| /* ==================================================================== |
| Licensed to the Apache Software Foundation (ASF) under one or more |
| contributor license agreements. See the NOTICE file distributed with |
| this work for additional information regarding copyright ownership. |
| The ASF licenses this file to You 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. |
| ==================================================================== */ |
| |
| package org.apache.poi.poifs.nio; |
| |
| import org.apache.poi.util.SuppressForbidden; |
| |
| import java.io.IOException; |
| import java.lang.invoke.MethodHandle; |
| import java.lang.invoke.MethodHandles; |
| import java.lang.reflect.Field; |
| import java.lang.reflect.Method; |
| import java.nio.ByteBuffer; |
| import java.security.AccessController; |
| import java.security.PrivilegedAction; |
| import java.util.Objects; |
| |
| import static java.lang.invoke.MethodHandles.constant; |
| import static java.lang.invoke.MethodHandles.dropArguments; |
| import static java.lang.invoke.MethodHandles.filterReturnValue; |
| import static java.lang.invoke.MethodHandles.guardWithTest; |
| import static java.lang.invoke.MethodType.methodType; |
| |
| /** |
| * This is taken from Hadoop at https://issues.apache.org/jira/browse/HADOOP-12760 and |
| * https://github.com/apache/hadoop/blob/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/CleanerUtil.java |
| * Unfortunately this is not available in some general utility library yet, but hopefully will be at some point. |
| * |
| * sun.misc.Cleaner has moved in OpenJDK 9 and |
| * sun.misc.Unsafe#invokeCleaner(ByteBuffer) is the replacement. |
| * This class is a hack to use sun.misc.Cleaner in Java 8 and |
| * use the replacement in Java 9+. |
| * This implementation is inspired by LUCENE-6989. |
| */ |
| public final class CleanerUtil { |
| |
| // Prevent instantiation |
| private CleanerUtil(){} |
| |
| /** |
| * <code>true</code>, if this platform supports unmapping mmapped files. |
| */ |
| public static final boolean UNMAP_SUPPORTED; |
| |
| /** |
| * if {@link #UNMAP_SUPPORTED} is {@code false}, this contains the reason |
| * why unmapping is not supported. |
| */ |
| public static final String UNMAP_NOT_SUPPORTED_REASON; |
| |
| |
| private static final BufferCleaner CLEANER; |
| |
| /** |
| * Reference to a BufferCleaner that does unmapping. |
| * @return {@code null} if not supported. |
| */ |
| public static BufferCleaner getCleaner() { |
| return CLEANER; |
| } |
| |
| static { |
| final Object hack = AccessController.doPrivileged( |
| (PrivilegedAction<Object>) CleanerUtil::unmapHackImpl); |
| if (hack instanceof BufferCleaner) { |
| CLEANER = (BufferCleaner) hack; |
| UNMAP_SUPPORTED = true; |
| UNMAP_NOT_SUPPORTED_REASON = null; |
| } else { |
| CLEANER = null; |
| UNMAP_SUPPORTED = false; |
| UNMAP_NOT_SUPPORTED_REASON = hack.toString(); |
| } |
| } |
| |
| @SuppressForbidden("Java 9 Jigsaw allows access to sun.misc.Cleaner, so setAccessible works") |
| private static Object unmapHackImpl() { |
| final MethodHandles.Lookup lookup = MethodHandles.lookup(); |
| try { |
| try { |
| // *** sun.misc.Unsafe unmapping (Java 9+) *** |
| final Class<?> unsafeClass = Class.forName("sun.misc.Unsafe"); |
| // first check if Unsafe has the right method, otherwise we can |
| // give up without doing any security critical stuff: |
| final MethodHandle unmapper = lookup.findVirtual(unsafeClass, |
| "invokeCleaner", methodType(void.class, ByteBuffer.class)); |
| // fetch the unsafe instance and bind it to the virtual MH: |
| final Field f = unsafeClass.getDeclaredField("theUnsafe"); |
| f.setAccessible(true); |
| final Object theUnsafe = f.get(null); |
| return newBufferCleaner(ByteBuffer.class, unmapper.bindTo(theUnsafe)); |
| } catch (SecurityException se) { |
| // rethrow to report errors correctly (we need to catch it here, |
| // as we also catch RuntimeException below!): |
| throw se; |
| } catch (ReflectiveOperationException | RuntimeException e) { |
| // *** sun.misc.Cleaner unmapping (Java 8) *** |
| final Class<?> directBufferClass = |
| Class.forName("java.nio.DirectByteBuffer"); |
| |
| final Method m = directBufferClass.getMethod("cleaner"); |
| m.setAccessible(true); |
| final MethodHandle directBufferCleanerMethod = lookup.unreflect(m); |
| final Class<?> cleanerClass = |
| directBufferCleanerMethod.type().returnType(); |
| |
| /* |
| * "Compile" a MethodHandle that basically is equivalent |
| * to the following code: |
| * |
| * void unmapper(ByteBuffer byteBuffer) { |
| * sun.misc.Cleaner cleaner = |
| * ((java.nio.DirectByteBuffer) byteBuffer).cleaner(); |
| * if (Objects.nonNull(cleaner)) { |
| * cleaner.clean(); |
| * } else { |
| * // the noop is needed because MethodHandles#guardWithTest |
| * // always needs ELSE |
| * noop(cleaner); |
| * } |
| * } |
| */ |
| final MethodHandle cleanMethod = lookup.findVirtual( |
| cleanerClass, "clean", methodType(void.class)); |
| final MethodHandle nonNullTest = lookup.findStatic(Objects.class, |
| "nonNull", methodType(boolean.class, Object.class)) |
| .asType(methodType(boolean.class, cleanerClass)); |
| final MethodHandle noop = dropArguments( |
| constant(Void.class, null).asType(methodType(void.class)), |
| 0, cleanerClass); |
| final MethodHandle unmapper = filterReturnValue( |
| directBufferCleanerMethod, |
| guardWithTest(nonNullTest, cleanMethod, noop)) |
| .asType(methodType(void.class, ByteBuffer.class)); |
| return newBufferCleaner(directBufferClass, unmapper); |
| } |
| } catch (SecurityException se) { |
| return "Unmapping is not supported, because not all required " + |
| "permissions are given to the Hadoop JAR file: " + se + |
| " [Please grant at least the following permissions: " + |
| "RuntimePermission(\"accessClassInPackage.sun.misc\") " + |
| " and ReflectPermission(\"suppressAccessChecks\")]"; |
| } catch (ReflectiveOperationException | RuntimeException e) { |
| return "Unmapping is not supported on this platform, " + |
| "because internal Java APIs are not compatible with " + |
| "this Hadoop version: " + e; |
| } |
| } |
| |
| private static BufferCleaner newBufferCleaner( |
| final Class<?> unmappableBufferClass, final MethodHandle unmapper) { |
| assert Objects.equals( |
| methodType(void.class, ByteBuffer.class), unmapper.type()); |
| return buffer -> { |
| if (!buffer.isDirect()) { |
| throw new IllegalArgumentException( |
| "unmapping only works with direct buffers"); |
| } |
| if (!unmappableBufferClass.isInstance(buffer)) { |
| throw new IllegalArgumentException("buffer is not an instance of " + |
| unmappableBufferClass.getName()); |
| } |
| final Throwable error = AccessController.doPrivileged( |
| (PrivilegedAction<Throwable>) () -> { |
| try { |
| unmapper.invokeExact(buffer); |
| return null; |
| } catch (Throwable t) { |
| return t; |
| } |
| }); |
| if (error != null) { |
| throw new IOException("Unable to unmap the mapped buffer", error); |
| } |
| }; |
| } |
| |
| /** |
| * Pass in an implementation of this interface to cleanup ByteBuffers. |
| * CleanerUtil implements this to allow unmapping of bytebuffers |
| * with private Java APIs. |
| */ |
| @FunctionalInterface |
| public interface BufferCleaner { |
| void freeBuffer(ByteBuffer b) throws IOException; |
| } |
| } |