/*

 * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package java.lang.invoke;

import java.lang.annotation.*;

/**

 * A field may be annotated as stable if all of its component variables

 * changes value at most once.

 * A field's value counts as its component value.

 * If the field is typed as an array, then all the non-null components

 * of the array, of depth up to the rank of the field's array type,

 * also count as component values.

 * By extension, any variable (either array or field) which has annotated

 * as stable is called a stable variable, and its non-null or non-zero

 * value is called a stable value.

 * <p>

 * Since all fields begin with a default value of null for references

 * (resp., zero for primitives), it follows that this annotation indicates

 * that the first non-null (resp., non-zero) value stored in the field

 * will never be changed.

 * <p>

 * If the field is not of an array type, there are no array elements,

 * then the value indicated as stable is simply the value of the field.

 * If the dynamic type of the field value is an array but the static type

 * is not, the components of the array are <em>not</em> regarded as stable.

 * <p>

 * If the field is an array type, then both the field value and

 * all the components of the field value (if the field value is non-null)

 * are indicated to be stable.

 * If the field type is an array type with rank {@code N > 1},

 * then each component of the field value (if the field value is non-null),

 * is regarded as a stable array of rank {@code N-1}.

 * <p>

 * Fields which are declared {@code final} may also be annotated as stable.

 * Since final fields already behave as stable values, such an annotation

 * indicates no additional information, unless the type of the field is

 * an array type.

 * <p>

 * It is (currently) undefined what happens if a field annotated as stable

 * is given a third value.  In practice, if the JVM relies on this annotation

 * to promote a field reference to a constant, it may be that the Java memory

 * model would appear to be broken, if such a constant (the second value of the field)

 * is used as the value of the field even after the field value has changed.

 */

/* package-private */

@Target(ElementType.FIELD)

@Retention(RetentionPolicy.RUNTIME)

@interface Stable {

}