diff options
8 files changed, 143 insertions, 26 deletions
diff --git a/chrome/browser/sync/glue/browser_thread_model_worker.cc b/chrome/browser/sync/glue/browser_thread_model_worker.cc index 7f4024a..093d282 100644 --- a/chrome/browser/sync/glue/browser_thread_model_worker.cc +++ b/chrome/browser/sync/glue/browser_thread_model_worker.cc @@ -50,7 +50,6 @@ BrowserThreadModelWorker::~BrowserThreadModelWorker() {} void BrowserThreadModelWorker::RegisterForLoopDestruction() { if (BrowserThread::CurrentlyOn(thread_)) { - base::MessageLoop::current()->AddDestructionObserver(this); SetWorkingLoopToCurrent(); } else { BrowserThread::PostTask( diff --git a/chrome/browser/sync/glue/history_model_worker.cc b/chrome/browser/sync/glue/history_model_worker.cc index eb00c92..d9f8754 100644 --- a/chrome/browser/sync/glue/history_model_worker.cc +++ b/chrome/browser/sync/glue/history_model_worker.cc @@ -100,7 +100,6 @@ void HistoryModelWorker::RegisterForLoopDestruction() { } void HistoryModelWorker::RegisterOnDBThread() { - base::MessageLoop::current()->AddDestructionObserver(this); SetWorkingLoopToCurrent(); } diff --git a/chrome/browser/sync/glue/password_model_worker.cc b/chrome/browser/sync/glue/password_model_worker.cc index 6ad5cfd..17ba62e 100644 --- a/chrome/browser/sync/glue/password_model_worker.cc +++ b/chrome/browser/sync/glue/password_model_worker.cc @@ -64,7 +64,6 @@ void PasswordModelWorker::CallDoWorkAndSignalTask( } void PasswordModelWorker::RegisterForPasswordLoopDestruction() { - base::MessageLoop::current()->AddDestructionObserver(this); SetWorkingLoopToCurrent(); } diff --git a/chrome/browser/sync/glue/sync_backend_registrar_unittest.cc b/chrome/browser/sync/glue/sync_backend_registrar_unittest.cc index cd2d29d..7067d99 100644 --- a/chrome/browser/sync/glue/sync_backend_registrar_unittest.cc +++ b/chrome/browser/sync/glue/sync_backend_registrar_unittest.cc @@ -4,6 +4,7 @@ #include "chrome/browser/sync/glue/sync_backend_registrar.h" +#include "base/run_loop.h" #include "chrome/browser/sync/glue/ui_model_worker.h" #include "chrome/test/base/testing_profile.h" #include "components/sync_driver/change_processor_mock.h" @@ -256,6 +257,96 @@ TEST_F(SyncBackendRegistrarTest, ActivateDeactivateNonUIDataType) { TriggerChanges(registrar_.get(), AUTOFILL); } +class SyncBackendRegistrarShutdownTest : public testing::Test { + public: + void BlockDBThread() { + EXPECT_FALSE(db_thread_lock_.Try()); + + db_thread_blocked_.Signal(); + base::AutoLock l(db_thread_lock_); + } + + protected: + friend class TestRegistrar; + + SyncBackendRegistrarShutdownTest() + : thread_bundle_(content::TestBrowserThreadBundle::REAL_DB_THREAD | + content::TestBrowserThreadBundle::REAL_FILE_THREAD | + content::TestBrowserThreadBundle::REAL_IO_THREAD), + db_thread_blocked_(false, false) { + quit_closure_ = run_loop_.QuitClosure(); + } + + virtual ~SyncBackendRegistrarShutdownTest() {} + + void PostQuitOnUIMessageLoop() { + BrowserThread::PostTask(BrowserThread::UI, FROM_HERE, quit_closure_); + } + + content::TestBrowserThreadBundle thread_bundle_; + TestingProfile profile_; + base::WaitableEvent db_thread_blocked_; + base::Lock db_thread_lock_; + base::RunLoop run_loop_; + base::Closure quit_closure_; +}; + +// Wrap SyncBackendRegistrar so that we can monitor its lifetime. +class TestRegistrar : public SyncBackendRegistrar { + public: + explicit TestRegistrar(Profile* profile, + SyncBackendRegistrarShutdownTest* test) + : SyncBackendRegistrar("test", profile, scoped_ptr<base::Thread>()), + test_(test) {} + + ~TestRegistrar() override { test_->PostQuitOnUIMessageLoop(); } + + private: + SyncBackendRegistrarShutdownTest* test_; +}; + +TEST_F(SyncBackendRegistrarShutdownTest, BlockingShutdown) { + // Take ownership of |db_thread_lock_| so that the DB thread can't acquire it. + db_thread_lock_.Acquire(); + + // This will block the DB thread by waiting on |db_thread_lock_|. + BrowserThread::PostTask( + BrowserThread::DB, + FROM_HERE, + base::Bind(&SyncBackendRegistrarShutdownTest::BlockDBThread, + base::Unretained(this))); + + scoped_ptr<TestRegistrar> registrar(new TestRegistrar(&profile_, this)); + base::Thread* sync_thread = registrar->sync_thread(); + + // Stop here until the DB thread gets a chance to run and block on the lock. + // Please note that since the task above didn't finish, the task to + // initialize the worker on the DB thread hasn't had a chance to run yet too. + // Which means ModelSafeWorker::SetWorkingLoopToCurrent hasn't been called + // for the DB worker. + db_thread_blocked_.Wait(); + + registrar->SetInitialTypes(ModelTypeSet()); + + // Start the shutdown. + registrar->RequestWorkerStopOnUIThread(); + + sync_thread->message_loop()->PostTask( + FROM_HERE, + base::Bind(&SyncBackendRegistrar::Shutdown, + base::Unretained(registrar.release()))); + + // The test verifies that the sync thread doesn't block because + // of the blocked DB thread and can finish the shutdown. + sync_thread->message_loop()->RunUntilIdle(); + + db_thread_lock_.Release(); + + // Run the main thread loop until all workers have been removed and the + // registrar destroyed. + run_loop_.Run(); +} + } // namespace } // namespace browser_sync diff --git a/chrome/browser/sync/glue/ui_model_worker.cc b/chrome/browser/sync/glue/ui_model_worker.cc index 2d8bc7d..726deb6 100644 --- a/chrome/browser/sync/glue/ui_model_worker.cc +++ b/chrome/browser/sync/glue/ui_model_worker.cc @@ -47,7 +47,6 @@ UIModelWorker::UIModelWorker(syncer::WorkerLoopDestructionObserver* observer) void UIModelWorker::RegisterForLoopDestruction() { CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI)); - base::MessageLoop::current()->AddDestructionObserver(this); SetWorkingLoopToCurrent(); } 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( diff --git a/sync/internal_api/public/engine/model_safe_worker.h b/sync/internal_api/public/engine/model_safe_worker.h index 03970b9..ad84d49 100644 --- a/sync/internal_api/public/engine/model_safe_worker.h +++ b/sync/internal_api/public/engine/model_safe_worker.h @@ -133,7 +133,13 @@ class SYNC_EXPORT ModelSafeWorker // observation from sync thread when shutting down sync. base::Lock working_loop_lock_; base::MessageLoop* working_loop_; - base::WaitableEvent working_loop_set_wait_; + + // Callback passed with UnregisterForLoopDestruction. Normally this + // remains unset/unused and is stored only if |working_loop_| isn't + // initialized by the time UnregisterForLoopDestruction is called. + // It is safe to copy and thread safe. + // See comments in model_safe_worker.cc for more details. + base::Callback<void(ModelSafeGroup)> unregister_done_callback_; }; // A map that details which ModelSafeGroup each ModelType diff --git a/sync/internal_api/public/engine/passive_model_worker.cc b/sync/internal_api/public/engine/passive_model_worker.cc index 02036d5..3117194 100644 --- a/sync/internal_api/public/engine/passive_model_worker.cc +++ b/sync/internal_api/public/engine/passive_model_worker.cc @@ -18,7 +18,6 @@ PassiveModelWorker::~PassiveModelWorker() { } void PassiveModelWorker::RegisterForLoopDestruction() { - base::MessageLoop::current()->AddDestructionObserver(this); SetWorkingLoopToCurrent(); } |