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/**
* Copyright 2019 JogAmp Community. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are
* permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this list of
* conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice, this list
* of conditions and the following disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* The views and conclusions contained in the software and documentation are those of the
* authors and should not be interpreted as representing official policies, either expressed
* or implied, of JogAmp Community.
*/
package com.jogamp.common.util;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.nio.ByteBuffer;
import java.security.AccessController;
import java.security.PrivilegedAction;
import com.jogamp.common.ExceptionUtils;
import jogamp.common.Debug;
import jogamp.common.os.PlatformPropsImpl;
/**
* Utility methods allowing easy access to certain {@link sun.misc.Unsafe} functionality.
*/
public class UnsafeUtil {
static final boolean DEBUG;
static {
DEBUG = Debug.debug("UnsafeUtil");
}
protected UnsafeUtil() {}
private static final Object theUnsafe;
private static final Method unsafeCleanBB;
private static volatile boolean hasUnsafeCleanBBError; /** OK to be lazy on thread synchronization, just for early out **/
private static final Method staticFieldOffset;
private static final Method getObjectVolatile;
private static final Method putObjectVolatile;
private static volatile boolean hasGetPutObjectVolatile;
private static final Class<?> illegalAccessLoggerClass;
private static final Long illegalAccessLoggerOffset;
private static final Object illegalAccessLoggerSync = new Object();
private static volatile boolean hasIllegalAccessError;
static {
final Object[] _theUnsafe = { null };
final Method[] _cleanBB = { null };
final Method[] _staticFieldOffset = { null };
final Method[] _objectVolatile = { null, null }; // unsafeGetObjectVolatile, unsafePutObjectVolatile
final Class<?>[] _illegalAccessLoggerClass = { null };
final Long[] _loggerOffset = { null };
AccessController.doPrivileged(new PrivilegedAction<Object>() {
@Override
public Object run() {
Class<?> unsafeClass = null;
try {
// Using: sun.misc.Unsafe { public void invokeCleaner(java.nio.ByteBuffer directBuffer); }
unsafeClass = Class.forName("sun.misc.Unsafe");
{
final Field f = unsafeClass.getDeclaredField("theUnsafe");
f.setAccessible(true);
_theUnsafe[0] = f.get(null);
}
_cleanBB[0] = unsafeClass.getMethod("invokeCleaner", java.nio.ByteBuffer.class);
_cleanBB[0].setAccessible(true);
} catch(final Throwable t) {
if( DEBUG ) {
ExceptionUtils.dumpThrowable("UnsafeUtil", t);
}
}
if( null != _theUnsafe[0] && PlatformPropsImpl.JAVA_9 ) {
try {
_staticFieldOffset[0] = unsafeClass.getDeclaredMethod("staticFieldOffset", Field.class);
_objectVolatile[0] = unsafeClass.getDeclaredMethod("getObjectVolatile", Object.class, long.class);
_objectVolatile[1] = unsafeClass.getDeclaredMethod("putObjectVolatile", Object.class, long.class, Object.class);
if( PlatformPropsImpl.JAVA_9 ) {
_illegalAccessLoggerClass[0] = Class.forName("jdk.internal.module.IllegalAccessLogger");
final Field loggerField = _illegalAccessLoggerClass[0].getDeclaredField("logger");
_loggerOffset[0] = (Long) _staticFieldOffset[0].invoke(_theUnsafe[0], loggerField);
}
} catch(final Throwable t) {
if( DEBUG ) {
ExceptionUtils.dumpThrowable("UnsafeUtil", t);
}
}
}
return null;
} } );
theUnsafe = _theUnsafe[0];
unsafeCleanBB = _cleanBB[0];
hasUnsafeCleanBBError = null == theUnsafe || null == unsafeCleanBB;
if( DEBUG ) {
System.err.println("UnsafeUtil.init: hasTheUnsafe: "+(null!=theUnsafe)+", hasInvokeCleaner: "+!hasUnsafeCleanBBError);
}
staticFieldOffset = _staticFieldOffset[0];
getObjectVolatile = _objectVolatile[0];
putObjectVolatile = _objectVolatile[1];
hasGetPutObjectVolatile = null != staticFieldOffset && null != getObjectVolatile && null != putObjectVolatile;
illegalAccessLoggerClass = _illegalAccessLoggerClass[0];
illegalAccessLoggerOffset = _loggerOffset[0];
hasIllegalAccessError = !hasGetPutObjectVolatile || null == illegalAccessLoggerClass || null == illegalAccessLoggerOffset;
if( DEBUG ) {
System.err.println("UnsafeUtil.init: hasUnsafeGetPutObjectVolatile: "+hasGetPutObjectVolatile+", hasUnsafeIllegalAccessLogger: "+!hasIllegalAccessError);
}
}
/**
* Returns {@code true} if {@code sun.misc.Unsafe.invokeCleaner(java.nio.ByteBuffer)}
* is available and has not caused an exception.
* @see #invokeCleaner(ByteBuffer)
*/
public static boolean hasInvokeCleaner() { return !hasUnsafeCleanBBError; }
/**
* Access to {@code sun.misc.Unsafe.invokeCleaner(java.nio.ByteBuffer)}.
* <p>
* If {@code b} is an direct NIO buffer, i.e {@link sun.nio.ch.DirectBuffer},
* calls it's {@link sun.misc.Cleaner} instance {@code clean()} method once.
* </p>
* @return {@code true} if successful, otherwise {@code false}.
* @see #hasInvokeCleaner()
*/
public static boolean invokeCleaner(final ByteBuffer bb) {
if( hasUnsafeCleanBBError || !bb.isDirect() ) {
return false;
}
try {
unsafeCleanBB.invoke(theUnsafe, bb);
return true;
} catch(final Throwable t) {
hasUnsafeCleanBBError = true;
if( DEBUG ) {
ExceptionUtils.dumpThrowable("UnsafeUtil", t);
}
return false;
}
}
/**
* Returns {@code true} if access to {@code jdk.internal.module.IllegalAcessLogger}'s {@code logger} field
* is available and has not caused an exception.
* @see #doWithoutIllegalAccessLogger(PrivilegedAction)
*/
public static boolean hasIllegalAccessLoggerAccess() { return !hasIllegalAccessError; }
/**
* Issue the given user {@code action} while {@code jdk.internal.module.IllegalAcessLogger}'s {@code logger} has been temporarily disabled.
* <p>
* The caller shall place this call into their own {@link AccessController#doPrivileged(PrivilegedAction)} block.
* </p>
* <p>
* In case the runtime is not {@link PlatformPropsImpl#JAVA_9} or the logger is not accessible or disabling caused an exception,
* the user {@code action} is just executed w/o temporary logger modifications.
* </p>
* @param action the user action task
* @throws RuntimeException is thrown for a caught {@link Throwable} while executing the user {@code action}
* @see #hasIllegalAccessLoggerAccess()
*/
public static <T> T doWithoutIllegalAccessLogger(final PrivilegedAction<T> action) throws RuntimeException {
if( !hasIllegalAccessError ) {
synchronized(illegalAccessLoggerSync) {
final Object newLogger = null;
Object oldLogger = null;
try {
oldLogger = getObjectVolatile.invoke(theUnsafe, illegalAccessLoggerClass, illegalAccessLoggerOffset);
putObjectVolatile.invoke(theUnsafe, illegalAccessLoggerClass, illegalAccessLoggerOffset, newLogger);
} catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
// unaccessible ..
hasIllegalAccessError = true;
if( DEBUG ) {
ExceptionUtils.dumpThrowable("UnsafeUtil", e);
}
return action.run();
}
try {
return action.run();
} catch (final Throwable t) {
if( DEBUG ) {
t.printStackTrace();
}
throw new RuntimeException(t);
} finally {
try {
putObjectVolatile.invoke(theUnsafe, illegalAccessLoggerClass, illegalAccessLoggerOffset, oldLogger);
} catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
// should not happen, worked above @ logger setup
hasIllegalAccessError = true;
throw new InternalError(e);
}
}
}
} else {
return action.run();
}
}
}
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