ojluni/src/main/java/sun/java2d/xr/XcbRequestCounter.java

/*
 * Copyright (c) 2010, 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.
 *
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package sun.java2d.xr;

/**
 * UInt32 "emulation", mimics the behaviour of xcb's request counter.
 * In order to be compatible with xcb we have to wrap exactly when xcb would do.
 * @author Clemens Eisserer
 */

public class XcbRequestCounter {
    private final static long MAX_UINT = 4294967295L;

    long value;

    public XcbRequestCounter(long value) {
        this.value = value;
    }

    public void setValue(long value) {
        this.value = value;
    }

    public long getValue() {
        return value;
    }

    public void add(long v) {
        value += v;

        /*Handle 32-bit unsigned int overflow*/
        if (value > MAX_UINT) {
            value = 0; //-= MAX_UINT; //Shouldn't that be zero?!?!
        }
    }
}