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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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.
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package com.sun.max.vm.heap.gcx;

import com.sun.max.unsafe.*;

/**
 * A more elaborated refill manager for linear space allocator.
 * It implements a refill policy that decides whether refill is warranted. If denied, the allocator
 * must issue an overflow allocation request, otherwise it issues a refill request.
 * Additionally, a method for handling large allocation requests that should never be handled
 * by the linear space allocator is provided.
 */
public abstract class RefillManager extends Refiller {
    /**
     * Called directly by the allocator if there isn't enough
     * space left to satisfy request and the refill manager rejected the refill.
     *
     * @param size number of bytes requested
     * @return the address to a contiguous region of the requested size
     */
    public abstract Address allocateOverflow(Size size);

    /**
     * Tell whether the amount of space left warrants a refill.
     * @param requestedSpace initial space requested
     * @param spaceLeft space left in the allocator requesting refill
     *
     * @return a boolean indicating whether refill should be done
     */
    public abstract boolean shouldRefill(Size requestedSpace, Size spaceLeft);
}