com.taobao.arthas.agent334.AgentBootstrap Maven / Gradle / Ivy
package com.taobao.arthas.agent334;
import java.arthas.SpyAPI;
import java.io.File;
import java.io.FileOutputStream;
import java.io.PrintStream;
import java.io.UnsupportedEncodingException;
import java.lang.instrument.Instrumentation;
import java.net.URL;
import java.net.URLDecoder;
import java.security.CodeSource;
import com.taobao.arthas.agent.ArthasClassloader;
/**
* 代理启动类
*
* @author vlinux on 15/5/19.
*/
public class AgentBootstrap {
private static final String ARTHAS_CORE_JAR = "arthas-core.jar";
private static final String ARTHAS_BOOTSTRAP = "com.taobao.arthas.core.server.ArthasBootstrap";
private static final String GET_INSTANCE = "getInstance";
private static final String IS_BIND = "isBind";
private static PrintStream ps = System.err;
static {
try {
File arthasLogDir = new File(System.getProperty("user.home") + File.separator + "logs" + File.separator
+ "arthas" + File.separator);
if (!arthasLogDir.exists()) {
arthasLogDir.mkdirs();
}
if (!arthasLogDir.exists()) {
// #572
arthasLogDir = new File(System.getProperty("java.io.tmpdir") + File.separator + "logs" + File.separator
+ "arthas" + File.separator);
if (!arthasLogDir.exists()) {
arthasLogDir.mkdirs();
}
}
File log = new File(arthasLogDir, "arthas.log");
if (!log.exists()) {
log.createNewFile();
}
ps = new PrintStream(new FileOutputStream(log, true));
} catch (Throwable t) {
t.printStackTrace(ps);
}
}
/**
*
* 1. 全局持有classloader用于隔离 Arthas 实现，防止多次attach重复初始化
* 2. ClassLoader在arthas停止时会被reset
* 3. 如果ClassLoader一直没变，则 com.taobao.arthas.core.server.ArthasBootstrap#getInstance 返回结果一直是一样的
*
*/
private static volatile ClassLoader arthasClassLoader;
public static void premain(String args, Instrumentation inst) {
main(args, inst);
}
public static void agentmain(String args, Instrumentation inst) {
main(args, inst);
}
/**
* 让下次再次启动时有机会重新加载
*/
public static void resetArthasClassLoader() {
arthasClassLoader = null;
}
private static ClassLoader getClassLoader(Instrumentation inst, File arthasCoreJarFile) throws Throwable {
// 构造自定义的类加载器，尽量减少Arthas对现有工程的侵蚀
return loadOrDefineClassLoader(arthasCoreJarFile);
}
private static ClassLoader loadOrDefineClassLoader(File arthasCoreJarFile) throws Throwable {
if (arthasClassLoader == null) {
arthasClassLoader = new ArthasClassloader(new URL[]{arthasCoreJarFile.toURI().toURL()});
}
return arthasClassLoader;
}
private static synchronized void main(String args, final Instrumentation inst) {
// 尝试判断arthas是否已在运行，如果是的话，直接就退出
try {
Class.forName("java.arthas.SpyAPI"); // 加载不到会抛异常
if (SpyAPI.isInited()) {
ps.println("Arthas server already stared, skip attach.");
ps.flush();
return;
}
} catch (Throwable e) {
// ignore
}
try {
ps.println("Arthas server agent start...");
// 传递的args参数分两个部分:arthasCoreJar路径和agentArgs, 分别是Agent的JAR包路径和期望传递到服务端的参数
if (args == null) {
args = "";
}
args = decodeArg(args);
String arthasCoreJar;
final String agentArgs;
int index = args.indexOf(';');
if (index != -1) {
arthasCoreJar = args.substring(0, index);
agentArgs = args.substring(index);
} else {
arthasCoreJar = "";
agentArgs = args;
}
File arthasCoreJarFile = new File(arthasCoreJar);
if (!arthasCoreJarFile.exists()) {
ps.println("Can not find arthas-core jar file from args: " + arthasCoreJarFile);
// try to find from arthas-agent.jar directory
CodeSource codeSource = AgentBootstrap.class.getProtectionDomain().getCodeSource();
if (codeSource != null) {
try {
File arthasAgentJarFile = new File(codeSource.getLocation().toURI().getSchemeSpecificPart());
arthasCoreJarFile = new File(arthasAgentJarFile.getParentFile(), ARTHAS_CORE_JAR);
if (!arthasCoreJarFile.exists()) {
ps.println("Can not find arthas-core jar file from agent jar directory: " + arthasAgentJarFile);
}
} catch (Throwable e) {
ps.println("Can not find arthas-core jar file from " + codeSource.getLocation());
e.printStackTrace(ps);
}
}
}
if (!arthasCoreJarFile.exists()) {
return;
}
/**
* Use a dedicated thread to run the binding logic to prevent possible memory leak. #195
*/
final ClassLoader agentLoader = getClassLoader(inst, arthasCoreJarFile);
Thread bindingThread = new Thread() {
@Override
public void run() {
try {
bind(inst, agentLoader, agentArgs);
} catch (Throwable throwable) {
throwable.printStackTrace(ps);
}
}
};
bindingThread.setName("arthas-binding-thread");
bindingThread.start();
bindingThread.join();
} catch (Throwable t) {
t.printStackTrace(ps);
try {
if (ps != System.err) {
ps.close();
}
} catch (Throwable tt) {
// ignore
}
throw new RuntimeException(t);
}
}
private static void bind(Instrumentation inst, ClassLoader agentLoader, String args) throws Throwable {
/**
*
* ArthasBootstrap bootstrap = ArthasBootstrap.getInstance(inst);
*
*/
Class bootstrapClass = agentLoader.loadClass(ARTHAS_BOOTSTRAP);
Object bootstrap = bootstrapClass.getMethod(GET_INSTANCE, Instrumentation.class, String.class).invoke(null, inst, args);
boolean isBind = (Boolean) bootstrapClass.getMethod(IS_BIND).invoke(bootstrap);
if (!isBind) {
String errorMsg = "Arthas server port binding failed! Please check $HOME/logs/arthas/arthas.log for more details.";
ps.println(errorMsg);
throw new RuntimeException(errorMsg);
}
ps.println("Arthas server already bind.");
}
private static String decodeArg(String arg) {
try {
return URLDecoder.decode(arg, "utf-8");
} catch (UnsupportedEncodingException e) {
return arg;
}
}
}