       const std::string& restored_keystore_key_for_bootstrapping,
       InternalComponentsFactory* internal_components_factory,
       Encryptor* encryptor,
       scoped_ptr<UnrecoverableErrorHandler> unrecoverable_error_handler,
       ReportUnrecoverableErrorFunction report_unrecoverable_error_function,
-      bool use_oauth2_token) = 0;
+      bool use_oauth2_token,
+      CancelationSignal* cancelation_signal) = 0;
 
   // Throw an unrecoverable error from a transaction (mostly used for
   // testing).
   virtual void ThrowUnrecoverableError() = 0;
 
   virtual ModelTypeSet InitialSyncEndedTypes() = 0;
 
   // Returns those types within |types| that have an empty progress marker
   // token.
   virtual ModelTypeSet GetTypesWithEmptyProgressMarkerToken(
@@ skipping 51 matching lines @@
   // potentially dereference garbage.
   virtual void RemoveObserver(Observer* observer) = 0;
 
   // Status-related getter.  May be called on any thread.
   virtual SyncStatus GetDetailedStatus() const = 0;
 
   // Call periodically from a database-safe thread to persist recent changes
   // to the syncapi model.
   virtual void SaveChanges() = 0;
 
-  // Initiates shutdown of various components in the sync engine.  Must be
-  // called from the main thread to allow preempting ongoing tasks on the sync
-  // loop (that may be blocked on I/O).  The semantics of |callback| are the
-  // same as with StartConfigurationMode. If provided and a scheduler / sync
-  // loop exists, it will be invoked from the sync loop by the scheduler to
-  // notify that all work has been flushed + cancelled, and it is idle.
-  // If no scheduler exists, the callback is run immediately (from the loop
-  // this was created on, which is the sync loop), as sync is effectively
-  // stopped.
-  virtual void StopSyncingForShutdown() = 0;
-
   // Issue a final SaveChanges, and close sqlite handles.
   virtual void ShutdownOnSyncThread() = 0;
 
   // May be called from any thread.
   virtual UserShare* GetUserShare() = 0;
 
   // Returns the cache_guid of the currently open database.
   // Requires that the SyncManager be initialized.
   virtual const std::string cache_guid() = 0;
 
   // Reads the nigori node to determine if any experimental features should
   // be enabled.
   // Note: opens a transaction.  May be called on any thread.
   virtual bool ReceivedExperiment(Experiments* experiments) = 0;
 
   // Uses a read-only transaction to determine if the directory being synced has
   // any remaining unsynced items.  May be called on any thread.
   virtual bool HasUnsyncedItems() = 0;
 
   // Returns the SyncManager's encryption handler.
   virtual SyncEncryptionHandler* GetEncryptionHandler() = 0;
 
   // Ask the SyncManager to fetch updates for the given types.
   virtual void RefreshTypes(ModelTypeSet types) = 0;
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_INTERNAL_API_PUBLIC_SYNC_MANAGER_H_