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/*
* Copyright (C) 2016 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package dalvik.system;
/**
* Holder class for extraneous Class data.
*
* This class holds data for Class objects that is either rarely useful, only necessary for
* debugging purposes or both. This allows us to extend the Class class without impacting memory
* use.
*
* @hide For internal runtime use only.
*/
public final class ClassExt {
/**
* A Pointer-sized-array of instance jfieldIDs in the same order as the ifields_ array.
* The jfieldID is associated with the ArtField at the corresonding index in the ifields_ array.
*/
private Object instanceJfieldIDs;
/**
* A Pointer-sized-array of jmethodIDS in the same order as the methods_
* array. The jmethodID is associated with the ArtField at the corresonding
* index in the methods_ array.
*/
private Object jmethodIDs;
/**
* If the class has undergone structural redefinition, the now obsolete class object.
*
* Needed to ensure that the class isn't unloaded before its jit code is. Normally this is
* handled by the classloader but since the class is now obsolete it's no longer held live
* there and instead we must do so manually. This class should not be used for anything.
*/
private Class<?> obsoleteClass;
/**
* An array of all obsolete DexCache objects that are needed for obsolete methods.
*
* These entries are associated with the obsolete ArtMethod pointers at the same indexes in the
* obsoleteMethods array.
*
* This field has native components and is a logical part of the 'Class' type.
*/
private Object[] obsoleteDexCaches;
/**
* An array of all native obsolete ArtMethod pointers.
*
* These are associated with their DexCaches at the same index in the obsoleteDexCaches array.
*
* This field is actually either an int[] or a long[] depending on size of a pointer.
*
* This field contains native pointers and is a logical part of the 'Class' type.
*/
private Object obsoleteMethods;
/**
* If set, the bytes, native pointer (as a java.lang.Long), or DexCache of the original dex-file
* associated with the related class.
*
* In this instance 'original' means either (1) the dex-file loaded for this class when it was
* first loaded after all non-retransformation capable transformations had been performed but
* before any retransformation capable ones had been done or (2) the most recent dex-file bytes
* given for a class redefinition.
*
* Needed in order to implement retransformation of classes.
*
* This field is a logical part of the 'Class' type.
*/
private Object originalDexFile;
/**
* A Pointer-sized-array of static jfieldIDs in the same order as the sfields_ array.
* The jfieldID is associated with the ArtField at the corresonding index in the sfields_ array.
*/
private Object staticJfieldIDs;
/**
* If class verify fails, we must return same error on subsequent tries. We may store either
* the class of the error, or an actual instance of Throwable here.
*
* This field is a logical part of the 'Class' type.
*/
private Object verifyError;
/**
* If set, native pointer to the initial, pre-redefine, dex file associated with the related
* class. This is different from the {@code originalDexFile} which is the pre-retransform dex
* file, i.e. could contain the bytes of the dex file provided during redefine.
*
* It is enough to store the native pointer because the pre-redefine dex file is either part
* of boot classpath or it is being kept alive by its class loader. Class loaders always keep
* dex files alive even if all their classes have been redefined.
*
* Needed in order to preserve access to dex-level hiddenapi flags after JVMTI redefine.
*
* This field is a logical part of the 'Class' type.
*/
private long preRedefineDexFilePtr;
/**
* ClassDef index of the related class in the pre-redefine dex file. Set together with
* {@code preRedefineDexFilePtr}.
*
* Needed in order to preserve access to dex-level hiddenapi flags after JVMTI redefine.
*
* This field is a logical part of the 'Class' type.
*/
private int preRedefineClassDefIndex;
/**
* Private constructor.
*
* Only created by the runtime.
*/
private ClassExt() {}
}
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