Add GcRoot to clean up and enforce read barriers.
Introduce a value-type wrapper around Object* for GC roots so that 1)
we won't have to directly add the read barrier code in many places and
2) we can avoid accidentally bypassing/missing read barriers on GC
roots (the GcRoot interface ensures that the read barrier is executed
on a read).
The jdwp test passed.
Bug: 12687968
Change-Id: Ib167c7c325b3c7e3900133578815f04d219972a1
diff --git a/runtime/class_linker-inl.h b/runtime/class_linker-inl.h
index 25eb3a3..cf25810 100644
--- a/runtime/class_linker-inl.h
+++ b/runtime/class_linker-inl.h
@@ -18,6 +18,7 @@
#define ART_RUNTIME_CLASS_LINKER_INL_H_
#include "class_linker.h"
+#include "gc_root-inl.h"
#include "gc/heap-inl.h"
#include "mirror/art_field.h"
#include "mirror/class_loader.h"
@@ -40,8 +41,7 @@
inline mirror::Class* ClassLinker::FindArrayClass(Thread* self, mirror::Class** element_class) {
for (size_t i = 0; i < kFindArrayCacheSize; ++i) {
// Read the cached array class once to avoid races with other threads setting it.
- mirror::Class* array_class = ReadBarrier::BarrierForRoot<mirror::Class, kWithReadBarrier>(
- &find_array_class_cache_[i]);
+ mirror::Class* array_class = find_array_class_cache_[i].Read();
if (array_class != nullptr && array_class->GetComponentType() == *element_class) {
return array_class;
}
@@ -54,7 +54,7 @@
mirror::Class* array_class = FindClass(self, descriptor.c_str(), class_loader);
// Benign races in storing array class and incrementing index.
size_t victim_index = find_array_class_cache_next_victim_;
- find_array_class_cache_[victim_index] = array_class;
+ find_array_class_cache_[victim_index] = GcRoot<mirror::Class>(array_class);
find_array_class_cache_next_victim_ = (victim_index + 1) % kFindArrayCacheSize;
return array_class;
}
@@ -204,10 +204,8 @@
inline mirror::Class* ClassLinker::GetClassRoot(ClassRoot class_root)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
- DCHECK(class_roots_ != NULL);
- mirror::ObjectArray<mirror::Class>* class_roots =
- ReadBarrier::BarrierForRoot<mirror::ObjectArray<mirror::Class>, kWithReadBarrier>(
- &class_roots_);
+ DCHECK(!class_roots_.IsNull());
+ mirror::ObjectArray<mirror::Class>* class_roots = class_roots_.Read();
mirror::Class* klass = class_roots->Get(class_root);
DCHECK(klass != NULL);
return klass;
@@ -216,7 +214,7 @@
inline mirror::DexCache* ClassLinker::GetDexCache(size_t idx) {
dex_lock_.AssertSharedHeld(Thread::Current());
DCHECK(idx < dex_caches_.size());
- return ReadBarrier::BarrierForRoot<mirror::DexCache, kWithReadBarrier>(&dex_caches_[idx]);
+ return dex_caches_[idx].Read();
}
} // namespace art