Mercurial > hg > graal-jvmci-8
view jvmci/jdk.vm.ci.options/src/jdk/vm/ci/options/StableOptionValue.java @ 22672:1bbd4a7c274b
Rename jdk.internal.jvmci to jdk.vm.ci
author | Tom Rodriguez <tom.rodriguez@oracle.com> |
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date | Thu, 08 Oct 2015 17:28:41 -0700 |
parents | jvmci/jdk.internal.jvmci.options/src/jdk/internal/jvmci/options/StableOptionValue.java@0e095e2c24e2 |
children |
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/* * Copyright (c) 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. * * 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 * or visit www.oracle.com if you need additional information or have any * questions. */ package jdk.vm.ci.options; /** * An option that always returns the same {@linkplain #getValue() value}. */ public class StableOptionValue<T> extends OptionValue<T> { /** * Creates a stable option value. */ public StableOptionValue(T value) { super(value); } /** * Used to assert the invariant for stability. Without using locks, this check is not safe * against races and so it's only an assertion. */ private boolean getValueCalled; /** * Creates an uninitialized stable option value for a subclass that initializes itself * {@link #defaultValue() lazily}. */ public StableOptionValue() { } /** * Gets the value of this option. */ @Override public final T getValue() { T result = super.getValue(); assert initGetValueCalled(); return result; } private boolean initGetValueCalled() { getValueCalled = true; return true; } /** * {@inheritDoc} * <p> * This must only be called if {@link #getValue()} has never been called. */ @Override public final void setValue(Object v) { assert !getValueCalled; super.setValue(v); } }