--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.jfr/share/classes/jdk/jfr/consumer/ConstantMap.java Tue May 15 20:24:34 2018 +0200
@@ -0,0 +1,139 @@
+/*
+ * Copyright (c) 2016, 2018, 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
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.jfr.consumer;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Holds mapping between a set of keys and their corresponding object.
+ *
+ * If the type is a known type, i.e. {@link RecordedThread}, an
+ * {@link ObjectFactory} can be supplied which will instantiate a typed object.
+ */
+final class ConstantMap {
+ private final static class Reference {
+ private final long key;
+ private final ConstantMap pool;
+
+ Reference(ConstantMap pool, long key) {
+ this.pool = pool;
+ this.key = key;
+ }
+
+ Object resolve() {
+ return pool.get(key);
+ }
+ }
+
+ private final ObjectFactory<?> factory;
+ private final LongMap<Object> objects;
+
+ private LongMap<Boolean> isResolving;
+ private boolean allResolved;
+ private String name;
+
+ ConstantMap(ObjectFactory<?> factory, String name) {
+ this.name = name;
+ this.objects = new LongMap<>();
+ this.factory = factory;
+ }
+
+ Object get(long id) {
+ // fast path, all objects in pool resolved
+ if (allResolved) {
+ return objects.get(id);
+ }
+ // referenced from a pool, deal with this later
+ if (isResolving == null) {
+ return new Reference(this, id);
+ }
+
+ Boolean beingResolved = isResolving.get(id);
+
+ // we are resolved (but not the whole pool)
+ if (Boolean.FALSE.equals(beingResolved)) {
+ return objects.get(id);
+ }
+
+ // resolving ourself, abort to avoid infinite recursion
+ if (Boolean.TRUE.equals(beingResolved)) {
+ return null;
+ }
+
+ // resolve me!
+ isResolving.put(id, Boolean.TRUE);
+ Object resolved = resolve(objects.get(id));
+ isResolving.put(id, Boolean.FALSE);
+ if (factory != null) {
+ Object factorized = factory.createObject(id, resolved);
+ objects.put(id, factorized);
+ return factorized;
+ } else {
+ objects.put(id, resolved);
+ return resolved;
+ }
+ }
+
+ private static Object resolve(Object o) {
+ if (o instanceof Reference) {
+ return resolve(((Reference) o).resolve());
+ }
+ if (o != null && o.getClass().isArray()) {
+ final Object[] array = (Object[]) o;
+ for (int i = 0; i < array.length; i++) {
+ array[i] = resolve(array[i]);
+ }
+ return array;
+ }
+ return o;
+ }
+
+ public void resolve() {
+ List<Long> keyList = new ArrayList<>();
+ objects.keys().forEachRemaining(keyList::add);
+ for (Long l : keyList) {
+ get(l);
+ }
+ }
+
+ public void put(long key, Object value) {
+ objects.put(key, value);
+ }
+
+ public void setIsResolving() {
+ isResolving = new LongMap<>();
+ }
+
+ public void setResolved() {
+ allResolved = true;
+ isResolving = null; // pool finished, release memory
+ }
+
+ public String getName() {
+ return name;
+ }
+}