DomStorage commit task sequencing.

webkit/dom_storage/dom_storage_task_runner.cc

 // Copyright (c) 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.
 
 #include "webkit/dom_storage/dom_storage_task_runner.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/message_loop_proxy.h"
 #include "base/tracked_objects.h"
@@ skipping 46 matching lines @@
 
 // DomStorageWorkerPoolTaskRunner
 
 DomStorageWorkerPoolTaskRunner::DomStorageWorkerPoolTaskRunner(
     base::SequencedWorkerPool* sequenced_worker_pool,
     base::SequencedWorkerPool::SequenceToken sequence_token,
     base::MessageLoopProxy* delayed_task_loop)
     : DomStorageTaskRunner(delayed_task_loop),
       sequenced_worker_pool_(sequenced_worker_pool),
       sequence_token_(sequence_token) {
+
+  // TODO: have ctor argument for this
+  commit_sequence_token_ =
+      sequenced_worker_pool->GetNamedSequenceToken("dom_storage_commit");
 }
 
 DomStorageWorkerPoolTaskRunner::~DomStorageWorkerPoolTaskRunner() {
 }
 
 bool DomStorageWorkerPoolTaskRunner::PostDelayedTask(
     const tracked_objects::Location& from_here,
     const base::Closure& task,
     base::TimeDelta delay) {
   // Note base::TaskRunner implements PostTask in terms of PostDelayedTask
   // with a delay of zero, we detect that usage and avoid the unecessary
   // trip thru the message_loop.
   if (delay == base::TimeDelta()) {
-    // We can skip on shutdown as the destructor of DomStorageArea will ensure
-    // that any remaining data is committed to disk.
+    // Nominally, tasks are posted that can be skipped during shutdown.
     return sequenced_worker_pool_->PostSequencedWorkerTaskWithShutdownBehavior(
         sequence_token_, from_here, task,
         base::SequencedWorkerPool::SKIP_ON_SHUTDOWN);
   }
   // Post a task to call this->PostTask() after the delay.
   return message_loop_->PostDelayedTask(
       FROM_HERE,
       base::Bind(base::IgnoreResult(&DomStorageWorkerPoolTaskRunner::PostTask),
                  this, from_here, task),
       delay);
 }
 
-// MockDomStorageTaskRunner
+bool DomStorageWorkerPoolTaskRunner::PostShutdownBlockingTask(

[benm (inactive), 2012/03/19 14:22:53]

Maybe rather than having two methods have one that takes an enum parameter for
which sequence to post to?

[michaeln, 2012/03/19 16:04:42]

sgtm... PostShutdownBlockingTask(sequence_id, ...)

+      const tracked_objects::Location& from_here,
+      const base::Closure& task) {
+  return sequenced_worker_pool_->PostSequencedWorkerTaskWithShutdownBehavior(
+      sequence_token_, from_here, task,
+      base::SequencedWorkerPool::BLOCK_SHUTDOWN);
+}
+
+bool DomStorageWorkerPoolTaskRunner::PostShutdownBlockingCommitTask(
+      const tracked_objects::Location& from_here,
+      const base::Closure& task) {
+  return sequenced_worker_pool_->PostSequencedWorkerTaskWithShutdownBehavior(
+      commit_sequence_token_, from_here, task,
+      base::SequencedWorkerPool::BLOCK_SHUTDOWN);
+}
+
+// MockDomStorageTaskRunner, there is no distinction between
+// shutdown blocking or the commit sequence vs the read sequence
+// in our mock, all tasks are scheduled on the provided message
+// loop. And delay values are all squashed to zero.
 
 MockDomStorageTaskRunner::MockDomStorageTaskRunner(
     base::MessageLoopProxy* message_loop)
     : DomStorageTaskRunner(message_loop) {
 }
 
 bool MockDomStorageTaskRunner::PostDelayedTask(
     const tracked_objects::Location& from_here,
     const base::Closure& task,
     base::TimeDelta delay) {
-  // Squash all delays to zero in our mock.
   return DomStorageTaskRunner::PostDelayedTask(
       from_here, task, base::TimeDelta());
 }
 
+bool MockDomStorageTaskRunner::PostShutdownBlockingTask(
+      const tracked_objects::Location& from_here,
+      const base::Closure& task) {
+  return PostTask(from_here, task);
+}
+
+bool MockDomStorageTaskRunner::PostShutdownBlockingCommitTask(
+      const tracked_objects::Location& from_here,
+      const base::Closure& task) {
+  return PostTask(from_here, task);
+}
+
 }  // namespace dom_storage