1 /*
  2  * Copyright (c) 2007, 2021, 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 import jdk.internal.access.foreign.UnmapperProxy;
 30 import jdk.internal.misc.ScopedMemoryAccess.Scope;
 31 import jdk.internal.misc.VM.BufferPool;
 32 
 33 import java.io.FileDescriptor;
 34 import java.nio.Buffer;
 35 import java.nio.ByteBuffer;
 36 
 37 public interface JavaNioAccess {
 38 
 39     /**
 40      * Used by {@code jdk.internal.misc.VM}.
 41      */
 42     BufferPool getDirectBufferPool();
 43 
 44     /**
 45      * Constructs a direct ByteBuffer referring to the block of memory starting
 46      * at the given memory address and extending {@code cap} bytes.
 47      * The {@code ob} parameter is an arbitrary object that is attached
 48      * to the resulting buffer.
 49      * Used by {@code jdk.internal.foreignMemorySegmentImpl}.
 50      */
 51     ByteBuffer newDirectByteBuffer(long addr, int cap, Object obj, MemorySegmentProxy segment);
 52 
 53     /**
 54      * Constructs a mapped ByteBuffer referring to the block of memory starting
 55      * at the given memory address and extending {@code cap} bytes.
 56      * The {@code ob} parameter is an arbitrary object that is attached
 57      * to the resulting buffer. The {@code sync} and {@code fd} parameters of the mapped
 58      * buffer are derived from the {@code UnmapperProxy}.
 59      * Used by {@code jdk.internal.foreignMemorySegmentImpl}.
 60      */
 61     ByteBuffer newMappedByteBuffer(UnmapperProxy unmapperProxy, long addr, int cap, Object obj, MemorySegmentProxy segment);
 62 
 63     /**
 64      * Constructs an heap ByteBuffer with given backing array, offset, capacity and segment.
 65      * Used by {@code jdk.internal.foreignMemorySegmentImpl}.
 66      */
 67     ByteBuffer newHeapByteBuffer(byte[] hb, int offset, int capacity, MemorySegmentProxy segment);
 68 
 69     /**
 70      * Used by {@code jdk.internal.foreign.Utils}.
 71      */
 72     Object getBufferBase(ByteBuffer bb);
 73 
 74     /**
 75      * Used by {@code jdk.internal.foreign.Utils}.
 76      */
 77     long getBufferAddress(ByteBuffer bb);
 78 
 79     /**
 80      * Used by {@code jdk.internal.foreign.Utils}.
 81      */
 82     UnmapperProxy unmapper(ByteBuffer bb);
 83 
 84     /**
 85      * Used by {@code jdk.internal.foreign.AbstractMemorySegmentImpl} and byte buffer var handle views.
 86      */
 87     MemorySegmentProxy bufferSegment(Buffer buffer);
 88 
 89     /**
 90      * Used by I/O operations to make a buffer's resource scope non-closeable
 91      * (for the duration of the I/O operation) by acquiring a new resource
 92      * scope handle. Null is returned if the buffer has no scope, or
 93      * acquiring is not required to guarantee safety.
 94      */
 95     Runnable acquireScope(Buffer buffer, boolean async);
 96 
 97     /**
 98      * Used by {@code jdk.internal.foreign.MappedMemorySegmentImpl} and byte buffer var handle views.
 99      */
100     void force(FileDescriptor fd, long address, boolean isSync, long offset, long size);
101 
102     /**
103      * Used by {@code jdk.internal.foreign.MappedMemorySegmentImpl} and byte buffer var handle views.
104      */
105     void load(long address, boolean isSync, long size);
106 
107     /**
108      * Used by {@code jdk.internal.foreign.MappedMemorySegmentImpl}.
109      */
110     void unload(long address, boolean isSync, long size);
111 
112     /**
113      * Used by {@code jdk.internal.foreign.MappedMemorySegmentImpl} and byte buffer var handle views.
114      */
115     boolean isLoaded(long address, boolean isSync, long size);
116 
117     /**
118      * Used by {@code jdk.internal.foreign.NativeMemorySegmentImpl}.
119      */
120     void reserveMemory(long size, long cap);
121 
122     /**
123      * Used by {@code jdk.internal.foreign.NativeMemorySegmentImpl}.
124      */
125     void unreserveMemory(long size, long cap);
126 
127     /**
128      * Used by {@code jdk.internal.foreign.NativeMemorySegmentImpl}.
129      */
130     int pageSize();
131 }