Delay bookmarks load while the profile is loading.

This CL adds a new DeferredSequencedtaskRunner that queues up tasks
until a first call to Start is issued. It creates such a task runner for the 
execution of bookmarks I/O operations. At profile creation, the bookmarks
task runner is stopped and its execution is started after the profile has
finished loading.

BUG=NONE

Review URL: https://chromiumcodereview.appspot.com/12952005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@194956 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 184 insertions, 0 deletions

diff --git a/base/deferred_sequenced_task_runner_unittest.cc b/base/deferred_sequenced_task_runner_unittest.cc
new file mode 100644
index 0000000..c033ba8
--- /dev/null
+++ b/base/deferred_sequenced_task_runner_unittest.cc
@@ -0,0 +1,184 @@
+// Copyright (c) 2013 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 "base/deferred_sequenced_task_runner.h"
+
+#include "base/basictypes.h"
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/memory/ref_counted.h"
+#include "base/message_loop.h"
+#include "base/message_loop_proxy.h"
+#include "base/threading/non_thread_safe.h"
+#include "base/threading/thread.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+class DeferredSequencedTaskRunnerTest : public testing::Test,
+                                        public base::NonThreadSafe {
+ public:
+  class ExecuteTaskOnDestructor :
+      public base::RefCounted<ExecuteTaskOnDestructor> {
+   public:
+    ExecuteTaskOnDestructor(
+        DeferredSequencedTaskRunnerTest* executor,
+        int task_id)
+        : executor_(executor),
+          task_id_(task_id) {
+    }
+  private:
+    friend class base::RefCounted<ExecuteTaskOnDestructor>;
+    virtual ~ExecuteTaskOnDestructor() {
+      executor_->ExecuteTask(task_id_);
+    }
+    DeferredSequencedTaskRunnerTest* executor_;
+    int task_id_;
+  };
+
+  void ExecuteTask(int task_id) {
+    base::AutoLock lock(lock_);
+    executed_task_ids_.push_back(task_id);
+  }
+
+  void PostExecuteTask(int task_id) {
+    runner_->PostTask(FROM_HERE,
+                      base::Bind(&DeferredSequencedTaskRunnerTest::ExecuteTask,
+                                 base::Unretained(this),
+                                 task_id));
+  }
+
+  void StartRunner() {
+    runner_->Start();
+  }
+
+  void DoNothing(ExecuteTaskOnDestructor* object) {
+  }
+
+ protected:
+  DeferredSequencedTaskRunnerTest() :
+      loop_(),
+      runner_(
+          new base::DeferredSequencedTaskRunner(loop_.message_loop_proxy())) {
+  }
+
+  MessageLoop loop_;
+  scoped_refptr<base::DeferredSequencedTaskRunner> runner_;
+  mutable base::Lock lock_;
+  std::vector<int> executed_task_ids_;
+};
+
+TEST_F(DeferredSequencedTaskRunnerTest, Stopped) {
+  PostExecuteTask(1);
+  loop_.RunUntilIdle();
+  EXPECT_THAT(executed_task_ids_, testing::ElementsAre());
+}
+
+TEST_F(DeferredSequencedTaskRunnerTest, Start) {
+  StartRunner();
+  PostExecuteTask(1);
+  loop_.RunUntilIdle();
+  EXPECT_THAT(executed_task_ids_, testing::ElementsAre(1));
+}
+
+TEST_F(DeferredSequencedTaskRunnerTest, StartWithMultipleElements) {
+  StartRunner();
+  for (int i = 1; i < 5; ++i)
+    PostExecuteTask(i);
+
+  loop_.RunUntilIdle();
+  EXPECT_THAT(executed_task_ids_, testing::ElementsAre(1, 2, 3, 4));
+}
+
+TEST_F(DeferredSequencedTaskRunnerTest, DeferredStart) {
+  PostExecuteTask(1);
+  loop_.RunUntilIdle();
+  EXPECT_THAT(executed_task_ids_, testing::ElementsAre());
+
+  StartRunner();
+  loop_.RunUntilIdle();
+  EXPECT_THAT(executed_task_ids_, testing::ElementsAre(1));
+
+  PostExecuteTask(2);
+  loop_.RunUntilIdle();
+  EXPECT_THAT(executed_task_ids_, testing::ElementsAre(1, 2));
+}
+
+TEST_F(DeferredSequencedTaskRunnerTest, DeferredStartWithMultipleElements) {
+  for (int i = 1; i < 5; ++i)
+    PostExecuteTask(i);
+  loop_.RunUntilIdle();
+  EXPECT_THAT(executed_task_ids_, testing::ElementsAre());
+
+  StartRunner();
+  for (int i = 5; i < 9; ++i)
+    PostExecuteTask(i);
+  loop_.RunUntilIdle();
+  EXPECT_THAT(executed_task_ids_, testing::ElementsAre(1, 2, 3, 4, 5, 6, 7, 8));
+}
+
+TEST_F(DeferredSequencedTaskRunnerTest, DeferredStartWithMultipleThreads) {
+  {
+    base::Thread thread1("DeferredSequencedTaskRunnerTestThread1");
+    base::Thread thread2("DeferredSequencedTaskRunnerTestThread2");
+    thread1.Start();
+    thread2.Start();
+    for (int i = 0; i < 5; ++i) {
+      thread1.message_loop()->PostTask(
+          FROM_HERE,
+          base::Bind(&DeferredSequencedTaskRunnerTest::PostExecuteTask,
+                     base::Unretained(this),
+                     2 * i));
+      thread2.message_loop()->PostTask(
+          FROM_HERE,
+          base::Bind(&DeferredSequencedTaskRunnerTest::PostExecuteTask,
+                     base::Unretained(this),
+                     2 * i + 1));
+      if (i == 2) {
+        thread1.message_loop()->PostTask(
+            FROM_HERE,
+            base::Bind(&DeferredSequencedTaskRunnerTest::StartRunner,
+                       base::Unretained(this)));
+      }
+    }
+  }
+
+  loop_.RunUntilIdle();
+  EXPECT_THAT(executed_task_ids_,
+      testing::WhenSorted(testing::ElementsAre(0, 1, 2, 3, 4, 5, 6, 7, 8, 9)));
+}
+
+TEST_F(DeferredSequencedTaskRunnerTest, ObjectDestructionOrder) {
+  {
+    base::Thread thread("DeferredSequencedTaskRunnerTestThread");
+    thread.Start();
+    runner_ =
+        new base::DeferredSequencedTaskRunner(thread.message_loop_proxy());
+    for (int i = 0; i < 5; ++i) {
+      {
+        // Use a block to ensure that no reference to |short_lived_object|
+        // is kept on the main thread after it is posted to |runner_|.
+        scoped_refptr<ExecuteTaskOnDestructor> short_lived_object =
+            new ExecuteTaskOnDestructor(this, 2 * i);
+        runner_->PostTask(
+            FROM_HERE,
+            base::Bind(&DeferredSequencedTaskRunnerTest::DoNothing,
+                       base::Unretained(this),
+                       short_lived_object));
+      }
+      // |short_lived_object| with id |2 * i| should be destroyed before the
+      // task |2 * i + 1| is executed.
+      PostExecuteTask(2 * i + 1);
+    }
+    StartRunner();
+  }
+
+  // All |short_lived_object| with id |2 * i| are destroyed before the task
+  // |2 * i + 1| is executed.
+  EXPECT_THAT(executed_task_ids_,
+              testing::ElementsAre(0, 1, 2, 3, 4, 5, 6, 7, 8, 9));
+}
+
+}  // namespace