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authorSven Gothel <[email protected]>2019-09-04 04:08:06 +0200
committerSven Gothel <[email protected]>2019-09-04 04:08:06 +0200
commit07c1885e9a3d1f3a3853414648c06fb3864bc69f (patch)
tree05d3dc6707694aef3056db666aec7488835a6ae5 /src/java/com/jogamp/common/util/UnsafeUtil.java
parent252ab21e6b6958cb54992d68535cdb7563b70f40 (diff)
Bug 1363: Java 11: Extract and extend sun.misc.Unsafe functionality to UnsafeUtiljava11ios
UnsafeUtil centralizes the workarounds (hack) of certain Java>=9 modularization encapsulation pitfalls, where no exports have been defined. The last resort. 1) Buffers utilizes UnsafeUtil for Java>=9 invokeCleaner. 2) To gain access for certain methods + fields w/o 'illegal access warnings', we have to temporarily disable the IllegalAccessLogger. Hence we provide a method 'T doWithoutIllegalAccessLogger(..<T> action)' for our essential module access under Java >= 9.
Diffstat (limited to 'src/java/com/jogamp/common/util/UnsafeUtil.java')
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1 files changed, 222 insertions, 0 deletions
diff --git a/src/java/com/jogamp/common/util/UnsafeUtil.java b/src/java/com/jogamp/common/util/UnsafeUtil.java
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+++ b/src/java/com/jogamp/common/util/UnsafeUtil.java
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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();
+ }
+ }
+}