Index: base/task_scheduler/shutdown_manager.cc |
diff --git a/base/task_scheduler/shutdown_manager.cc b/base/task_scheduler/shutdown_manager.cc |
new file mode 100644 |
index 0000000000000000000000000000000000000000..35842f5148d9a3597018c3f9b81c536c718ae859 |
--- /dev/null |
+++ b/base/task_scheduler/shutdown_manager.cc |
@@ -0,0 +1,100 @@ |
+// 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/shutdown_manager.h" |
+ |
+#include "base/atomicops.h" |
+ |
+namespace base { |
+namespace internal { |
+ |
+ShutdownManager::ShutdownManager() |
+ : cv_(lock_.CreateConditionVariable()), |
+ num_tasks_blocking_shutdown_(0), |
+ is_shutting_down_(false), |
+ shutdown_completed_(false) {} |
+ |
+ShutdownManager::~ShutdownManager() = default; |
+ |
+void ShutdownManager::Shutdown() { |
+ AutoSchedulerLock auto_lock(lock_); |
+ |
+ DCHECK(!is_shutting_down_) << "ShutdownManager::Shutdown can't be called " |
+ "simultaneously on multiple threads."; |
gab
2016/02/23 22:28:22
How about (as mentioned in header):
DCHECK(!shutd
fdoray
2016/02/26 15:53:28
Done.
|
+ is_shutting_down_ = true; |
+ |
+ // Wait until the number of tasks blocking shutdown is zero. |
+ while (num_tasks_blocking_shutdown_ != 0) |
+ cv_->Wait(); |
+ |
+ is_shutting_down_ = false; |
+ shutdown_completed_ = true; |
+} |
+ |
+bool ShutdownManager::ShouldPostTask(TaskShutdownBehavior shutdown_behavior) { |
+ AutoSchedulerLock auto_lock(lock_); |
gab
2016/02/23 22:28:23
Please highlight in CL description that you have a
fdoray
2016/02/26 15:53:28
Done.
|
+ |
+ if (shutdown_completed_) |
+ return false; |
+ |
+ if (shutdown_behavior == TaskShutdownBehavior::BLOCK_SHUTDOWN) { |
+ ++num_tasks_blocking_shutdown_; |
+ return true; |
+ } |
+ |
+ return !is_shutting_down_; |
+} |
+ |
+bool ShutdownManager::ShouldScheduleTask( |
+ TaskShutdownBehavior shutdown_behavior) { |
+ AutoSchedulerLock auto_lock(lock_); |
+ |
+ if (shutdown_completed_) |
+ return false; |
+ |
+ switch (shutdown_behavior) { |
+ case TaskShutdownBehavior::BLOCK_SHUTDOWN: { |
robliao
2016/02/24 01:22:44
Nit: We generally don't use braces for switch stat
fdoray
2016/02/26 15:53:28
Done.
|
+ return true; |
+ } |
+ |
+ case TaskShutdownBehavior::SKIP_ON_SHUTDOWN: { |
+ if (is_shutting_down_) |
+ return false; |
+ ++num_tasks_blocking_shutdown_; |
+ return true; |
+ } |
+ |
+ case TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN: { |
+ return !is_shutting_down_; |
+ } |
+ } |
+} |
+ |
+void ShutdownManager::DidExecuteTask(TaskShutdownBehavior shutdown_behavior) { |
+ if (shutdown_behavior == TaskShutdownBehavior::BLOCK_SHUTDOWN || |
+ shutdown_behavior == TaskShutdownBehavior::SKIP_ON_SHUTDOWN) { |
+ AutoSchedulerLock auto_lock(lock_); |
+ --num_tasks_blocking_shutdown_; |
+ if (num_tasks_blocking_shutdown_ == 0) |
+ cv_->Signal(); |
+ } |
+} |
+ |
+void ShutdownManager::set_is_shutting_down_for_testing(bool is_shutting_down) { |
+ is_shutting_down_ = is_shutting_down; |
+ subtle::MemoryBarrier(); |
+} |
+ |
+bool ShutdownManager::is_shutting_down_for_testing() const { |
+ subtle::MemoryBarrier(); |
gab
2016/02/23 22:28:23
Locking seems fine in test code (at least for now)
fdoray
2016/02/26 15:53:28
Done.
|
+ return is_shutting_down_; |
+} |
+ |
+bool ShutdownManager::shutdown_completed() const { |
+ subtle::MemoryBarrier(); |
gab
2016/02/23 22:28:22
I'd say use a lock here for now (until you come up
fdoray
2016/02/26 15:53:28
Done.
|
+ return shutdown_completed_; |
+} |
+ |
+} // namespace internal |
+} // namespace base |