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/*
* Copyright (c) 2010-2015 Pivotal Software, Inc. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you
* may not use this file except in compliance with the License. You
* may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
* implied. See the License for the specific language governing
* permissions and limitations under the License. See accompanying
* LICENSE file.
*/
package com.gemstone.gemfire.internal.offheap;
import com.gemstone.gemfire.internal.SharedLibrary;
import com.gemstone.gemfire.internal.shared.unsafe.UnsafeHolder;
import com.gemstone.gemfire.pdx.internal.unsafe.UnsafeWrapper;
public final class UnsafeMemoryChunk implements MemoryChunk {
private static final boolean USE_SAFE_COPY_MEMORY = Boolean.getBoolean("gemfire.OFF_HEAP_USE_SAFE_COPY_MEMORY");
private static final UnsafeWrapper unsafe;
static {
unsafe = new UnsafeWrapper();
}
private final long data;
private final int size;
public UnsafeMemoryChunk(int size) {
assert size >= 0;
try {
this.data = unsafe.allocateMemory(size);
this.size = size;
} catch (OutOfMemoryError err) {
String msg = "Failed creating " + size + " bytes of off-heap memory during cache creation.";
if (err.getMessage() != null && !err.getMessage().isEmpty()) {
msg += " Cause: " + err.getMessage();
}
if (!SharedLibrary.is64Bit() && size >= (1024*1024*1024)) {
msg += " The JVM looks like a 32-bit one. For large amounts of off-heap memory a 64-bit JVM is needed.";
}
throw new OutOfMemoryError(msg);
}
}
public static int getPageSize() {
return unsafe.getPageSize();
}
@Override
public int getSize() {
return (int)this.size;
}
public long getMemoryAddress() {
return this.data;
}
public static UnsafeWrapper getUnsafeWrapper() {
return unsafe;
}
/**
* Compare the first 'size' bytes at addr1 to those at addr2 and return true
* if they are all equal.
*/
public static boolean compareUnsafeBytes(long addr1, long addr2, int size) {
final UnsafeWrapper unsafe = getUnsafeWrapper();
if ((size >= 8) && ((addr1 & 7) == 0) && ((addr2 & 7) == 0)) {
// We have 8 or more bytes to compare and the addresses are 8 byte aligned
do {
if (unsafe.getLong(addr1) != unsafe.getLong(addr2)) {
return false;
}
size -= 8;
addr1 += 8;
addr2 += 8;
} while (size >= 8);
}
while (size > 0) {
if (unsafe.getByte(addr1) != unsafe.getByte(addr2)) {
return false;
}
size--;
addr1++;
addr2++;
}
return true;
}
/**
* Reads from "addr" to "bytes". Number of bytes read/written is provided as
* argument.
*/
public static void readUnsafeBytes(final UnsafeWrapper unsafe,
final long addr, final byte[] bytes, final int length) {
assert SimpleMemoryAllocatorImpl.validateAddressAndSizeWithinSlab(addr,
length);
unsafe.copyMemory(null, addr, bytes, UnsafeHolder.arrayBaseOffset, length);
}
/**
* Reads from "offset" bytes after "addr" to "bytes". Number of bytes
* read/written is provided as argument. The "offset" argument is being sent
* separately instead of added in addr itself to workaround JDK bug in #51350
* (see https://reviewboard.gemstone.com/r/3246 for more details).
*/
public static void readUnsafeBytes(final UnsafeWrapper unsafe, long addr,
int offset, final byte[] bytes, int bytesOffset, int length) {
assert SimpleMemoryAllocatorImpl.validateAddressAndSizeWithinSlab(addr,
length + offset);
unsafe.copyMemory(null, addr + offset, bytes, UnsafeHolder.arrayBaseOffset
+ bytesOffset, length);
}
public static byte readAbsoluteByte(long addr) {
assert SimpleMemoryAllocatorImpl.validateAddressAndSizeWithinSlab(addr, 1);
return unsafe.getByte(addr);
}
public static int readAbsoluteInt(long addr) {
assert SimpleMemoryAllocatorImpl.validateAddressAndSizeWithinSlab(addr, Integer.SIZE/Byte.SIZE);
return unsafe.getInt(addr);
}
public static int readAbsoluteIntVolatile(long addr) {
assert SimpleMemoryAllocatorImpl.validateAddressAndSizeWithinSlab(addr, Integer.SIZE/Byte.SIZE);
return unsafe.getIntVolatile(null, addr);
}
public static long readAbsoluteLong(long addr) {
assert SimpleMemoryAllocatorImpl.validateAddressAndSizeWithinSlab(addr, Long.SIZE/Byte.SIZE);
return unsafe.getLong(addr);
}
public static long readAbsoluteLongVolatile(long addr) {
assert SimpleMemoryAllocatorImpl.validateAddressAndSizeWithinSlab(addr, Long.SIZE/Byte.SIZE);
return unsafe.getLongVolatile(null, addr);
}
@Override
public byte readByte(int offset) {
assert SimpleMemoryAllocatorImpl.validateAddressAndSizeWithinSlab(this.data+offset, 1);
return readAbsoluteByte(this.data+offset);
}
public static void writeAbsoluteByte(long addr, byte value) {
assert SimpleMemoryAllocatorImpl.validateAddressAndSizeWithinSlab(addr, 1);
unsafe.putByte(addr, value);
}
public static void writeAbsoluteInt(long addr, int value) {
assert SimpleMemoryAllocatorImpl.validateAddressAndSizeWithinSlab(addr, Integer.SIZE/Byte.SIZE);
unsafe.putInt(null, addr, value);
}
public static void writeAbsoluteIntVolatile(long addr, int value) {
assert SimpleMemoryAllocatorImpl.validateAddressAndSizeWithinSlab(addr, Integer.SIZE/Byte.SIZE);
unsafe.putIntVolatile(null, addr, value);
}
public static boolean writeAbsoluteIntVolatile(long addr, int expected, int value) {
assert SimpleMemoryAllocatorImpl.validateAddressAndSizeWithinSlab(addr, Integer.SIZE/Byte.SIZE);
return unsafe.compareAndSwapInt(null, addr, expected, value);
}
public static void writeAbsoluteLong(long addr, long value) {
assert SimpleMemoryAllocatorImpl.validateAddressAndSizeWithinSlab(addr, Long.SIZE/Byte.SIZE);
unsafe.putLong(null, addr, value);
}
public static void writeAbsoluteLongVolatile(long addr, long value) {
assert SimpleMemoryAllocatorImpl.validateAddressAndSizeWithinSlab(addr, Long.SIZE/Byte.SIZE);
unsafe.putLongVolatile(null, addr, value);
}
public static boolean writeAbsoluteLongVolatile(long addr, long expected, long value) {
assert SimpleMemoryAllocatorImpl.validateAddressAndSizeWithinSlab(addr, Long.SIZE/Byte.SIZE);
return unsafe.compareAndSwapLong(null, addr, expected, value);
}
@Override
public void writeByte(int offset, byte value) {
writeAbsoluteByte(this.data+offset, value);
}
public static void readAbsoluteBytes(long addr, int addrOffset, byte[] bytes) {
readAbsoluteBytes(addr, addrOffset, bytes, 0, bytes.length);
}
@Override
public void readBytes(int offset, byte[] bytes) {
readBytes(offset, bytes, 0, bytes.length);
}
public static void writeAbsoluteBytes(long addr, byte[] bytes) {
writeAbsoluteBytes(addr, bytes, 0, bytes.length);
}
public static void clearAbsolute(long addr, int size) {
assert size >= 0: "Size=" + size + ", but size must be >= 0";
assert SimpleMemoryAllocatorImpl.validateAddressAndSizeWithinSlab(addr, size);
unsafe.setMemory(addr, size, (byte) 0);
}
@Override
public void writeBytes(int offset, byte[] bytes) {
writeBytes(offset, bytes, 0, bytes.length);
}
// the addrOffset argument is being sent separately instead of added in addr
// itself to workaround JDK bug in #51350
public static void readAbsoluteBytes(long addr, int addrOffset, byte[] bytes,
int bytesOffset, int size) {
// Throwing an Error instead of using the "assert" keyword because passing < 0 to
// copyMemory(...) can lead to a core dump with some JVMs and we don't want to
// require the -ea JVM flag.
if (size < 0) {
throw new AssertionError("Size=" + size + ", but size must be >= 0");
}
assert addrOffset >= 0: "AddrOffset=" + addrOffset + ", but addrOffset must be >= 0";
assert bytesOffset >= 0: "BytesOffset=" + bytesOffset + ", but bytesOffset must be >= 0";
assert bytesOffset + size <= bytes.length: "BytesOffset=" + bytesOffset + ",size=" + size + ",bytes.length=" + bytes.length + ", but bytesOffset + size must be <= " + bytes.length;
if (size == 0) {
return; // No point in wasting time copying 0 bytes
}
assert SimpleMemoryAllocatorImpl.validateAddressAndSizeWithinSlab(addr,
size + addrOffset);
addr += addrOffset;
if (USE_SAFE_COPY_MEMORY) {
for (int i = 0; i < size; i++) {
bytes[bytesOffset+i] = unsafe.getByte(addr+i);
}
} else {
unsafe.copyMemory(null, addr, bytes, UnsafeHolder.arrayBaseOffset
+ bytesOffset, size);
}
}
@Override
public void readBytes(int offset, byte[] bytes, int bytesOffset, int size) {
readAbsoluteBytes(this.data, offset, bytes, bytesOffset, size);
}
public static void writeAbsoluteBytes(long addr, byte[] bytes, int bytesOffset, int size) {
// Throwing an Error instead of using the "assert" keyword because passing < 0 to
// copyMemory(...) can lead to a core dump with some JVMs and we don't want to
// require the -ea JVM flag.
if (size < 0) {
throw new AssertionError("Size=" + size + ", but size must be >= 0");
}
assert bytesOffset >= 0: "BytesOffset=" + bytesOffset + ", but bytesOffset must be >= 0";
assert bytesOffset + size <= bytes.length: "BytesOffset=" + bytesOffset + ",size=" + size + ",bytes.length=" + bytes.length + ", but bytesOffset + size must be <= " + bytes.length;
if (size == 0) {
return; // No point in wasting time copying 0 bytes
}
assert SimpleMemoryAllocatorImpl.validateAddressAndSizeWithinSlab(addr, size);
if (USE_SAFE_COPY_MEMORY) {
for (int i = 0; i < size; i++) {
unsafe.putByte(addr+i, bytes[bytesOffset+i]);
}
} else {
unsafe.copyMemory(bytes, UnsafeHolder.arrayBaseOffset + bytesOffset,
null, addr, size);
}
}
public static void fill(long addr, int size, byte fill) {
assert size >= 0: "Size=" + size + ", but size must be >= 0";
unsafe.setMemory(addr, size, fill);
}
@Override
public void writeBytes(int offset, byte[] bytes, int bytesOffset, int size) {
writeAbsoluteBytes(this.data+offset, bytes, bytesOffset, size);
}
@Override
public void release() {
unsafe.freeMemory(this.data);
}
@Override
public void copyBytes(int src, int dst, int size) {
assert size >= 0: "Size=" + size + ", but size must be >= 0";
assert SimpleMemoryAllocatorImpl.validateAddressAndSizeWithinSlab(this.data+src, size);
assert SimpleMemoryAllocatorImpl.validateAddressAndSizeWithinSlab(this.data+dst, size);
unsafe.copyMemory(this.data+src, this.data+dst, size);
}
@Override
public String toString() {
final StringBuilder sb = new StringBuilder(getClass().getSimpleName());
sb.append("{");
sb.append("MemoryAddress=").append(getMemoryAddress());
sb.append(", Size=").append(getSize());
sb.append("}");
return sb.toString();
}
}