kylixs commented on code in PR #561: URL: https://github.com/apache/skywalking-java/pull/561#discussion_r1240617968
########## apm-sniffer/bytebuddy-patch/src/test/java/org/apache/skywalking/apm/agent/bytebuddy/SWClassFileLocator.java: ########## @@ -0,0 +1,174 @@ +/* + * 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.skywalking.apm.agent.bytebuddy; + +import net.bytebuddy.dynamic.ClassFileLocator; +import org.apache.skywalking.apm.agent.core.logging.api.ILog; +import org.apache.skywalking.apm.agent.core.logging.api.LogManager; + +import java.io.IOException; +import java.lang.instrument.Instrumentation; +import java.util.concurrent.BlockingQueue; +import java.util.concurrent.CompletableFuture; +import java.util.concurrent.LinkedBlockingDeque; +import java.util.concurrent.TimeUnit; + +/** + * Resolve auxiliary type from Instrumentation.getAllLoadedClasses(). + * Get class bytecode from separate thread to bypass jdk limitation or bug: https://github.com/raphw/byte-buddy/issues/1434 + */ +public class SWClassFileLocator implements ClassFileLocator { + private static ILog LOGGER = LogManager.getLogger(SWClassFileLocator.class); + + private final ForInstrumentation.ClassLoadingDelegate classLoadingDelegate; + private Instrumentation instrumentation; + private ClassLoader classLoader; + private String[] typeNameTraits = {"auxiliary$", "ByteBuddy$", "sw$"}; + private BlockingQueue<ResolutionFutureTask> queue = new LinkedBlockingDeque<>(); + private Thread thread; + private int timeoutSeconds = 2; + private volatile boolean closed; + + public SWClassFileLocator(Instrumentation instrumentation, ClassLoader classLoader) { + this.instrumentation = instrumentation; + this.classLoader = classLoader; + classLoadingDelegate = ForInstrumentation.ClassLoadingDelegate.ForDelegatingClassLoader.of(classLoader); + + // Use thread instead of ExecutorService here, avoiding conflicts with apm-jdk-threadpool-plugin + thread = new Thread(() -> { + while (!closed) { + try { + ResolutionFutureTask task = queue.poll(5, TimeUnit.SECONDS); + if (task != null) { + try { + Resolution resolution = getResolution(task.getClassName()); + task.getFuture().complete(resolution); + } catch (Throwable e) { + task.getFuture().completeExceptionally(e); + } + } + } catch (InterruptedException e) { + // ignore interrupted error + } catch (Throwable e) { + LOGGER.error(e, "Resolve bytecode of class failure"); + } + } + }, "SWClassFileLocator"); + thread.setDaemon(true); + thread.start(); + } + + @Override + public Resolution locate(String name) throws IOException { + if (!match(name)) { + return new Resolution.Illegal(name); + } + if (closed) { + throw new IOException("resolve class failure: closed"); + } + // get class binary representation in a clean thread, avoiding nest calling transformer! + ResolutionFutureTask futureTask = new ResolutionFutureTask(name); + queue.offer(futureTask); + try { + return futureTask.getFuture().get(timeoutSeconds, TimeUnit.SECONDS); + } catch (Exception e) { + throw new IOException("resolve class failure: " + name, e); + } + } + + private boolean match(String name) { + boolean matched = false; + for (String typeNameTrait : typeNameTraits) { + if (name.contains(typeNameTrait)) { + matched = true; + break; + } + } + return matched; + } + + private Resolution getResolution(String name) throws Exception { + SWExtractionClassFileTransformer classFileTransformer = new SWExtractionClassFileTransformer(name); + try { + instrumentation.addTransformer(classFileTransformer, true); + Class aClass = locateClass(name); + if (aClass == null) { + return new Resolution.Illegal(name); + } + instrumentation.retransformClasses(new Class[]{aClass}); + } finally { + instrumentation.removeTransformer(classFileTransformer); + } + + return classFileTransformer.getBinaryRepresentation() != null ? + new Resolution.Explicit(classFileTransformer.getBinaryRepresentation()) : + new Resolution.Illegal(name); + } + + private Class locateClass(String className) { + // find class in classloader + try { + return classLoadingDelegate.locate(className); + } catch (ClassNotFoundException e) { + } + + // find class in instrumentation + Class[] allLoadedClasses = instrumentation.getAllLoadedClasses(); + for (int i = 0; i < allLoadedClasses.length; i++) { + Class aClass = allLoadedClasses[i]; + if (className.equals(aClass.getName())) { + return aClass; + } + } + return null; + } + + @Override + public void close() throws IOException { + closed = true; + queue.clear(); + thread.interrupt(); + } + + public int getTimeoutSeconds() { + return timeoutSeconds; + } + + public void setTimeoutSeconds(int timeoutSeconds) { + this.timeoutSeconds = timeoutSeconds; + } Review Comment: It's used to config resolve timeout, not every public method need a usage, might need it somewhere later. -- This is an automated message from the Apache Git Service. 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