Improvements to Field.get/set.

Avoid unnecessary repeated computation in Field.get/set.
Refactor FromReflectedField and FromReflectedMethod into common helpers in
mirror::ArtField and mirror::ArtMethod, and make use of thereby avoiding
transitions through JNI.
Avoid JNI use from within FromReflectedField and FromReflectedMethod.
Tidy up Field.get/set wrt moving collector support.
Bug: 12189533

Change-Id: I643ab3474bade4abac3a3ae2b6e373b2bb0891c8

1 files changed, 9 insertions, 0 deletions

diff --git a/runtime/mirror/art_field.cc b/runtime/mirror/art_field.cc
index 7740213cf9..f91cab1036 100644
--- a/runtime/mirror/art_field.cc
+++ b/runtime/mirror/art_field.cc
@@ -21,7 +21,9 @@
 #include "object-inl.h"
 #include "object_utils.h"
 #include "runtime.h"
+#include "scoped_thread_state_change.h"
 #include "utils.h"
+#include "well_known_classes.h"
 
 namespace art {
 namespace mirror {
@@ -29,6 +31,13 @@ namespace mirror {
 // TODO: get global references for these
 Class* ArtField::java_lang_reflect_ArtField_ = NULL;
 
+ArtField* ArtField::FromReflectedField(const ScopedObjectAccess& soa, jobject jlr_field) {
+  mirror::ArtField* f = soa.DecodeField(WellKnownClasses::java_lang_reflect_Field_artField);
+  mirror::ArtField* field = f->GetObject(soa.Decode<mirror::Object*>(jlr_field))->AsArtField();
+  DCHECK(field != nullptr);
+  return field;
+}
+
 void ArtField::SetClass(Class* java_lang_reflect_ArtField) {
   CHECK(java_lang_reflect_ArtField_ == NULL);
   CHECK(java_lang_reflect_ArtField != NULL);