1 /*
   2  * Copyright (c) 2007, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.internal.access;
  27 
  28 import jdk.internal.access.foreign.MemorySegmentProxy;
  29 
  30 import java.nio.Buffer;
  31 import java.nio.ByteBuffer;
  32 
  33 public interface JavaNioAccess {
  34     /**
  35      * Provides access to information on buffer usage.
  36      */
  37     interface BufferPool {
  38         String getName();
  39         long getCount();
  40         long getTotalCapacity();
  41         long getMemoryUsed();
  42     }
  43     BufferPool getDirectBufferPool();
  44 
  45     /**
  46      * Constructs a direct ByteBuffer referring to the block of memory starting
  47      * at the given memory address and extending {@code cap} bytes.
  48      * The {@code ob} parameter is an arbitrary object that is attached
  49      * to the resulting buffer.
  50      * Used by {@code jdk.internal.foreignMemorySegmentImpl}.
  51      */
  52     ByteBuffer newDirectByteBuffer(long addr, int cap, Object obj, MemorySegmentProxy segment);
  53 
  54     /**
  55      * Constructs an heap ByteBuffer with given backing array, offset, capacity and segment.
  56      * Used by {@code jdk.internal.foreignMemorySegmentImpl}.
  57      */
  58     ByteBuffer newHeapByteBuffer(byte[] hb, int offset, int capacity, MemorySegmentProxy segment);
  59 
  60     /**
  61      * Used by {@code jdk.internal.foreign.Utils}.
  62      */
  63     Object getBufferBase(ByteBuffer bb);
  64 
  65     /**
  66      * Used by {@code jdk.internal.foreign.Utils}.
  67      */
  68     long getBufferAddress(ByteBuffer bb);
  69 
  70     /**
  71      * Used by byte buffer var handle views.
  72      */
  73     void checkSegment(Buffer buffer);
  74 }