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8187443: Forest Consolidation: Move files to unified layout
Reviewed-by: darcy, ihse
This commit is contained in:
Erik Joelsson
parent
270fe13182
commit
3789983e89
56923 changed files with 3 additions and 15727 deletions
993
src/java.base/share/classes/java/lang/StackStreamFactory.java
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993
src/java.base/share/classes/java/lang/StackStreamFactory.java
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@ -0,0 +1,993 @@
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/*
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* Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation. Oracle designates this
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* particular file as subject to the "Classpath" exception as provided
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* by Oracle in the LICENSE file that accompanied this code.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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package java.lang;
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import jdk.internal.reflect.MethodAccessor;
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import jdk.internal.reflect.ConstructorAccessor;
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import java.lang.StackWalker.Option;
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import java.lang.StackWalker.StackFrame;
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import java.lang.annotation.Native;
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import java.lang.reflect.Method;
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import java.lang.reflect.Constructor;
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import java.util.HashSet;
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import java.util.NoSuchElementException;
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import java.util.Objects;
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import java.util.Set;
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import java.util.Spliterator;
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import java.util.function.Consumer;
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import java.util.function.Function;
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import java.util.stream.Stream;
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import java.util.stream.StreamSupport;
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import sun.security.action.GetPropertyAction;
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import static java.lang.StackStreamFactory.WalkerState.*;
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/**
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* StackStreamFactory class provides static factory methods
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* to get different kinds of stack walker/traverser.
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*
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* AbstractStackWalker provides the basic stack walking support
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* fetching stack frames from VM in batches.
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*
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* AbstractStackWalker subclass is specialized for a specific kind of stack traversal
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* to avoid overhead of Stream/Lambda
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* 1. Support traversing Stream<StackFrame>
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* 2. StackWalker::getCallerClass
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* 3. AccessControlContext getting ProtectionDomain
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*/
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final class StackStreamFactory {
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private StackStreamFactory() {}
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// Stack walk implementation classes to be excluded during stack walking
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// lazily add subclasses when they are loaded.
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private final static Set<Class<?>> stackWalkImplClasses = init();
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private static final int SMALL_BATCH = 8;
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private static final int BATCH_SIZE = 32;
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private static final int LARGE_BATCH_SIZE = 256;
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private static final int MIN_BATCH_SIZE = SMALL_BATCH;
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// These flags must match the values maintained in the VM
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@Native private static final int DEFAULT_MODE = 0x0;
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@Native private static final int FILL_CLASS_REFS_ONLY = 0x2;
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@Native private static final int GET_CALLER_CLASS = 0x4;
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@Native private static final int SHOW_HIDDEN_FRAMES = 0x20; // LambdaForms are hidden by the VM
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@Native private static final int FILL_LIVE_STACK_FRAMES = 0x100;
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/*
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* For Throwable to use StackWalker, set useNewThrowable to true.
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* Performance work and extensive testing is needed to replace the
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* VM built-in backtrace filled in Throwable with the StackWalker.
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*/
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final static boolean isDebug =
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"true".equals(GetPropertyAction.privilegedGetProperty("stackwalk.debug"));
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static <T> StackFrameTraverser<T>
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makeStackTraverser(StackWalker walker, Function<? super Stream<StackFrame>, ? extends T> function)
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{
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if (walker.hasLocalsOperandsOption())
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return new LiveStackInfoTraverser<>(walker, function);
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else
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return new StackFrameTraverser<>(walker, function);
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}
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/**
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* Gets a stack stream to find caller class.
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*/
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static CallerClassFinder makeCallerFinder(StackWalker walker) {
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return new CallerClassFinder(walker);
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}
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enum WalkerState {
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NEW, // the stream is new and stack walking has not started
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OPEN, // the stream is open when it is being traversed.
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CLOSED; // the stream is closed when the stack walking is done
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}
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/**
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* Subclass of AbstractStackWalker implements a specific stack walking logic.
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* It needs to set up the frame buffer and stack walking mode.
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*
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* It initiates the VM stack walking via the callStackWalk method that serves
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* as the anchored frame and VM will call up to AbstractStackWalker::doStackWalk.
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*
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* @param <R> the type of the result returned from stack walking
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* @param <T> the type of the data gathered for each frame.
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* For example, StackFrameInfo for StackWalker::walk or
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* Class<?> for StackWalker::getCallerClass
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*/
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static abstract class AbstractStackWalker<R, T> {
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protected final StackWalker walker;
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protected final Thread thread;
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protected final int maxDepth;
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protected final long mode;
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protected int depth; // traversed stack depth
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protected FrameBuffer<? extends T> frameBuffer;
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protected long anchor;
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// buffers to fill in stack frame information
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protected AbstractStackWalker(StackWalker walker, int mode) {
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this(walker, mode, Integer.MAX_VALUE);
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}
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protected AbstractStackWalker(StackWalker walker, int mode, int maxDepth) {
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this.thread = Thread.currentThread();
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this.mode = toStackWalkMode(walker, mode);
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this.walker = walker;
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this.maxDepth = maxDepth;
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this.depth = 0;
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}
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private int toStackWalkMode(StackWalker walker, int mode) {
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int newMode = mode;
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if (walker.hasOption(Option.SHOW_HIDDEN_FRAMES) &&
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(mode & FILL_CLASS_REFS_ONLY) != FILL_CLASS_REFS_ONLY)
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newMode |= SHOW_HIDDEN_FRAMES;
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if (walker.hasLocalsOperandsOption())
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newMode |= FILL_LIVE_STACK_FRAMES;
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return newMode;
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}
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/**
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* A callback method to consume the stack frames. This method is invoked
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* once stack walking begins (i.e. it is only invoked when walkFrames is called).
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*
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* Each specialized AbstractStackWalker subclass implements the consumeFrames method
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* to control the following:
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* 1. fetch the subsequent batches of stack frames
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* 2. reuse or expand the allocated buffers
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* 3. create specialized StackFrame objects
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*
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* @return the number of consumed frames
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*/
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protected abstract R consumeFrames();
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/**
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* Initialize FrameBuffer. Subclass should implement this method to
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* create its custom frame buffers.
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*/
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protected abstract void initFrameBuffer();
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/**
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* Returns the suggested next batch size.
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*
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* Subclass should override this method to change the batch size
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*
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* @param lastBatchFrameCount number of frames in the last batch; or zero
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* @return suggested batch size
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*/
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protected abstract int batchSize(int lastBatchFrameCount);
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/*
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* Returns the next batch size, always >= minimum batch size (32)
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*
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* Subclass may override this method if the minimum batch size is different.
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*/
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protected int getNextBatchSize() {
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int lastBatchSize = depth == 0 ? 0 : frameBuffer.curBatchFrameCount();
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int nextBatchSize = batchSize(lastBatchSize);
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if (isDebug) {
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System.err.println("last batch size = " + lastBatchSize +
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" next batch size = " + nextBatchSize);
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}
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return nextBatchSize >= MIN_BATCH_SIZE ? nextBatchSize : MIN_BATCH_SIZE;
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}
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/*
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* Checks if this stream is in the given state. Otherwise, throws IllegalStateException.
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*
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* VM also validates this stream if it's anchored for stack walking
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* when stack frames are fetched for each batch.
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*/
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final void checkState(WalkerState state) {
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if (thread != Thread.currentThread()) {
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throw new IllegalStateException("Invalid thread walking this stack stream: " +
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Thread.currentThread().getName() + " " + thread.getName());
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}
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switch (state) {
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case NEW:
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if (anchor != 0) {
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throw new IllegalStateException("This stack stream is being reused.");
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}
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break;
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case OPEN:
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if (anchor == 0 || anchor == -1L) {
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throw new IllegalStateException("This stack stream is not valid for walking.");
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}
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break;
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case CLOSED:
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if (anchor != -1L) {
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throw new IllegalStateException("This stack stream is not closed.");
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}
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}
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}
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/*
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* Close this stream. This stream becomes invalid to walk.
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*/
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private void close() {
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this.anchor = -1L;
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}
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/*
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* Walks stack frames until {@link #consumeFrames} is done consuming
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* the frames it is interested in.
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*/
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final R walk() {
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checkState(NEW);
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try {
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// VM will need to stablize the stack before walking. It will invoke
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// the AbstractStackWalker::doStackWalk method once it fetches the first batch.
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// the callback will be invoked within the scope of the callStackWalk frame.
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return beginStackWalk();
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} finally {
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close(); // done traversal; close the stream
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}
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}
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private boolean skipReflectionFrames() {
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return !walker.hasOption(Option.SHOW_REFLECT_FRAMES) &&
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!walker.hasOption(Option.SHOW_HIDDEN_FRAMES);
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}
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/*
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* Returns {@code Class} object at the current frame;
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* or {@code null} if no more frame. If advanceToNextBatch is true,
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* it will only fetch the next batch.
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*/
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final Class<?> peekFrame() {
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while (frameBuffer.isActive() && depth < maxDepth) {
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if (frameBuffer.isEmpty()) {
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// fetch another batch of stack frames
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getNextBatch();
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} else {
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Class<?> c = frameBuffer.get();
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if (skipReflectionFrames() && isReflectionFrame(c)) {
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if (isDebug)
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System.err.println(" skip: frame " + frameBuffer.getIndex() + " " + c);
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frameBuffer.next();
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depth++;
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continue;
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} else {
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return c;
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}
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}
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}
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return null;
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}
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/*
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* This method is only invoked by VM.
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*
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* It will invoke the consumeFrames method to start the stack walking
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* with the first batch of stack frames. Each specialized AbstractStackWalker
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* subclass implements the consumeFrames method to control the following:
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* 1. fetch the subsequent batches of stack frames
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* 2. reuse or expand the allocated buffers
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* 3. create specialized StackFrame objects
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*/
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private Object doStackWalk(long anchor, int skipFrames, int batchSize,
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int bufStartIndex, int bufEndIndex) {
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checkState(NEW);
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frameBuffer.check(skipFrames);
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if (isDebug) {
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System.err.format("doStackWalk: skip %d start %d end %d%n",
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skipFrames, bufStartIndex, bufEndIndex);
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}
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this.anchor = anchor; // set anchor for this bulk stack frame traversal
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frameBuffer.setBatch(depth, bufStartIndex, bufEndIndex);
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// traverse all frames and perform the action on the stack frames, if specified
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return consumeFrames();
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}
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/*
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* Get next batch of stack frames.
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*/
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private int getNextBatch() {
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int nextBatchSize = Math.min(maxDepth - depth, getNextBatchSize());
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if (!frameBuffer.isActive() || nextBatchSize <= 0) {
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if (isDebug) {
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System.out.format(" more stack walk done%n");
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}
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frameBuffer.freeze(); // stack walk done
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return 0;
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}
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return fetchStackFrames(nextBatchSize);
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}
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/*
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* This method traverses the next stack frame and returns the Class
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* invoking that stack frame.
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*
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* This method can only be called during the walk method. This is intended
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* to be used to walk the stack frames in one single invocation and
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* this stack stream will be invalidated once walk is done.
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*
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* @see #tryNextFrame
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*/
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final Class<?> nextFrame() {
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if (!hasNext()) {
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return null;
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}
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Class<?> c = frameBuffer.next();
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depth++;
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return c;
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}
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/*
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* Returns true if there is next frame to be traversed.
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* This skips hidden frames unless this StackWalker has
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* {@link Option#SHOW_REFLECT_FRAMES}
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*/
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final boolean hasNext() {
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return peekFrame() != null;
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}
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/**
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* Begin stack walking - pass the allocated arrays to the VM to fill in
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* stack frame information.
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*
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* VM first anchors the frame of the current thread. A traversable stream
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* on this thread's stack will be opened. The VM will fetch the first batch
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* of stack frames and call AbstractStackWalker::doStackWalk to invoke the
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* stack walking function on each stack frame.
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*
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* If all fetched stack frames are traversed, AbstractStackWalker::fetchStackFrames will
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* fetch the next batch of stack frames to continue.
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*/
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private R beginStackWalk() {
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// initialize buffers for VM to fill the stack frame info
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initFrameBuffer();
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return callStackWalk(mode, 0,
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frameBuffer.curBatchFrameCount(),
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frameBuffer.startIndex(),
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frameBuffer.frames());
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}
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/*
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* Fetches stack frames.
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*
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* @params batchSize number of elements of the frame buffers for this batch
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* @returns number of frames fetched in this batch
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*/
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private int fetchStackFrames(int batchSize) {
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int startIndex = frameBuffer.startIndex();
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frameBuffer.resize(startIndex, batchSize);
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int endIndex = fetchStackFrames(mode, anchor, batchSize,
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startIndex,
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frameBuffer.frames());
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if (isDebug) {
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System.out.format(" more stack walk requesting %d got %d to %d frames%n",
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batchSize, frameBuffer.startIndex(), endIndex);
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}
|
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int numFrames = endIndex - startIndex;
|
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if (numFrames == 0) {
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frameBuffer.freeze(); // done stack walking
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} else {
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frameBuffer.setBatch(depth, startIndex, endIndex);
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}
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return numFrames;
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}
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|
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/**
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* Begins stack walking. This method anchors this frame and invokes
|
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* AbstractStackWalker::doStackWalk after fetching the first batch of stack frames.
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*
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* @param mode mode of stack walking
|
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* @param skipframes number of frames to be skipped before filling the frame buffer.
|
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* @param batchSize the batch size, max. number of elements to be filled in the frame buffers.
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* @param startIndex start index of the frame buffers to be filled.
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* @param frames Either a Class<?> array, if mode is {@link #FILL_CLASS_REFS_ONLY}
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* or a {@link StackFrameInfo} (or derivative) array otherwise.
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* @return Result of AbstractStackWalker::doStackWalk
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*/
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private native R callStackWalk(long mode, int skipframes,
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int batchSize, int startIndex,
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T[] frames);
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||||
|
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/**
|
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* Fetch the next batch of stack frames.
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||||
*
|
||||
* @param mode mode of stack walking
|
||||
* @param anchor
|
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* @param batchSize the batch size, max. number of elements to be filled in the frame buffers.
|
||||
* @param startIndex start index of the frame buffers to be filled.
|
||||
* @param frames Either a Class<?> array, if mode is {@link #FILL_CLASS_REFS_ONLY}
|
||||
* or a {@link StackFrameInfo} (or derivative) array otherwise.
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||||
*
|
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* @return the end index to the frame buffers
|
||||
*/
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||||
private native int fetchStackFrames(long mode, long anchor,
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int batchSize, int startIndex,
|
||||
T[] frames);
|
||||
}
|
||||
|
||||
/*
|
||||
* This StackFrameTraverser supports {@link Stream} traversal.
|
||||
*
|
||||
* This class implements Spliterator::forEachRemaining and Spliterator::tryAdvance.
|
||||
*/
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static class StackFrameTraverser<T> extends AbstractStackWalker<T, StackFrameInfo>
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implements Spliterator<StackFrame>
|
||||
{
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||||
static {
|
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stackWalkImplClasses.add(StackFrameTraverser.class);
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||||
}
|
||||
private static final int CHARACTERISTICS = Spliterator.ORDERED | Spliterator.IMMUTABLE;
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||||
|
||||
final class StackFrameBuffer extends FrameBuffer<StackFrameInfo> {
|
||||
private StackFrameInfo[] stackFrames;
|
||||
StackFrameBuffer(int initialBatchSize) {
|
||||
super(initialBatchSize);
|
||||
|
||||
this.stackFrames = new StackFrameInfo[initialBatchSize];
|
||||
for (int i = START_POS; i < initialBatchSize; i++) {
|
||||
stackFrames[i] = new StackFrameInfo(walker);
|
||||
}
|
||||
}
|
||||
|
||||
@Override
|
||||
StackFrameInfo[] frames() {
|
||||
return stackFrames;
|
||||
}
|
||||
|
||||
@Override
|
||||
void resize(int startIndex, int elements) {
|
||||
if (!isActive())
|
||||
throw new IllegalStateException("inactive frame buffer can't be resized");
|
||||
|
||||
assert startIndex == START_POS :
|
||||
"bad start index " + startIndex + " expected " + START_POS;
|
||||
|
||||
int size = startIndex+elements;
|
||||
if (stackFrames.length < size) {
|
||||
StackFrameInfo[] newFrames = new StackFrameInfo[size];
|
||||
// copy initial magic...
|
||||
System.arraycopy(stackFrames, 0, newFrames, 0, startIndex);
|
||||
stackFrames = newFrames;
|
||||
}
|
||||
for (int i = startIndex; i < size; i++) {
|
||||
stackFrames[i] = new StackFrameInfo(walker);
|
||||
}
|
||||
currentBatchSize = size;
|
||||
}
|
||||
|
||||
@Override
|
||||
StackFrameInfo nextStackFrame() {
|
||||
if (isEmpty()) {
|
||||
throw new NoSuchElementException("origin=" + origin + " fence=" + fence);
|
||||
}
|
||||
|
||||
StackFrameInfo frame = stackFrames[origin];
|
||||
origin++;
|
||||
return frame;
|
||||
}
|
||||
|
||||
@Override
|
||||
final Class<?> at(int index) {
|
||||
return stackFrames[index].declaringClass();
|
||||
}
|
||||
}
|
||||
|
||||
final Function<? super Stream<StackFrame>, ? extends T> function; // callback
|
||||
|
||||
StackFrameTraverser(StackWalker walker,
|
||||
Function<? super Stream<StackFrame>, ? extends T> function) {
|
||||
this(walker, function, DEFAULT_MODE);
|
||||
}
|
||||
StackFrameTraverser(StackWalker walker,
|
||||
Function<? super Stream<StackFrame>, ? extends T> function,
|
||||
int mode) {
|
||||
super(walker, mode);
|
||||
this.function = function;
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns next StackFrame object in the current batch of stack frames;
|
||||
* or null if no more stack frame.
|
||||
*/
|
||||
StackFrame nextStackFrame() {
|
||||
if (!hasNext()) {
|
||||
return null;
|
||||
}
|
||||
|
||||
StackFrameInfo frame = frameBuffer.nextStackFrame();
|
||||
depth++;
|
||||
return frame;
|
||||
}
|
||||
|
||||
@Override
|
||||
protected T consumeFrames() {
|
||||
checkState(OPEN);
|
||||
Stream<StackFrame> stream = StreamSupport.stream(this, false);
|
||||
if (function != null) {
|
||||
return function.apply(stream);
|
||||
} else
|
||||
throw new UnsupportedOperationException();
|
||||
}
|
||||
|
||||
@Override
|
||||
protected void initFrameBuffer() {
|
||||
this.frameBuffer = new StackFrameBuffer(getNextBatchSize());
|
||||
}
|
||||
|
||||
@Override
|
||||
protected int batchSize(int lastBatchFrameCount) {
|
||||
if (lastBatchFrameCount == 0) {
|
||||
// First batch, use estimateDepth if not exceed the large batch size
|
||||
// and not too small
|
||||
int initialBatchSize = Math.max(walker.estimateDepth(), SMALL_BATCH);
|
||||
return Math.min(initialBatchSize, LARGE_BATCH_SIZE);
|
||||
} else {
|
||||
if (lastBatchFrameCount > BATCH_SIZE) {
|
||||
return lastBatchFrameCount;
|
||||
} else {
|
||||
return Math.min(lastBatchFrameCount*2, BATCH_SIZE);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// ------- Implementation of Spliterator
|
||||
|
||||
@Override
|
||||
public Spliterator<StackFrame> trySplit() {
|
||||
return null; // ordered stream and do not allow to split
|
||||
}
|
||||
|
||||
@Override
|
||||
public long estimateSize() {
|
||||
return maxDepth;
|
||||
}
|
||||
|
||||
@Override
|
||||
public int characteristics() {
|
||||
return CHARACTERISTICS;
|
||||
}
|
||||
|
||||
@Override
|
||||
public void forEachRemaining(Consumer<? super StackFrame> action) {
|
||||
checkState(OPEN);
|
||||
for (int n = 0; n < maxDepth; n++) {
|
||||
StackFrame frame = nextStackFrame();
|
||||
if (frame == null) break;
|
||||
|
||||
action.accept(frame);
|
||||
}
|
||||
}
|
||||
|
||||
@Override
|
||||
public boolean tryAdvance(Consumer<? super StackFrame> action) {
|
||||
checkState(OPEN);
|
||||
|
||||
int index = frameBuffer.getIndex();
|
||||
if (hasNext()) {
|
||||
StackFrame frame = nextStackFrame();
|
||||
action.accept(frame);
|
||||
if (isDebug) {
|
||||
System.err.println("tryAdvance: " + index + " " + frame);
|
||||
}
|
||||
return true;
|
||||
}
|
||||
if (isDebug) {
|
||||
System.err.println("tryAdvance: " + index + " NO element");
|
||||
}
|
||||
return false;
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* CallerClassFinder is specialized to return Class<?> for each stack frame.
|
||||
* StackFrame is not requested.
|
||||
*/
|
||||
static final class CallerClassFinder extends AbstractStackWalker<Integer, Class<?>> {
|
||||
static {
|
||||
stackWalkImplClasses.add(CallerClassFinder.class);
|
||||
}
|
||||
|
||||
private Class<?> caller;
|
||||
|
||||
CallerClassFinder(StackWalker walker) {
|
||||
super(walker, FILL_CLASS_REFS_ONLY|GET_CALLER_CLASS);
|
||||
}
|
||||
|
||||
final class ClassBuffer extends FrameBuffer<Class<?>> {
|
||||
Class<?>[] classes; // caller class for fast path
|
||||
ClassBuffer(int batchSize) {
|
||||
super(batchSize);
|
||||
classes = new Class<?>[batchSize];
|
||||
}
|
||||
|
||||
@Override
|
||||
Class<?>[] frames() { return classes;}
|
||||
|
||||
@Override
|
||||
final Class<?> at(int index) { return classes[index];}
|
||||
|
||||
|
||||
// ------ subclass may override the following methods -------
|
||||
/**
|
||||
* Resizes the buffers for VM to fill in the next batch of stack frames.
|
||||
* The next batch will start at the given startIndex with the maximum number
|
||||
* of elements.
|
||||
*
|
||||
* <p> Subclass may override this method to manage the allocated buffers.
|
||||
*
|
||||
* @param startIndex the start index for the first frame of the next batch to fill in.
|
||||
* @param elements the number of elements for the next batch to fill in.
|
||||
*
|
||||
*/
|
||||
@Override
|
||||
void resize(int startIndex, int elements) {
|
||||
if (!isActive())
|
||||
throw new IllegalStateException("inactive frame buffer can't be resized");
|
||||
|
||||
assert startIndex == START_POS :
|
||||
"bad start index " + startIndex + " expected " + START_POS;
|
||||
|
||||
int size = startIndex+elements;
|
||||
if (classes.length < size) {
|
||||
// copy the elements in classes array to the newly allocated one.
|
||||
// classes[0] is a Thread object
|
||||
Class<?>[] prev = classes;
|
||||
classes = new Class<?>[size];
|
||||
System.arraycopy(prev, 0, classes, 0, startIndex);
|
||||
}
|
||||
currentBatchSize = size;
|
||||
}
|
||||
}
|
||||
|
||||
Class<?> findCaller() {
|
||||
walk();
|
||||
return caller;
|
||||
}
|
||||
|
||||
@Override
|
||||
protected Integer consumeFrames() {
|
||||
checkState(OPEN);
|
||||
int n = 0;
|
||||
Class<?>[] frames = new Class<?>[2];
|
||||
// skip the API calling this getCallerClass method
|
||||
// 0: StackWalker::getCallerClass
|
||||
// 1: caller-sensitive method
|
||||
// 2: caller class
|
||||
while (n < 2 && (caller = nextFrame()) != null) {
|
||||
if (isMethodHandleFrame(caller)) { continue; }
|
||||
if (isReflectionFrame(caller)) { continue; }
|
||||
frames[n++] = caller;
|
||||
}
|
||||
if (frames[1] == null) {
|
||||
throw new IllegalCallerException("no caller frame");
|
||||
}
|
||||
return n;
|
||||
}
|
||||
|
||||
@Override
|
||||
protected void initFrameBuffer() {
|
||||
this.frameBuffer = new ClassBuffer(getNextBatchSize());
|
||||
}
|
||||
|
||||
@Override
|
||||
protected int batchSize(int lastBatchFrameCount) {
|
||||
return MIN_BATCH_SIZE;
|
||||
}
|
||||
|
||||
@Override
|
||||
protected int getNextBatchSize() {
|
||||
return MIN_BATCH_SIZE;
|
||||
}
|
||||
}
|
||||
|
||||
static final class LiveStackInfoTraverser<T> extends StackFrameTraverser<T> {
|
||||
static {
|
||||
stackWalkImplClasses.add(LiveStackInfoTraverser.class);
|
||||
}
|
||||
// VM will fill in all method info and live stack info directly in StackFrameInfo
|
||||
final class LiveStackFrameBuffer extends FrameBuffer<LiveStackFrameInfo> {
|
||||
private LiveStackFrameInfo[] stackFrames;
|
||||
LiveStackFrameBuffer(int initialBatchSize) {
|
||||
super(initialBatchSize);
|
||||
this.stackFrames = new LiveStackFrameInfo[initialBatchSize];
|
||||
for (int i = START_POS; i < initialBatchSize; i++) {
|
||||
stackFrames[i] = new LiveStackFrameInfo(walker);
|
||||
}
|
||||
}
|
||||
|
||||
@Override
|
||||
LiveStackFrameInfo[] frames() {
|
||||
return stackFrames;
|
||||
}
|
||||
|
||||
@Override
|
||||
void resize(int startIndex, int elements) {
|
||||
if (!isActive()) {
|
||||
throw new IllegalStateException("inactive frame buffer can't be resized");
|
||||
}
|
||||
assert startIndex == START_POS :
|
||||
"bad start index " + startIndex + " expected " + START_POS;
|
||||
|
||||
int size = startIndex + elements;
|
||||
if (stackFrames.length < size) {
|
||||
LiveStackFrameInfo[] newFrames = new LiveStackFrameInfo[size];
|
||||
// copy initial magic...
|
||||
System.arraycopy(stackFrames, 0, newFrames, 0, startIndex);
|
||||
stackFrames = newFrames;
|
||||
}
|
||||
|
||||
for (int i = startIndex(); i < size; i++) {
|
||||
stackFrames[i] = new LiveStackFrameInfo(walker);
|
||||
}
|
||||
|
||||
currentBatchSize = size;
|
||||
}
|
||||
|
||||
@Override
|
||||
LiveStackFrameInfo nextStackFrame() {
|
||||
if (isEmpty()) {
|
||||
throw new NoSuchElementException("origin=" + origin + " fence=" + fence);
|
||||
}
|
||||
|
||||
LiveStackFrameInfo frame = stackFrames[origin];
|
||||
origin++;
|
||||
return frame;
|
||||
}
|
||||
|
||||
@Override
|
||||
final Class<?> at(int index) {
|
||||
return stackFrames[index].declaringClass();
|
||||
}
|
||||
}
|
||||
|
||||
LiveStackInfoTraverser(StackWalker walker,
|
||||
Function<? super Stream<StackFrame>, ? extends T> function) {
|
||||
super(walker, function, DEFAULT_MODE);
|
||||
}
|
||||
|
||||
@Override
|
||||
protected void initFrameBuffer() {
|
||||
this.frameBuffer = new LiveStackFrameBuffer(getNextBatchSize());
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* Frame buffer
|
||||
*
|
||||
* Each specialized AbstractStackWalker subclass may subclass the FrameBuffer.
|
||||
*/
|
||||
static abstract class FrameBuffer<F> {
|
||||
static final int START_POS = 2; // 0th and 1st elements are reserved
|
||||
|
||||
// buffers for VM to fill stack frame info
|
||||
int currentBatchSize; // current batch size
|
||||
int origin; // index to the current traversed stack frame
|
||||
int fence; // index to the last frame in the current batch
|
||||
|
||||
FrameBuffer(int initialBatchSize) {
|
||||
if (initialBatchSize < MIN_BATCH_SIZE) {
|
||||
throw new IllegalArgumentException(initialBatchSize +
|
||||
" < minimum batch size: " + MIN_BATCH_SIZE);
|
||||
}
|
||||
this.origin = START_POS;
|
||||
this.fence = 0;
|
||||
this.currentBatchSize = initialBatchSize;
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns an array of frames that may be used to store frame objects
|
||||
* when walking the stack.
|
||||
*
|
||||
* May be an array of {@code Class<?>} if the {@code AbstractStackWalker}
|
||||
* mode is {@link #FILL_CLASS_REFS_ONLY}, or an array of
|
||||
* {@link StackFrameInfo} (or derivative) array otherwise.
|
||||
*
|
||||
* @return An array of frames that may be used to store frame objects
|
||||
* when walking the stack. Must not be null.
|
||||
*/
|
||||
abstract F[] frames(); // must not return null
|
||||
|
||||
/**
|
||||
* Resizes the buffers for VM to fill in the next batch of stack frames.
|
||||
* The next batch will start at the given startIndex with the maximum number
|
||||
* of elements.
|
||||
*
|
||||
* <p> Subclass may override this method to manage the allocated buffers.
|
||||
*
|
||||
* @param startIndex the start index for the first frame of the next batch to fill in.
|
||||
* @param elements the number of elements for the next batch to fill in.
|
||||
*
|
||||
*/
|
||||
abstract void resize(int startIndex, int elements);
|
||||
|
||||
/**
|
||||
* Return the class at the given position in the current batch.
|
||||
* @param index the position of the frame.
|
||||
* @return the class at the given position in the current batch.
|
||||
*/
|
||||
abstract Class<?> at(int index);
|
||||
|
||||
// ------ subclass may override the following methods -------
|
||||
|
||||
/*
|
||||
* Returns the start index for this frame buffer is refilled.
|
||||
*
|
||||
* This implementation reuses the allocated buffer for the next batch
|
||||
* of stack frames. For subclass to retain the fetched stack frames,
|
||||
* it should override this method to return the index at which the frame
|
||||
* should be filled in for the next batch.
|
||||
*/
|
||||
int startIndex() {
|
||||
return START_POS;
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns next StackFrame object in the current batch of stack frames
|
||||
*/
|
||||
F nextStackFrame() {
|
||||
throw new InternalError("should not reach here");
|
||||
}
|
||||
|
||||
// ------ FrameBuffer implementation ------
|
||||
|
||||
final int curBatchFrameCount() {
|
||||
return currentBatchSize-START_POS;
|
||||
}
|
||||
|
||||
/*
|
||||
* Tests if this frame buffer is empty. All frames are fetched.
|
||||
*/
|
||||
final boolean isEmpty() {
|
||||
return origin >= fence || (origin == START_POS && fence == 0);
|
||||
}
|
||||
|
||||
/*
|
||||
* Freezes this frame buffer. The stack stream source is done fetching.
|
||||
*/
|
||||
final void freeze() {
|
||||
origin = 0;
|
||||
fence = 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* Tests if this frame buffer is active. It is inactive when
|
||||
* it is done for traversal. All stack frames have been traversed.
|
||||
*/
|
||||
final boolean isActive() {
|
||||
return origin > 0 && (fence == 0 || origin < fence || fence == currentBatchSize);
|
||||
}
|
||||
|
||||
/**
|
||||
* Gets the class at the current frame and move to the next frame.
|
||||
*/
|
||||
final Class<?> next() {
|
||||
if (isEmpty()) {
|
||||
throw new NoSuchElementException("origin=" + origin + " fence=" + fence);
|
||||
}
|
||||
Class<?> c = at(origin);
|
||||
origin++;
|
||||
if (isDebug) {
|
||||
int index = origin-1;
|
||||
System.out.format(" next frame at %d: %s (origin %d fence %d)%n", index,
|
||||
Objects.toString(c), index, fence);
|
||||
}
|
||||
return c;
|
||||
}
|
||||
|
||||
/**
|
||||
* Gets the class at the current frame.
|
||||
*/
|
||||
final Class<?> get() {
|
||||
if (isEmpty()) {
|
||||
throw new NoSuchElementException("origin=" + origin + " fence=" + fence);
|
||||
}
|
||||
return at(origin);
|
||||
}
|
||||
|
||||
/*
|
||||
* Returns the index of the current frame.
|
||||
*/
|
||||
final int getIndex() {
|
||||
return origin;
|
||||
}
|
||||
|
||||
/*
|
||||
* Set the start and end index of a new batch of stack frames that have
|
||||
* been filled in this frame buffer.
|
||||
*/
|
||||
final void setBatch(int depth, int startIndex, int endIndex) {
|
||||
if (startIndex <= 0 || endIndex <= 0)
|
||||
throw new IllegalArgumentException("startIndex=" + startIndex
|
||||
+ " endIndex=" + endIndex);
|
||||
|
||||
this.origin = startIndex;
|
||||
this.fence = endIndex;
|
||||
if (depth == 0 && fence > 0) {
|
||||
// filter the frames due to the stack stream implementation
|
||||
for (int i = START_POS; i < fence; i++) {
|
||||
Class<?> c = at(i);
|
||||
if (isDebug) System.err.format(" frame %d: %s%n", i, c);
|
||||
if (filterStackWalkImpl(c)) {
|
||||
origin++;
|
||||
} else {
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* Checks if the origin is the expected start index.
|
||||
*/
|
||||
final void check(int skipFrames) {
|
||||
int index = skipFrames + START_POS;
|
||||
if (origin != index) {
|
||||
// stack walk must continue with the previous frame depth
|
||||
throw new IllegalStateException("origin " + origin + " != " + index);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
private static native boolean checkStackWalkModes();
|
||||
|
||||
// avoid loading other subclasses as they may not be used
|
||||
private static Set<Class<?>> init() {
|
||||
if (!checkStackWalkModes()) {
|
||||
throw new InternalError("StackWalker mode values do not match with JVM");
|
||||
}
|
||||
|
||||
Set<Class<?>> classes = new HashSet<>();
|
||||
classes.add(StackWalker.class);
|
||||
classes.add(StackStreamFactory.class);
|
||||
classes.add(AbstractStackWalker.class);
|
||||
return classes;
|
||||
}
|
||||
|
||||
private static boolean filterStackWalkImpl(Class<?> c) {
|
||||
return stackWalkImplClasses.contains(c) ||
|
||||
c.getName().startsWith("java.util.stream.");
|
||||
}
|
||||
|
||||
// MethodHandle frames are not hidden and CallerClassFinder has
|
||||
// to filter them out
|
||||
private static boolean isMethodHandleFrame(Class<?> c) {
|
||||
return c.getName().startsWith("java.lang.invoke.");
|
||||
}
|
||||
|
||||
private static boolean isReflectionFrame(Class<?> c) {
|
||||
// ## should filter all @Hidden frames?
|
||||
return c == Method.class ||
|
||||
c == Constructor.class ||
|
||||
MethodAccessor.class.isAssignableFrom(c) ||
|
||||
ConstructorAccessor.class.isAssignableFrom(c) ||
|
||||
c.getName().startsWith("java.lang.invoke.LambdaForm");
|
||||
}
|
||||
|
||||
}
|
||||
Loading…
Add table
Add a link
Reference in a new issue