001/*
002 * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation.
008 *
009 * This code is distributed in the hope that it will be useful, but WITHOUT
010 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
011 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
012 * version 2 for more details (a copy is included in the LICENSE file that
013 * accompanied this code).
014 *
015 * You should have received a copy of the GNU General Public License version
016 * 2 along with this work; if not, write to the Free Software Foundation,
017 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
018 *
019 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
020 * or visit www.oracle.com if you need additional information or have any
021 * questions.
022 */
023package com.oracle.graal.debug;
024
025import com.sun.management.*;
026
027/**
028 * Tracks memory usage within a scope using {@link ThreadMXBean}. This facility should be employed
029 * using the try-with-resources pattern:
030 *
031 * <pre>
032 * try (DebugMemUseTracker.Closeable a = memUseTracker.start()) {
033 *     // the code to measure
034 * }
035 * </pre>
036 */
037public interface DebugMemUseTracker {
038
039    /**
040     * Creates a point from which memory usage will be recorded if memory use tracking is
041     * {@linkplain Debug#isMemUseTrackingEnabled() enabled}.
042     *
043     * @return an object that must be closed once the activity has completed to add the memory used
044     *         since this call to the total for this tracker
045     */
046    DebugCloseable start();
047
048    /**
049     * Gets the current value of this tracker.
050     */
051    long getCurrentValue();
052}