AssertionContainer.java

/*
 * Copyright (c) 2014, 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.
 *
 * 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 gc.g1.unloading.check;

import java.util.*;

/**
 * This is the storage for assertions. Here assertions are stored until required number of garbage collections happen.
 * This container isn't thread-safe.
 */
public class AssertionContainer {

    private SortedMap<Long, List<Assertion>> sortedMap = new TreeMap<>();

    /**
     * Enqueue assertion to storage.
     * @param assertions
     * @param gcCounter - gc counter value as of assertion created
     */
    public void enqueue(Collection<Assertion> assertions, Long gcCounter) {
        if (sortedMap.get(gcCounter) != null) {
            sortedMap.get(gcCounter).addAll(assertions);
        } else {
            List<Assertion> newList = new LinkedList<>();
            newList.addAll(assertions);
            sortedMap.put(gcCounter, newList);
        }
    }

    /**
     * Get assertions that are ready for check. That means they where created when gc counter was less then
     * specified value.
     * @param bound - value of gc counter
     * @return - collection of assertions. It can be empty if no assertions are mature yet.
     */
    public Collection<Assertion> getElder(Long bound) {
        Collection<Assertion> returnValue = new LinkedList<>();
        SortedMap<Long, List<Assertion>> filteredView = sortedMap.headMap(bound);
        for (Long l : filteredView.keySet()) {
            List<Assertion> list = filteredView.remove(l);
            returnValue.addAll(list);
        }
        return returnValue;
    }

}