diff --git a/src/java.base/share/classes/jdk/internal/jimage/BasicImageReader.java b/src/java.base/share/classes/jdk/internal/jimage/BasicImageReader.java index 6807928b2c2..10aa0397f0c 100644 --- a/src/java.base/share/classes/jdk/internal/jimage/BasicImageReader.java +++ b/src/java.base/share/classes/jdk/internal/jimage/BasicImageReader.java @@ -1,5 +1,5 @@ /* - * Copyright (c) 2014, 2025, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2014, 2026, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it @@ -220,14 +220,6 @@ public class BasicImageReader implements AutoCloseable { return slice(buffer, offset, size).order(byteOrder).asIntBuffer(); } - public static void releaseByteBuffer(ByteBuffer buffer) { - Objects.requireNonNull(buffer); - - if (!MAP_ALL) { - ImageBufferCache.releaseBuffer(buffer); - } - } - public String getName() { return name; } @@ -362,13 +354,15 @@ public class BasicImageReader implements AutoCloseable { if (offset < 0 || Integer.MAX_VALUE <= offset) { throw new IndexOutOfBoundsException("Bad offset: " + offset); } + int checkedOffset = (int) offset; if (size < 0 || Integer.MAX_VALUE <= size) { - throw new IndexOutOfBoundsException("Bad size: " + size); + throw new IllegalArgumentException("Bad size: " + size); } + int checkedSize = (int) size; if (MAP_ALL) { - ByteBuffer buffer = slice(memoryMap, (int)offset, (int)size); + ByteBuffer buffer = slice(memoryMap, checkedOffset, checkedSize); buffer.order(ByteOrder.BIG_ENDIAN); return buffer; @@ -376,21 +370,18 @@ public class BasicImageReader implements AutoCloseable { if (channel == null) { throw new InternalError("Image file channel not open"); } - - ByteBuffer buffer = ImageBufferCache.getBuffer(size); + ByteBuffer buffer = ByteBuffer.allocate(checkedSize); int read; try { - read = channel.read(buffer, offset); + read = channel.read(buffer, checkedOffset); buffer.rewind(); } catch (IOException ex) { - ImageBufferCache.releaseBuffer(buffer); throw new RuntimeException(ex); } - if (read != size) { - ImageBufferCache.releaseBuffer(buffer); + if (read != checkedSize) { throw new RuntimeException("Short read: " + read + - " instead of " + size + " bytes"); + " instead of " + checkedSize + " bytes"); } return buffer; @@ -406,17 +397,12 @@ public class BasicImageReader implements AutoCloseable { public byte[] getResource(ImageLocation loc) { ByteBuffer buffer = getResourceBuffer(loc); - - if (buffer != null) { - byte[] bytes = getBufferBytes(buffer); - ImageBufferCache.releaseBuffer(buffer); - - return bytes; - } - - return null; + return buffer != null ? getBufferBytes(buffer) : null; } + /** + * Returns the content of jimage location in a newly allocated byte buffer. + */ public ByteBuffer getResourceBuffer(ImageLocation loc) { Objects.requireNonNull(loc); long offset = loc.getContentOffset() + indexSize; @@ -437,10 +423,8 @@ public class BasicImageReader implements AutoCloseable { return readBuffer(offset, uncompressedSize); } else { ByteBuffer buffer = readBuffer(offset, compressedSize); - if (buffer != null) { byte[] bytesIn = getBufferBytes(buffer); - ImageBufferCache.releaseBuffer(buffer); byte[] bytesOut; try { diff --git a/src/java.base/share/classes/jdk/internal/jimage/ImageBufferCache.java b/src/java.base/share/classes/jdk/internal/jimage/ImageBufferCache.java deleted file mode 100644 index c2cc4a028be..00000000000 --- a/src/java.base/share/classes/jdk/internal/jimage/ImageBufferCache.java +++ /dev/null @@ -1,158 +0,0 @@ -/* - * Copyright (c) 2014, 2016, Oracle and/or its affiliates. All rights reserved. - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. - * - * This code is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 only, as - * published by the Free Software Foundation. Oracle designates this - * particular file as subject to the "Classpath" exception as provided - * by Oracle in the LICENSE file that accompanied this code. - * - * This code is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License - * version 2 for more details (a copy is included in the LICENSE file that - * accompanied this code). - * - * You should have received a copy of the GNU General Public License version - * 2 along with this work; if not, write to the Free Software Foundation, - * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. - * - * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA - * or visit www.oracle.com if you need additional information or have any - * questions. - */ -package jdk.internal.jimage; - -import java.lang.ref.WeakReference; -import java.nio.ByteBuffer; -import java.util.AbstractMap; -import java.util.Arrays; -import java.util.Comparator; -import java.util.Map; - -/** - * @implNote This class needs to maintain JDK 8 source compatibility. - * - * It is used internally in the JDK to implement jimage/jrtfs access, - * but also compiled and delivered as part of the jrt-fs.jar to support access - * to the jimage file provided by the shipped JDK by tools running on JDK 8. - */ -class ImageBufferCache { - private static final int MAX_CACHED_BUFFERS = 3; - private static final int LARGE_BUFFER = 0x10000; - - /* - * We used to have a class BufferReference extending from WeakReference. - * BufferReference class had an instance field called "capacity". This field was - * used to make DECREASING_CAPACITY_NULLS_LAST comparator stable in the presence - * of GC clearing the WeakReference concurrently. - * - * But this scheme results in metaspace leak. The thread local is alive till the - * the thread is alive. And so ImageBufferCache$BufferReference class was kept alive. - * Because this class and ImageBufferCache$BufferReference are all loaded by a URL - * class loader from jrt-fs.jar, the class loader and so all the classes loaded by it - * were alive! - * - * Solution is to avoid using a URL loader loaded class type with thread local. All we - * need is a pair of WeakReference, Integer (saved capacity for stability - * of comparator). We use Map.Entry as pair implementation. With this, all types used - * with thread local are bootstrap types and so no metaspace leak. - */ - @SuppressWarnings("unchecked") - private static final ThreadLocal, Integer>[]> CACHE = - new ThreadLocal, Integer>[]>() { - @Override - protected Map.Entry, Integer>[] initialValue() { - // 1 extra slot to simplify logic of releaseBuffer() - return (Map.Entry, Integer>[])new Map.Entry[MAX_CACHED_BUFFERS + 1]; - } - }; - - private static ByteBuffer allocateBuffer(long size) { - return ByteBuffer.allocateDirect((int)((size + 0xFFF) & ~0xFFF)); - } - - static ByteBuffer getBuffer(long size) { - if (size < 0 || Integer.MAX_VALUE < size) { - throw new IndexOutOfBoundsException("size"); - } - - ByteBuffer result = null; - - if (size > LARGE_BUFFER) { - result = allocateBuffer(size); - } else { - Map.Entry, Integer>[] cache = CACHE.get(); - - // buffers are ordered by decreasing capacity - // cache[MAX_CACHED_BUFFERS] is always null - for (int i = MAX_CACHED_BUFFERS - 1; i >= 0; i--) { - Map.Entry, Integer> reference = cache[i]; - - if (reference != null) { - ByteBuffer buffer = getByteBuffer(reference); - - if (buffer != null && size <= buffer.capacity()) { - cache[i] = null; - result = buffer; - result.rewind(); - break; - } - } - } - - if (result == null) { - result = allocateBuffer(size); - } - } - - result.limit((int)size); - - return result; - } - - static void releaseBuffer(ByteBuffer buffer) { - if (buffer.capacity() > LARGE_BUFFER) { - return; - } - - Map.Entry, Integer>[] cache = CACHE.get(); - - // expunge cleared BufferRef(s) - for (int i = 0; i < MAX_CACHED_BUFFERS; i++) { - Map.Entry, Integer> reference = cache[i]; - if (reference != null && getByteBuffer(reference) == null) { - cache[i] = null; - } - } - - // insert buffer back with new BufferRef wrapping it - cache[MAX_CACHED_BUFFERS] = newCacheEntry(buffer); - Arrays.sort(cache, DECREASING_CAPACITY_NULLS_LAST); - // squeeze the smallest one out - cache[MAX_CACHED_BUFFERS] = null; - } - - private static Map.Entry, Integer> newCacheEntry(ByteBuffer bb) { - return new AbstractMap.SimpleEntry, Integer>( - new WeakReference(bb), bb.capacity()); - } - - private static int getCapacity(Map.Entry, Integer> e) { - return e == null? 0 : e.getValue(); - } - - private static ByteBuffer getByteBuffer(Map.Entry, Integer> e) { - return e == null? null : e.getKey().get(); - } - - private static Comparator, Integer>> DECREASING_CAPACITY_NULLS_LAST = - new Comparator, Integer>>() { - @Override - public int compare(Map.Entry, Integer> br1, - Map.Entry, Integer> br2) { - return Integer.compare(getCapacity(br1), getCapacity(br2)); - } - }; -} diff --git a/src/java.base/share/classes/jdk/internal/jimage/ImageReader.java b/src/java.base/share/classes/jdk/internal/jimage/ImageReader.java index e062e1629ff..c36e265ee2f 100644 --- a/src/java.base/share/classes/jdk/internal/jimage/ImageReader.java +++ b/src/java.base/share/classes/jdk/internal/jimage/ImageReader.java @@ -1,5 +1,5 @@ /* - * Copyright (c) 2014, 2025, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2014, 2026, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it @@ -190,20 +190,7 @@ public final class ImageReader implements AutoCloseable { } /** - * Releases a (possibly cached) {@link ByteBuffer} obtained via - * {@link #getResourceBuffer(Node)}. - * - *

Note that no testing is performed to check whether the buffer about - * to be released actually came from a call to {@code getResourceBuffer()}. - */ - public static void releaseByteBuffer(ByteBuffer buffer) { - BasicImageReader.releaseByteBuffer(buffer); - } - - /** - * Returns the content of a resource node in a possibly cached byte buffer. - * Callers of this method must call {@link #releaseByteBuffer(ByteBuffer)} - * when they are finished with it. + * Returns the content of a resource node in a newly allocated byte buffer. */ public ByteBuffer getResourceBuffer(Node node) { requireOpen(); diff --git a/src/java.base/share/classes/jdk/internal/module/SystemModuleFinders.java b/src/java.base/share/classes/jdk/internal/module/SystemModuleFinders.java index 370c151af84..afebb89168c 100644 --- a/src/java.base/share/classes/jdk/internal/module/SystemModuleFinders.java +++ b/src/java.base/share/classes/jdk/internal/module/SystemModuleFinders.java @@ -1,5 +1,5 @@ /* - * Copyright (c) 2015, 2025, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2015, 2026, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it @@ -467,12 +467,6 @@ public final class SystemModuleFinders { .map(reader::getResourceBuffer); } - @Override - public void release(ByteBuffer bb) { - Objects.requireNonNull(bb); - ImageReader.releaseByteBuffer(bb); - } - @Override public Stream list() throws IOException { if (closed)