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-rw-r--r--base/lazy_instance.h11
1 files changed, 10 insertions, 1 deletions
diff --git a/base/lazy_instance.h b/base/lazy_instance.h
index ebf1e73..f8d5987 100644
--- a/base/lazy_instance.h
+++ b/base/lazy_instance.h
@@ -36,14 +36,19 @@
#define BASE_LAZY_INSTANCE_H_
#pragma once
+#include <new> // For placement new.
+
#include "base/atomicops.h"
#include "base/basictypes.h"
#include "base/third_party/dynamic_annotations/dynamic_annotations.h"
+#include "base/thread_restrictions.h"
namespace base {
template <typename Type>
struct DefaultLazyInstanceTraits {
+ static const bool kAllowedToAccessOnNonjoinableThread = false;
+
static Type* New(void* instance) {
// Use placement new to initialize our instance in our preallocated space.
// The parenthesis is very important here to force POD type initialization.
@@ -57,6 +62,8 @@ struct DefaultLazyInstanceTraits {
template <typename Type>
struct LeakyLazyInstanceTraits {
+ static const bool kAllowedToAccessOnNonjoinableThread = true;
+
static Type* New(void* instance) {
return DefaultLazyInstanceTraits<Type>::New(instance);
}
@@ -112,6 +119,9 @@ class LazyInstance : public LazyInstanceHelper {
}
Type* Pointer() {
+ if (!Traits::kAllowedToAccessOnNonjoinableThread)
+ base::ThreadRestrictions::AssertSingletonAllowed();
+
// We will hopefully have fast access when the instance is already created.
if ((base::subtle::NoBarrier_Load(&state_) != STATE_CREATED) &&
NeedsInstance()) {
@@ -126,7 +136,6 @@ class LazyInstance : public LazyInstanceHelper {
// and CompleteInstance(...) happens before "return instance_" below.
// See the corresponding HAPPENS_BEFORE in CompleteInstance(...).
ANNOTATE_HAPPENS_AFTER(&state_);
-
return instance_;
}