Index: third_party/libphonenumber/cpp/src/base/lazy_instance.cc |
=================================================================== |
--- third_party/libphonenumber/cpp/src/base/lazy_instance.cc (revision 0) |
+++ third_party/libphonenumber/cpp/src/base/lazy_instance.cc (revision 0) |
@@ -0,0 +1,44 @@ |
+// Copyright (c) 2010 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/lazy_instance.h" |
+ |
+#include "base/at_exit.h" |
+#include "base/atomicops.h" |
+#include "base/basictypes.h" |
+#include "base/threading/platform_thread.h" |
+#include "base/third_party/dynamic_annotations/dynamic_annotations.h" |
+ |
+namespace base { |
+ |
+bool LazyInstanceHelper::NeedsInstance() { |
+ // Try to create the instance, if we're the first, will go from EMPTY |
+ // to CREATING, otherwise we've already been beaten here. |
+ if (base::subtle::Acquire_CompareAndSwap( |
+ &state_, STATE_EMPTY, STATE_CREATING) == STATE_EMPTY) { |
+ // Caller must create instance |
+ return true; |
+ } else { |
+ // It's either in the process of being created, or already created. Spin. |
+ while (base::subtle::NoBarrier_Load(&state_) != STATE_CREATED) |
+ PlatformThread::YieldCurrentThread(); |
+ } |
+ |
+ // Someone else created the instance. |
+ return false; |
+} |
+ |
+void LazyInstanceHelper::CompleteInstance(void* instance, void (*dtor)(void*)) { |
+ // See the comment to the corresponding HAPPENS_AFTER in Pointer(). |
+ ANNOTATE_HAPPENS_BEFORE(&state_); |
+ |
+ // Instance is created, go from CREATING to CREATED. |
+ base::subtle::Release_Store(&state_, STATE_CREATED); |
+ |
+ // Make sure that the lazily instantiated object will get destroyed at exit. |
+ if (dtor) |
+ base::AtExitManager::RegisterCallback(dtor, instance); |
+} |
+ |
+} // namespace base |
Property changes on: third_party\libphonenumber\cpp\src\base\lazy_instance.cc |
___________________________________________________________________ |
Added: svn:eol-style |
+ LF |