Move ArtField to native

Add linear alloc. Moved ArtField to be native object. Changed image
writer to put ArtFields after the mirror section.

Savings:
2MB on low ram devices
4MB on normal devices

Total PSS measurements before (normal N5, 95s after shell start):
Image size: 7729152 bytes
23112 kB: .NonMoving
23212 kB: .NonMoving
22868 kB: .NonMoving
23072 kB: .NonMoving
22836 kB: .NonMoving
19618 kB: .Zygote
19850 kB: .Zygote
19623 kB: .Zygote
19924 kB: .Zygote
19612 kB: .Zygote
Avg: 42745.4 kB

After:
Image size: 7462912 bytes
17440 kB: .NonMoving
16776 kB: .NonMoving
16804 kB: .NonMoving
17812 kB: .NonMoving
16820 kB: .NonMoving
18788 kB: .Zygote
18856 kB: .Zygote
19064 kB: .Zygote
18841 kB: .Zygote
18629 kB: .Zygote
3499 kB: .LinearAlloc
3408 kB: .LinearAlloc
3424 kB: .LinearAlloc
3600 kB: .LinearAlloc
3436 kB: .LinearAlloc
Avg: 39439.4 kB

No reflection performance changes.

Bug: 19264997
Bug: 17643507

Change-Id: I10c73a37913332080aeb978c7c94713bdfe4fe1c

1 files changed, 53 insertions, 32 deletions

diff --git a/runtime/mirror/class.h b/runtime/mirror/class.h
index b82a58f4c2..92493bc567 100644
--- a/runtime/mirror/class.h
+++ b/runtime/mirror/class.h
@@ -35,6 +35,7 @@
 
 namespace art {
 
+class ArtField;
 struct ClassOffsets;
 template<class T> class Handle;
 template<class T> class Handle;
@@ -44,7 +45,6 @@ template<size_t kNumReferences> class PACKED(4) StackHandleScope;
 
 namespace mirror {
 
-class ArtField;
 class ArtMethod;
 class ClassLoader;
 class DexCache;
@@ -420,9 +420,6 @@ class MANAGED Class FINAL : public Object {
   bool IsThrowableClass() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
   template<ReadBarrierOption kReadBarrierOption = kWithReadBarrier>
-  bool IsArtFieldClass() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
-
-  template<ReadBarrierOption kReadBarrierOption = kWithReadBarrier>
   bool IsArtMethodClass() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
   template<ReadBarrierOption kReadBarrierOption = kWithReadBarrier>
@@ -823,17 +820,22 @@ class MANAGED Class FINAL : public Object {
   ALWAYS_INLINE void SetIfTable(IfTable* new_iftable) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
   // Get instance fields of the class (See also GetSFields).
-  ObjectArray<ArtField>* GetIFields() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+  ArtField* GetIFields() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-  void SetIFields(ObjectArray<ArtField>* new_ifields) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+  void SetIFields(ArtField* new_ifields) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-  uint32_t NumInstanceFields() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+  // Unchecked edition has no verification flags.
+  void SetIFieldsUnchecked(ArtField* new_sfields) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-  ArtField* GetInstanceField(uint32_t i)  // TODO: uint16_t
-      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+  uint32_t NumInstanceFields() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    return GetField32(OFFSET_OF_OBJECT_MEMBER(Class, num_instance_fields_));
+  }
 
-  void SetInstanceField(uint32_t i, ArtField* f)  // TODO: uint16_t
-      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+  void SetNumInstanceFields(uint32_t num) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    return SetField32<false>(OFFSET_OF_OBJECT_MEMBER(Class, num_instance_fields_), num);
+  }
+
+  ArtField* GetInstanceField(uint32_t i) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
   // Returns the number of instance fields containing reference types.
   uint32_t NumReferenceInstanceFields() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
@@ -884,17 +886,23 @@ class MANAGED Class FINAL : public Object {
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
   // Gets the static fields of the class.
-  ObjectArray<ArtField>* GetSFields() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+  ArtField* GetSFields() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-  void SetSFields(ObjectArray<ArtField>* new_sfields) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+  void SetSFields(ArtField* new_sfields) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-  uint32_t NumStaticFields() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+  // Unchecked edition has no verification flags.
+  void SetSFieldsUnchecked(ArtField* new_sfields) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-  // TODO: uint16_t
-  ArtField* GetStaticField(uint32_t i) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+  uint32_t NumStaticFields() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    return GetField32(OFFSET_OF_OBJECT_MEMBER(Class, num_static_fields_));
+  }
+
+  void SetNumStaticFields(uint32_t num) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    return SetField32<false>(OFFSET_OF_OBJECT_MEMBER(Class, num_static_fields_), num);
+  }
 
   // TODO: uint16_t
-  void SetStaticField(uint32_t i, ArtField* f) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+  ArtField* GetStaticField(uint32_t i) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
   // Find a static or instance field using the JLS resolution order
   static ArtField* FindField(Thread* self, Handle<Class> klass, const StringPiece& name,
@@ -974,6 +982,10 @@ class MANAGED Class FINAL : public Object {
   static void VisitRoots(RootVisitor* visitor)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
+  template<class Visitor>
+  // Visit field roots.
+  void VisitFieldRoots(Visitor& visitor) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
   // When class is verified, set the kAccPreverified flag on each method.
   void SetPreverifiedFlagOnAllMethods() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
@@ -1079,6 +1091,10 @@ class MANAGED Class FINAL : public Object {
 
   void CheckObjectAlloc() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
+  // Unchecked editions is for root visiting.
+  ArtField* GetSFieldsUnchecked() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+  ArtField* GetIFieldsUnchecked() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
   // defining class loader, or NULL for the "bootstrap" system loader
   HeapReference<ClassLoader> class_loader_;
 
@@ -1096,18 +1112,6 @@ class MANAGED Class FINAL : public Object {
   // static, private, and <init> methods
   HeapReference<ObjectArray<ArtMethod>> direct_methods_;
 
-  // instance fields
-  //
-  // These describe the layout of the contents of an Object.
-  // Note that only the fields directly declared by this class are
-  // listed in ifields; fields declared by a superclass are listed in
-  // the superclass's Class.ifields.
-  //
-  // All instance fields that refer to objects are guaranteed to be at
-  // the beginning of the field list.  num_reference_instance_fields_
-  // specifies the number of reference fields.
-  HeapReference<ObjectArray<ArtField>> ifields_;
-
   // The interface table (iftable_) contains pairs of a interface class and an array of the
   // interface methods. There is one pair per interface supported by this class.  That means one
   // pair for each interface we support directly, indirectly via superclass, or indirectly via a
@@ -1124,9 +1128,6 @@ class MANAGED Class FINAL : public Object {
   // Descriptor for the class such as "java.lang.Class" or "[C". Lazily initialized by ComputeName
   HeapReference<String> name_;
 
-  // Static fields
-  HeapReference<ObjectArray<ArtField>> sfields_;
-
   // The superclass, or NULL if this is java.lang.Object, an interface or primitive type.
   HeapReference<Class> super_class_;
 
@@ -1143,8 +1144,22 @@ class MANAGED Class FINAL : public Object {
   HeapReference<ObjectArray<ArtMethod>> vtable_;
 
   // Access flags; low 16 bits are defined by VM spec.
+  // Note: Shuffled back.
   uint32_t access_flags_;
 
+  // instance fields
+  //
+  // These describe the layout of the contents of an Object.
+  // Note that only the fields directly declared by this class are
+  // listed in ifields; fields declared by a superclass are listed in
+  // the superclass's Class.ifields.
+  //
+  // ArtField arrays are allocated as an array of fields, and not an array of fields pointers.
+  uint64_t ifields_;
+
+  // Static fields
+  uint64_t sfields_;
+
   // Total size of the Class instance; used when allocating storage on gc heap.
   // See also object_size_.
   uint32_t class_size_;
@@ -1160,12 +1175,18 @@ class MANAGED Class FINAL : public Object {
   // TODO: really 16bits
   int32_t dex_type_idx_;
 
+  // Number of static fields.
+  uint32_t num_instance_fields_;
+
   // Number of instance fields that are object refs.
   uint32_t num_reference_instance_fields_;
 
   // Number of static fields that are object refs,
   uint32_t num_reference_static_fields_;
 
+  // Number of static fields.
+  uint32_t num_static_fields_;
+
   // Total object size; used when allocating storage on gc heap.
   // (For interfaces and abstract classes this will be zero.)
   // See also class_size_.