ART: Support trivially-destructible arrays in ArenaUniquePtr
For trivially-destructible types of arrays, we do not have to call
the destructor on all elements. This is minimal support to tag
ownership of some arena-allocated arrays.
Change-Id: I45ec7ed6bab3842c9447d954e359cb8cf047aee6
diff --git a/runtime/base/scoped_arena_containers.h b/runtime/base/scoped_arena_containers.h
index b74aef1..1236585 100644
--- a/runtime/base/scoped_arena_containers.h
+++ b/runtime/base/scoped_arena_containers.h
@@ -20,6 +20,7 @@
#include <deque>
#include <queue>
#include <set>
+#include <type_traits>
#include <unordered_map>
#include <utility>
@@ -218,12 +219,19 @@
}
};
-// Declare but do not define a partial specialization for T[].
-// This is to prevent accidental use of this unsupported use case.
+// In general we lack support for arrays. We would need to call the destructor on each element,
+// which requires access to the array size. Support for that is future work.
+//
+// However, we can support trivially destructible component types, as then a destructor doesn't
+// need to be called.
template <typename T>
class ArenaDelete<T[]> {
public:
- void operator()(T* ptr) const = delete;
+ void operator()(T* ptr ATTRIBUTE_UNUSED) const {
+ static_assert(std::is_trivially_destructible<T>::value,
+ "ArenaUniquePtr does not support non-trivially-destructible arrays.");
+ // TODO: Implement debug checks, and MEMORY_TOOL support.
+ }
};
// Arena unique ptr that only calls the destructor of the element.
