Index: base/task_scheduler/sequence.cc |
diff --git a/base/task_scheduler/sequence.cc b/base/task_scheduler/sequence.cc |
new file mode 100644 |
index 0000000000000000000000000000000000000000..a05c802596ef759a349cb113a6a10171038436af |
--- /dev/null |
+++ b/base/task_scheduler/sequence.cc |
@@ -0,0 +1,79 @@ |
+// Copyright 2016 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/task_scheduler/sequence.h" |
+ |
+#include <utility> |
+ |
+#include "base/logging.h" |
+#include "base/time/time.h" |
+ |
+namespace base { |
+namespace internal { |
+ |
+Sequence::Sequence() = default; |
+ |
+bool Sequence::PushTask(scoped_ptr<Task> task) { |
+ DCHECK(task->sequenced_time.is_null()); |
+ task->sequenced_time = base::TimeTicks::Now(); |
+ |
+ AutoSchedulerLock auto_lock(lock_); |
+ ++num_tasks_per_priority_[static_cast<int>(task->traits.priority())]; |
+ queue_.push(std::move(task)); |
+ |
+ // Return true if the sequence was empty before the push. |
+ return queue_.size() == 1; |
+} |
+ |
+const Task* Sequence::PeekTask() const { |
+ AutoSchedulerLock auto_lock(lock_); |
+ |
+ if (queue_.empty()) |
+ return nullptr; |
+ |
+ return queue_.front().get(); |
+} |
+ |
+bool Sequence::PopTask() { |
+ AutoSchedulerLock auto_lock(lock_); |
+ DCHECK(!queue_.empty()); |
+ |
+ const int priority_index = |
+ static_cast<int>(queue_.front()->traits.priority()); |
+ DCHECK_GT(num_tasks_per_priority_[priority_index], 0U); |
+ --num_tasks_per_priority_[priority_index]; |
+ |
+ queue_.pop(); |
+ return queue_.empty(); |
+} |
+ |
+SequenceSortKey Sequence::GetSortKey() const { |
+ TaskPriority priority = TaskPriority::LOWEST; |
+ base::TimeTicks next_task_sequenced_time; |
+ |
+ { |
+ AutoSchedulerLock auto_lock(lock_); |
+ DCHECK(!queue_.empty()); |
+ |
+ // Find the highest task priority in the sequence. |
+ const int highest_priority_index = static_cast<int>(TaskPriority::HIGHEST); |
+ const int lowest_priority_index = static_cast<int>(TaskPriority::LOWEST); |
+ for (int i = highest_priority_index; i > lowest_priority_index; --i) { |
+ if (num_tasks_per_priority_[i] > 0) { |
+ priority = static_cast<TaskPriority>(i); |
+ break; |
+ } |
+ } |
+ |
+ // Save the sequenced time of the next task in the sequence. |
+ next_task_sequenced_time = queue_.front()->sequenced_time; |
+ } |
+ |
+ return SequenceSortKey(priority, next_task_sequenced_time); |
+} |
+ |
+Sequence::~Sequence() = default; |
+ |
+} // namespace internal |
+} // namespace base |