diff options
Diffstat (limited to 'sync/internal_api/public/engine/model_safe_worker.cc')
-rw-r--r-- | sync/internal_api/public/engine/model_safe_worker.cc | 65 |
1 files changed, 45 insertions, 20 deletions
diff --git a/sync/internal_api/public/engine/model_safe_worker.cc b/sync/internal_api/public/engine/model_safe_worker.cc index eb3fc1f..ea8bd4b 100644 --- a/sync/internal_api/public/engine/model_safe_worker.cc +++ b/sync/internal_api/public/engine/model_safe_worker.cc @@ -75,8 +75,8 @@ ModelSafeWorker::ModelSafeWorker(WorkerLoopDestructionObserver* observer) : stopped_(false), work_done_or_stopped_(false, false), observer_(observer), - working_loop_(NULL), - working_loop_set_wait_(true, false) {} + working_loop_(NULL) { +} ModelSafeWorker::~ModelSafeWorker() {} @@ -133,29 +133,54 @@ void ModelSafeWorker::WillDestroyCurrentMessageLoop() { } void ModelSafeWorker::SetWorkingLoopToCurrent() { - base::AutoLock l(working_loop_lock_); - DCHECK(!working_loop_); - working_loop_ = base::MessageLoop::current(); - working_loop_set_wait_.Signal(); -} - -void ModelSafeWorker::UnregisterForLoopDestruction( - base::Callback<void(ModelSafeGroup)> unregister_done_callback) { - // Ok to wait until |working_loop_| is set because this is called on sync - // loop. - working_loop_set_wait_.Wait(); + base::Callback<void(ModelSafeGroup)> unregister_done_callback; { base::AutoLock l(working_loop_lock_); - if (working_loop_ != NULL) { - // Should be called on sync loop. - DCHECK_NE(base::MessageLoop::current(), working_loop_); - working_loop_->PostTask( - FROM_HERE, - base::Bind(&ModelSafeWorker::UnregisterForLoopDestructionAsync, - this, unregister_done_callback)); + DCHECK(!working_loop_); + + if (unregister_done_callback_.is_null()) { + // Expected case - UnregisterForLoopDestruction hasn't been called yet. + base::MessageLoop::current()->AddDestructionObserver(this); + working_loop_ = base::MessageLoop::current(); + } else { + // Rare case which is possible when the model type thread remains + // blocked for the entire session and UnregisterForLoopDestruction ends + // up being called before this method. This method is posted unlike + // UnregisterForLoopDestruction - that's why they can end up being called + // out of order. + // In this case we skip the destruction observer registration + // and just invoke the callback stored at UnregisterForLoopDestruction. + DCHECK(stopped_); + unregister_done_callback = unregister_done_callback_; + unregister_done_callback_.Reset(); } } + + if (!unregister_done_callback.is_null()) { + unregister_done_callback.Run(GetModelSafeGroup()); + } +} + +void ModelSafeWorker::UnregisterForLoopDestruction( + base::Callback<void(ModelSafeGroup)> unregister_done_callback) { + base::AutoLock l(working_loop_lock_); + if (working_loop_ != NULL) { + // Normal case - observer registration has been already done. + // Delegate to the sync thread to do the actual unregistration in + // UnregisterForLoopDestructionAsync. + DCHECK_NE(base::MessageLoop::current(), working_loop_); + working_loop_->PostTask( + FROM_HERE, + base::Bind(&ModelSafeWorker::UnregisterForLoopDestructionAsync, + this, + unregister_done_callback)); + } else { + // The working loop is still unknown, probably because the model type + // thread is blocked. Store the callback to be called from + // SetWorkingLoopToCurrent. + unregister_done_callback_ = unregister_done_callback; + } } void ModelSafeWorker::UnregisterForLoopDestructionAsync( |