[SyncFS] Post tasks between SyncEngine and SyncWorker

chrome/browser/sync_file_system/drive_backend/sync_worker.cc

Index: chrome/browser/sync_file_system/drive_backend/sync_worker.cc
diff --git a/chrome/browser/sync_file_system/drive_backend/sync_worker.cc b/chrome/browser/sync_file_system/drive_backend/sync_worker.cc
index f58c66c3f83b268e4f5dfd2fb23dea0744b4bd74..260c6e4aa0d6373c573f064a6014c3406da388eb 100644
--- a/chrome/browser/sync_file_system/drive_backend/sync_worker.cc
+++ b/chrome/browser/sync_file_system/drive_backend/sync_worker.cc
@@ -56,6 +56,30 @@ namespace {
 
 void EmptyStatusCallback(SyncStatusCode status) {}
 
+template <typename T>
+void RelayToTaskRunner(
+    base::TaskRunner* task_runner,
+    const tracked_objects::Location& from_here,
+    const base::Callback<void(T)>& callback,
+    typename base::internal::CallbackParamTraits<T>::ForwardType& p1) {
+  task_runner->PostTask(from_here,
+                        base::Bind(callback,
+                                   base::internal::CallbackForward(p1)));
+}
+
+template <typename T1, typename T2>
+void RelayToTaskRunner(
+    base::TaskRunner* task_runner,
+    const tracked_objects::Location& from_here,
+    const base::Callback<void(T1, T2)>& callback,
+    const T1& p1,
+    typename base::internal::CallbackParamTraits<T2>::ForwardType& p2) {
+  task_runner->PostTask(from_here,
+                        base::Bind(callback,
+                                   p1,
+                                   base::internal::CallbackForward(p2)));
+}
+
 }  // namespace
 
 scoped_ptr<SyncWorker> SyncWorker::CreateOnWorker(
@@ -99,7 +123,8 @@ void SyncWorker::RegisterOrigin(
   scoped_ptr<RegisterAppTask> task(
       new RegisterAppTask(context_.get(), origin.host()));
   if (task->CanFinishImmediately()) {
-    callback.Run(SYNC_STATUS_OK);
+    RelayToTaskRunner(context_->GetBlockingTaskRunner(),
+                      FROM_HERE, callback, SYNC_STATUS_OK);

[tzik, 2014/04/17 17:48:32]

All existing RelayToTaskRunner usage in this file can be replaced with PostTask.

GetBlockingTaskRunner() looks not the right place to post the callback from
here.
Could you directly post it to GetUiTaskRunner()?

[peria, 2014/04/18 05:19:36]

Done.
I may have misunderstood the usage of RelayToTaskRunner.
I remove all RelayToTaskRunner in this CL, and add it again in another CL.

     return;
   }
 
@@ -211,8 +236,9 @@ void SyncWorker::SetSyncEnabled(bool enabled) {
   if (old_state == GetCurrentState())
     return;
 
-  // TODO(peria): PostTask()
-  sync_engine_->UpdateSyncEnabled(enabled);
+  context_->GetUiTaskRunner()->PostTask(
+      FROM_HERE,
+      base::Bind(&SyncEngine::UpdateSyncEnabled, sync_engine_, enabled));
 }
 
 SyncStatusCode SyncWorker::SetDefaultConflictResolutionPolicy(
@@ -274,8 +300,9 @@ void SyncWorker::NotifyLastOperationStatus(
   UpdateServiceStateFromSyncStatusCode(status, used_network);
 
   if (GetMetadataDatabase()) {
-    // TODO(peria): Post task
-    sync_engine_->NotifyLastOperationStatus();
+    context_->GetUiTaskRunner()->PostTask(
+        FROM_HERE,
+        base::Bind(&SyncEngine::NotifyLastOperationStatus, sync_engine_));
   }
 }
 
@@ -360,18 +387,22 @@ SyncWorker::SyncWorker(
 
 void SyncWorker::DoDisableApp(const std::string& app_id,
                               const SyncStatusCallback& callback) {
-  if (GetMetadataDatabase())
+  if (GetMetadataDatabase()) {
     GetMetadataDatabase()->DisableApp(app_id, callback);
-  else
-    callback.Run(SYNC_STATUS_OK);
+  } else {
+    RelayToTaskRunner(context_->GetBlockingTaskRunner(),
+                      FROM_HERE, callback, SYNC_STATUS_OK);
+  }
 }
 
 void SyncWorker::DoEnableApp(const std::string& app_id,
                              const SyncStatusCallback& callback) {
-  if (GetMetadataDatabase())
+  if (GetMetadataDatabase()) {
     GetMetadataDatabase()->EnableApp(app_id, callback);
-  else
-    callback.Run(SYNC_STATUS_OK);
+  } else {
+    RelayToTaskRunner(context_->GetBlockingTaskRunner(),
+                      FROM_HERE, callback, SYNC_STATUS_OK);
+  }
 }
 
 void SyncWorker::PostInitializeTask() {
@@ -410,8 +441,9 @@ void SyncWorker::DidInitialize(SyncEngineInitializer* initializer,
   if (metadata_database)
     context_->SetMetadataDatabase(metadata_database.Pass());
 
-  // TODO(peria): Post task
-  sync_engine_->UpdateRegisteredApps();
+  context_->GetUiTaskRunner()->PostTask(
+      FROM_HERE,
+      base::Bind(&SyncEngine::UpdateRegisteredApps, sync_engine_));
 }
 
 void SyncWorker::DidProcessRemoteChange(RemoteToLocalSyncer* syncer,
@@ -420,13 +452,18 @@ void SyncWorker::DidProcessRemoteChange(RemoteToLocalSyncer* syncer,
   if (syncer->is_sync_root_deletion()) {
     MetadataDatabase::ClearDatabase(context_->PassMetadataDatabase());
     PostInitializeTask();
-    callback.Run(status, syncer->url());
+    RelayToTaskRunner(context_->GetUiTaskRunner(),
+                      FROM_HERE,
+                      callback,
+                      status,
+                      syncer->url());
     return;
   }
 
   if (status == SYNC_STATUS_OK) {
-    // TODO(peria): Post task
-    sync_engine_->DidProcessRemoteChange(syncer);
+    context_->GetUiTaskRunner()->PostTask(
+        FROM_HERE,
+        base::Bind(&SyncEngine::DidProcessRemoteChange, sync_engine_, syncer));
 
     if (syncer->sync_action() == SYNC_ACTION_DELETED &&
         syncer->url().is_valid() &&
@@ -435,13 +472,18 @@ void SyncWorker::DidProcessRemoteChange(RemoteToLocalSyncer* syncer,
     }
     should_check_conflict_ = true;
   }
-  callback.Run(status, syncer->url());
+
+  RelayToTaskRunner(context_->GetUiTaskRunner(),
+                    FROM_HERE,
+                    callback,
+                    status,
+                    syncer->url());
 }
 
 void SyncWorker::DidApplyLocalChange(LocalToRemoteSyncer* syncer,
                                      const SyncStatusCallback& callback,
                                      SyncStatusCode status) {
-  // TODO(peria): Post task
+  // TODO(peria): PostTask (Simple replace fails DriveBackendSync* tests)
   sync_engine_->DidApplyLocalChange(syncer, status);
 
   if (status == SYNC_STATUS_UNKNOWN_ORIGIN && syncer->url().is_valid()) {
@@ -464,16 +506,11 @@ void SyncWorker::DidApplyLocalChange(LocalToRemoteSyncer* syncer,
         base::TimeDelta::FromSeconds(kListChangesRetryDelaySeconds);
   }
 
-  if (status != SYNC_STATUS_OK &&
-      status != SYNC_STATUS_NO_CHANGE_TO_SYNC) {
-    callback.Run(status);
-    return;
-  }
-
   if (status == SYNC_STATUS_OK)
     should_check_conflict_ = true;
 
-  callback.Run(status);
+  RelayToTaskRunner(context_->GetBlockingTaskRunner(),
+                    FROM_HERE, callback, status);
 }
 
 void SyncWorker::MaybeStartFetchChanges() {
@@ -583,8 +620,10 @@ void SyncWorker::UpdateServiceState(RemoteServiceState state,
   util::Log(logging::LOG_VERBOSE, FROM_HERE,
             "Service state changed: %d->%d: %s",
             old_state, GetCurrentState(), description.c_str());
-  // TODO(peria): Post task
-  sync_engine_->UpdateServiceState(description);
+
+  context_->GetUiTaskRunner()->PostTask(
+      FROM_HERE,
+      base::Bind(&SyncEngine::UpdateServiceState, sync_engine_, description));
 }
 
 }  // namespace drive_backend