SpecificResourceAllocator.java

/*
 * Copyright 2013 Ytai Ben-Tsvi. All rights reserved.
 *  
 * 
 * Redistribution and use in source and binary forms, with or without modification, are
 * permitted provided that the following conditions are met:
 * 
 *    1. Redistributions of source code must retain the above copyright notice, this list of
 *       conditions and the following disclaimer.
 * 
 *    2. Redistributions in binary form must reproduce the above copyright notice, this list
 *       of conditions and the following disclaimer in the documentation and/or other materials
 *       provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL ARSHAN POURSOHI OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 * The views and conclusions contained in the software and documentation are those of the
 * authors and should not be interpreted as representing official policies, either expressed
 * or implied.
 */
package ioio.lib.impl;

import ioio.lib.impl.ResourceManager.Resource;

class SpecificResourceAllocator implements ResourceManager.ResourceAllocator {
    private final boolean[] claimed_;
    private final int offset_;

    public SpecificResourceAllocator(int offset, int count) {
        offset_ = offset;
        claimed_ = new boolean[count];
    }

    @Override
    public synchronized void alloc(Resource r) {
        try {
            if (claimed_[r.id - offset_]) {
                throw new IllegalArgumentException("Resource already claimed: " + r);
            }
            claimed_[r.id - offset_] = true;
        } catch (IndexOutOfBoundsException e) {
            throw new IllegalArgumentException("Resource doesn't exist: " + r);
        }
    }

    @Override
    public synchronized void free(Resource r) {
        if (!claimed_[r.id - offset_]) {
            throw new IllegalArgumentException("Resource not claimed: " + r);
        }
        claimed_[r.id - offset_] = false;
    }
}