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authorBen Murdoch <benm@google.com>2010-07-29 17:14:53 +0100
committerBen Murdoch <benm@google.com>2010-08-04 14:29:45 +0100
commitc407dc5cd9bdc5668497f21b26b09d988ab439de (patch)
tree7eaf8707c0309516bdb042ad976feedaf72b0bb1 /base/lazy_instance.cc
parent0998b1cdac5733f299c12d88bc31ef9c8035b8fa (diff)
downloadexternal_chromium-c407dc5cd9bdc5668497f21b26b09d988ab439de.zip
external_chromium-c407dc5cd9bdc5668497f21b26b09d988ab439de.tar.gz
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Merge Chromium src@r53293
Change-Id: Ia79acf8670f385cee48c45b0a75371d8e950af34
Diffstat (limited to 'base/lazy_instance.cc')
-rw-r--r--base/lazy_instance.cc45
1 files changed, 24 insertions, 21 deletions
diff --git a/base/lazy_instance.cc b/base/lazy_instance.cc
index 9923253..f98ba3f 100644
--- a/base/lazy_instance.cc
+++ b/base/lazy_instance.cc
@@ -6,41 +6,44 @@
#include "base/at_exit.h"
#include "base/atomicops.h"
-#include "base/dynamic_annotations.h"
#include "base/basictypes.h"
#include "base/platform_thread.h"
+#include "base/third_party/dynamic_annotations/dynamic_annotations.h"
namespace base {
-void LazyInstanceHelper::EnsureInstance(void* instance,
- void (*ctor)(void*),
- void (*dtor)(void*)) {
+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) {
- // Created the instance in the space provided by |instance|.
- ctor(instance);
-
- // 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);
-
- // Allow reusing the LazyInstance (reset it to the initial state). This
- // makes possible calling all AtExit callbacks between tests. Assumes that
- // no other threads execute when AtExit callbacks are processed.
- base::AtExitManager::RegisterCallback(&LazyInstanceHelper::ResetState,
- this);
-
- // Make sure that the lazily instantiated object will get destroyed at exit.
- base::AtExitManager::RegisterCallback(dtor, instance);
+ // 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);
+
+ // Allow reusing the LazyInstance (reset it to the initial state). This
+ // makes possible calling all AtExit callbacks between tests. Assumes that
+ // no other threads execute when AtExit callbacks are processed.
+ base::AtExitManager::RegisterCallback(&LazyInstanceHelper::ResetState,
+ this);
+
+ // Make sure that the lazily instantiated object will get destroyed at exit.
+ base::AtExitManager::RegisterCallback(dtor, instance);
}
// static