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/* * Copyright (c) 2000, 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. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package sun.nio.ch; import java.nio.ByteBuffer;import sun.misc.*;  /** * Manipulates a native array of iovec structs on Solaris: * * typedef struct iovec { *    caddr_t  iov_base;      int      iov_len; * } iovec_t; * * @author Mike McCloskey * @since 1.4 */ class IOVecWrapper {     // Miscellaneous constants    private static final int BASE_OFFSET = 0;    private static final int LEN_OFFSET;    private static final int SIZE_IOVEC;     // The iovec array    private final AllocatedNativeObject vecArray;     // Number of elements in iovec array    private final int size;     // Buffers and position/remaining corresponding to elements in iovec array    private final ByteBuffer[] buf;    private final int[] position;    private final int[] remaining;     // Shadow buffers for cases when original buffer is substituted    private final ByteBuffer[] shadow;     // Base address of this array    final long address;     // Address size in bytes    static int addressSize;     private static class Deallocator implements Runnable {        private final AllocatedNativeObject obj;        Deallocator(AllocatedNativeObject obj) {            this.obj = obj;        }        public void run() {            obj.free();        }    }     // per thread IOVecWrapper    private static final ThreadLocal<IOVecWrapper> cached =        new ThreadLocal<IOVecWrapper>();     private IOVecWrapper(int size) {        this.size      = size;        this.buf       = new ByteBuffer[size];        this.position  = new int[size];        this.remaining = new int[size];        this.shadow    = new ByteBuffer[size];        this.vecArray  = new AllocatedNativeObject(size * SIZE_IOVEC, false);        this.address   = vecArray.address();    }     static IOVecWrapper get(int size) {        IOVecWrapper wrapper = cached.get();        if (wrapper != null && wrapper.size < size) {            // not big enough; eagerly release memory            wrapper.vecArray.free();            wrapper = null;        }        if (wrapper == null) {            wrapper = new IOVecWrapper(size);            Cleaner.create(wrapper, new Deallocator(wrapper.vecArray));            cached.set(wrapper);        }        return wrapper;    }     void setBuffer(int i, ByteBuffer buf, int pos, int rem) {        this.buf[i] = buf;        this.position[i] = pos;        this.remaining[i] = rem;    }     void setShadow(int i, ByteBuffer buf) {        shadow[i] = buf;    }     ByteBuffer getBuffer(int i) {        return buf[i];    }     int getPosition(int i) {        return position[i];    }     int getRemaining(int i) {        return remaining[i];    }     ByteBuffer getShadow(int i) {        return shadow[i];    }     void clearRefs(int i) {        buf[i] = null;        shadow[i] = null;    }     void putBase(int i, long base) {        int offset = SIZE_IOVEC * i + BASE_OFFSET;        if (addressSize == 4)            vecArray.putInt(offset, (int)base);        else            vecArray.putLong(offset, base);    }     void putLen(int i, long len) {        int offset = SIZE_IOVEC * i + LEN_OFFSET;        if (addressSize == 4)            vecArray.putInt(offset, (int)len);        else            vecArray.putLong(offset, len);    }     static {        addressSize = Util.unsafe().addressSize();        LEN_OFFSET = addressSize;        SIZE_IOVEC = (short) (addressSize * 2);    }}