commit 94f7b49578b6aaa80de8ffed230648d601393905
author Hiroshi Yamauchi <yamauchi@google.com> Tue Jul 22 18:08:23 2014 -0700
committer Hiroshi Yamauchi <yamauchi@google.com> Tue Jul 29 13:30:46 2014 -0700
tree cfc69e453faefee38178ceb85378e1f0f1e17812
parent 8df73882c60451e7f789bf9b1f3db2d7dc228640

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

runtime/mirror/art_field.cc

diff --git a/runtime/mirror/art_field.cc b/runtime/mirror/art_field.cc
index da21dfe..3c7c6ce 100644
--- a/runtime/mirror/art_field.cc
+++ b/runtime/mirror/art_field.cc
@@ -29,7 +29,7 @@
 namespace mirror {
 
 // TODO: Get global references for these
-Class* ArtField::java_lang_reflect_ArtField_ = NULL;
+GcRoot<Class> ArtField::java_lang_reflect_ArtField_;
 
 ArtField* ArtField::FromReflectedField(const ScopedObjectAccessAlreadyRunnable& soa,
                                        jobject jlr_field) {
@@ -40,14 +40,14 @@
 }
 
 void ArtField::SetClass(Class* java_lang_reflect_ArtField) {
-  CHECK(java_lang_reflect_ArtField_ == NULL);
+  CHECK(java_lang_reflect_ArtField_.IsNull());
   CHECK(java_lang_reflect_ArtField != NULL);
-  java_lang_reflect_ArtField_ = java_lang_reflect_ArtField;
+  java_lang_reflect_ArtField_ = GcRoot<Class>(java_lang_reflect_ArtField);
 }
 
 void ArtField::ResetClass() {
-  CHECK(java_lang_reflect_ArtField_ != NULL);
-  java_lang_reflect_ArtField_ = NULL;
+  CHECK(!java_lang_reflect_ArtField_.IsNull());
+  java_lang_reflect_ArtField_ = GcRoot<Class>(nullptr);
 }
 
 void ArtField::SetOffset(MemberOffset num_bytes) {
@@ -64,9 +64,8 @@
 }
 
 void ArtField::VisitRoots(RootCallback* callback, void* arg) {
-  if (java_lang_reflect_ArtField_ != nullptr) {
-    callback(reinterpret_cast<mirror::Object**>(&java_lang_reflect_ArtField_), arg, 0,
-             kRootStickyClass);
+  if (!java_lang_reflect_ArtField_.IsNull()) {
+    java_lang_reflect_ArtField_.VisitRoot(callback, arg, 0, kRootStickyClass);
   }
 }