| /* |
| * Copyright (c) 2017, 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 org.graalvm.compiler.options; |
| |
| import java.util.concurrent.atomic.AtomicReference; |
| |
| import jdk.internal.vm.compiler.collections.EconomicMap; |
| import jdk.internal.vm.compiler.collections.Equivalence; |
| import jdk.internal.vm.compiler.collections.UnmodifiableEconomicMap; |
| import jdk.internal.vm.compiler.collections.UnmodifiableMapCursor; |
| |
| /** |
| * A context for obtaining values for {@link OptionKey}s that allows for key/value pairs to be |
| * updated. Updates have atomic copy-on-write semantics which means a thread may see an old value |
| * when reading but writers will never loose updates. |
| */ |
| public class ModifiableOptionValues extends OptionValues { |
| |
| private final AtomicReference<UnmodifiableEconomicMap<OptionKey<?>, Object>> v = new AtomicReference<>(); |
| |
| private static final EconomicMap<OptionKey<?>, Object> EMPTY_MAP = newOptionMap(); |
| |
| public ModifiableOptionValues(UnmodifiableEconomicMap<OptionKey<?>, Object> values) { |
| super(EMPTY_MAP); |
| EconomicMap<OptionKey<?>, Object> map = newOptionMap(); |
| initMap(map, values); |
| v.set(map); |
| } |
| |
| /** |
| * Value that can be used in {@link #update(UnmodifiableEconomicMap)} and |
| * {@link #update(OptionKey, Object)} to remove an explicitly set value for a key such that |
| * {@link OptionKey#hasBeenSet(OptionValues)} will return {@code false} for the key. |
| */ |
| public static final Object UNSET_KEY = new Object(); |
| |
| /** |
| * Updates this object with the given key/value pair. |
| * |
| * @see #UNSET_KEY |
| */ |
| public void update(OptionKey<?> key, Object value) { |
| UnmodifiableEconomicMap<OptionKey<?>, Object> expect; |
| EconomicMap<OptionKey<?>, Object> newMap; |
| do { |
| expect = v.get(); |
| newMap = EconomicMap.create(Equivalence.IDENTITY, expect); |
| if (value == UNSET_KEY) { |
| newMap.removeKey(key); |
| } else { |
| key.update(newMap, value); |
| // Need to do the null encoding here as `key.update()` doesn't do it |
| newMap.put(key, encodeNull(value)); |
| } |
| } while (!v.compareAndSet(expect, newMap)); |
| } |
| |
| /** |
| * Updates this object with the key/value pairs in {@code values}. |
| * |
| * @see #UNSET_KEY |
| */ |
| public void update(UnmodifiableEconomicMap<OptionKey<?>, Object> values) { |
| if (values.isEmpty()) { |
| return; |
| } |
| UnmodifiableEconomicMap<OptionKey<?>, Object> expect; |
| EconomicMap<OptionKey<?>, Object> newMap; |
| do { |
| expect = v.get(); |
| newMap = EconomicMap.create(Equivalence.IDENTITY, expect); |
| UnmodifiableMapCursor<OptionKey<?>, Object> cursor = values.getEntries(); |
| while (cursor.advance()) { |
| OptionKey<?> key = cursor.getKey(); |
| Object value = cursor.getValue(); |
| if (value == UNSET_KEY) { |
| newMap.removeKey(key); |
| } else { |
| key.update(newMap, value); |
| // Need to do the null encoding here as `key.update()` doesn't do it |
| newMap.put(key, encodeNull(value)); |
| } |
| } |
| } while (!v.compareAndSet(expect, newMap)); |
| } |
| |
| @Override |
| protected <T> T get(OptionKey<T> key) { |
| return OptionValues.get(v.get(), key); |
| } |
| |
| @Override |
| protected boolean containsKey(OptionKey<?> key) { |
| return v.get().containsKey(key); |
| } |
| |
| @Override |
| public UnmodifiableEconomicMap<OptionKey<?>, Object> getMap() { |
| return v.get(); |
| } |
| } |