private static synchronized void main()

in agent/src/main/java/com/taobao/arthas/agent334/AgentBootstrap.java [90:173]
71 lines of code
14 McCabe index (conditional complexity)

    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);
        }
    }