你们的优雅停机真的优雅吗？ - ToB企服应用市场:ToB评测及商务社交产业平台

public interface SignalHandler {
SignalHandler SIG_DFL = new NativeSignalHandler(0L);
SignalHandler SIG_IGN = new NativeSignalHandler(1L);
void handle(Signal var1);
}
class Terminator {
private static SignalHandler handler = null;
Terminator() {
}
//jvm设置SignalHandler，在System.initializeSystemClass中触发
static void setup() {
if (handler == null) {
SignalHandler var0 = new SignalHandler() {
public void handle(Signal var1) {
Shutdown.exit(var1.getNumber() + 128);//调用Shutdown.exit
}
};
handler = var0;
try {
Signal.handle(new Signal("INT"), var0);//中断时
} catch (IllegalArgumentException var3) {
}
try {
Signal.handle(new Signal("TERM"), var0);//终止时
} catch (IllegalArgumentException var2) {
}
}
}
}

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public class Runtime {
public void addShutdownHook(Thread hook) {
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
sm.checkPermission(new RuntimePermission("shutdownHooks"));
}
ApplicationShutdownHooks.add(hook);
}
}
class ApplicationShutdownHooks {
/* The set of registered hooks */
private static IdentityHashMap<Thread, Thread> hooks;
static synchronized void add(Thread hook) {
if(hooks == null)
throw new IllegalStateException("Shutdown in progress");
if (hook.isAlive())
throw new IllegalArgumentException("Hook already running");
if (hooks.containsKey(hook))
throw new IllegalArgumentException("Hook previously registered");
hooks.put(hook, hook);
}
}
//它含数据结构和逻辑管理虚拟机关闭序列
class Shutdown {
/* Shutdown 系列状态*/
private static final int RUNNING = 0;
private static final int HOOKS = 1;
private static final int FINALIZERS = 2;
private static int state = RUNNING;
/* 是否应该运行所以finalizers来exit? */
private static boolean runFinalizersOnExit = false;
// 系统关闭钩子注册一个预定义的插槽.
// 关闭钩子的列表如下:
// (0) Console restore hook
// (1) Application hooks
// (2) DeleteOnExit hook
private static final int MAX_SYSTEM_HOOKS = 10;
private static final Runnable[] hooks = new Runnable[MAX_SYSTEM_HOOKS];
// 当前运行关闭钩子的钩子的索引
private static int currentRunningHook = 0;
/* 前面的静态字段由这个锁保护 */
private static class Lock { };
private static Object lock = new Lock();
/* 为native halt方法提供锁对象 */
private static Object haltLock = new Lock();
static void add(int slot, boolean registerShutdownInProgress, Runnable hook) {
synchronized (lock) {
if (hooks[slot] != null)
throw new InternalError("Shutdown hook at slot " + slot + " already registered");
if (!registerShutdownInProgress) {//执行shutdown过程中不添加hook
if (state > RUNNING)//如果已经在执行shutdown操作不能添加hook
throw new IllegalStateException("Shutdown in progress");
} else {//如果hooks已经执行完毕不能再添加hook。如果正在执行hooks时，添加的槽点小于当前执行的槽点位置也不能添加
if (state > HOOKS || (state == HOOKS && slot <= currentRunningHook))
throw new IllegalStateException("Shutdown in progress");
}
hooks[slot] = hook;
}
}
/* 执行所有注册的hooks
*/
private static void runHooks() {
for (int i=0; i < MAX_SYSTEM_HOOKS; i++) {
try {
Runnable hook;
synchronized (lock) {
// acquire the lock to make sure the hook registered during
// shutdown is visible here.
currentRunningHook = i;
hook = hooks[i];
}
if (hook != null) hook.run();
} catch(Throwable t) {
if (t instanceof ThreadDeath) {
ThreadDeath td = (ThreadDeath)t;
throw td;
}
}
}
}
/* 关闭JVM的操作
*/
static void halt(int status) {
synchronized (haltLock) {
halt0(status);
}
}
//JNI方法
static native void halt0(int status);
// shutdown的执行顺序：runHooks > runFinalizersOnExit
private static void sequence() {
synchronized (lock) {
/* Guard against the possibility of a daemon thread invoking exit
* after DestroyJavaVM initiates the shutdown sequence
*/
if (state != HOOKS) return;
}
runHooks();
boolean rfoe;
synchronized (lock) {
state = FINALIZERS;
rfoe = runFinalizersOnExit;
}
if (rfoe) runAllFinalizers();
}
//Runtime.exit时执行，runHooks > runFinalizersOnExit > halt
static void exit(int status) {
boolean runMoreFinalizers = false;
synchronized (lock) {
if (status != 0) runFinalizersOnExit = false;
switch (state) {
case RUNNING: /* Initiate shutdown */
state = HOOKS;
break;
case HOOKS: /* Stall and halt */
break;
case FINALIZERS:
if (status != 0) {
/* Halt immediately on nonzero status */
halt(status);
} else {
/* Compatibility with old behavior:
* Run more finalizers and then halt
*/
runMoreFinalizers = runFinalizersOnExit;
}
break;
}
}
if (runMoreFinalizers) {
runAllFinalizers();
halt(status);
}
synchronized (Shutdown.class) {
/* Synchronize on the class object, causing any other thread
* that attempts to initiate shutdown to stall indefinitely
*/
sequence();
halt(status);
}
}
//shutdown操作，与exit不同的是不做halt操作(关闭JVM)
static void shutdown() {
synchronized (lock) {
switch (state) {
case RUNNING: /* Initiate shutdown */
state = HOOKS;
break;
case HOOKS: /* Stall and then return */
case FINALIZERS:
break;
}
}
synchronized (Shutdown.class) {
sequence();
}
}
}

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public abstract class AbstractApplicationContext extends DefaultResourceLoader {
public void registerShutdownHook() {
if (this.shutdownHook == null) {
// No shutdown hook registered yet.
this.shutdownHook = new Thread() {
@Override
public void run() {
doClose();
}
};
Runtime.getRuntime().addShutdownHook(this.shutdownHook);
}
}
protected void doClose() {
boolean actuallyClose;
synchronized (this.activeMonitor) {
actuallyClose = this.active && !this.closed;
this.closed = true;
}
if (actuallyClose) {
if (logger.isInfoEnabled()) {
logger.info("Closing " + this);
}
LiveBeansView.unregisterApplicationContext(this);
try {
//发布应用内的关闭事件
publishEvent(new ContextClosedEvent(this));
}
catch (Throwable ex) {
logger.warn("Exception thrown from ApplicationListener handling ContextClosedEvent", ex);
}
// 停止所有的Lifecycle beans.
try {
getLifecycleProcessor().onClose();
}
catch (Throwable ex) {
logger.warn("Exception thrown from LifecycleProcessor on context close", ex);
}
// 销毁spring 的 BeanFactory可能会缓存单例的 Bean.
destroyBeans();
// 关闭当前应用上下文（BeanFactory）
closeBeanFactory();
// 执行子类的关闭逻辑
onClose();
synchronized (this.activeMonitor) {
this.active = false;
}
}
}
}
public interface LifecycleProcessor extends Lifecycle {
/**
* Notification of context refresh, e.g. for auto-starting components.
*/
void onRefresh();
/**
* Notification of context close phase, e.g. for auto-stopping components.
*/
void onClose();
}

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#启用shutdown
endpoints.shutdown.enabled=true
#禁用密码验证
endpoints.shutdown.sensitive=false
#可统一指定所有endpoints的路径
management.context-path=/manage
#指定管理端口和IP
management.port=8088
management.address=127.0.0.1
#开启shutdown的安全验证（spring-security）
endpoints.shutdown.sensitive=true
#验证用户名
security.user.name=admin
#验证密码
security.user.password=secret
#角色
management.security.role=SUPERUSER

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@ConfigurationProperties(
prefix = "endpoints.shutdown"
)
public class ShutdownMvcEndpoint extends EndpointMvcAdapter {
public ShutdownMvcEndpoint(ShutdownEndpoint delegate) {
super(delegate);
}
//post请求
@PostMapping(
produces = {"application/vnd.spring-boot.actuator.v1+json", "application/json"}
)
@ResponseBody
public Object invoke() {
return !this.getDelegate().isEnabled() ? new ResponseEntity(Collections.singletonMap("message", "This endpoint is disabled"), HttpStatus.NOT_FOUND) : super.invoke();
}
}
@ConfigurationProperties(
prefix = "endpoints.shutdown"
)
public class ShutdownEndpoint extends AbstractEndpoint<Map<String, Object>> implements ApplicationContextAware {
private static final Map<String, Object> NO_CONTEXT_MESSAGE = Collections.unmodifiableMap(Collections.singletonMap("message", "No context to shutdown."));
private static final Map<String, Object> SHUTDOWN_MESSAGE = Collections.unmodifiableMap(Collections.singletonMap("message", "Shutting down, bye..."));
private ConfigurableApplicationContext context;
public ShutdownEndpoint() {
super("shutdown", true, false);
}
//执行关闭
public Map<String, Object> invoke() {
if (this.context == null) {
return NO_CONTEXT_MESSAGE;
} else {
boolean var6 = false;
Map var1;
class NamelessClass_1 implements Runnable {
NamelessClass_1() {
}
public void run() {
try {
Thread.sleep(500L);
} catch (InterruptedException var2) {
Thread.currentThread().interrupt();
}
//这个调用的就是AbstractApplicationContext.close
ShutdownEndpoint.this.context.close();
}
}
try {
var6 = true;
var1 = SHUTDOWN_MESSAGE;
var6 = false;
} finally {
if (var6) {
Thread thread = new Thread(new NamelessClass_1());
thread.setContextClassLoader(this.getClass().getClassLoader());
thread.start();
}
}
Thread thread = new Thread(new NamelessClass_1());
thread.setContextClassLoader(this.getClass().getClassLoader());
thread.start();
return var1;
}
}
}

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/**
* @ClassName ShutDownHook
* @Description
* @Date 2022/10/28 17:47
**/
@Component
@Slf4j
public class ShutDownHook {
@Value("${shutdown.waitTime:10}")
private int waitTime;
@Resource
com.jdjr.fmq.client.consumer.MessageConsumer fmqMessageConsumer;
@Resource
com.jd.jmq.client.consumer.MessageConsumer jmqMessageConsumer;
@PreDestroy
public void destroyHook() {
try {
log.info("ShutDownHook destroy");
jmqMessageConsumer.pause();
fmqMessageConsumer.pause();
int i = 0;
while (i < waitTime) {
try {
Thread.sleep(1000);
log.info("距离服务关停还有{}秒", waitTime - i++);
} catch (Throwable e) {
log.error("异常", e);
}
}
} catch (Throwable e) {
log.error("异常", e);
}
}
}

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@Component
@Lazy(value = false)
public class ShutDown implements ApplicationContextAware {
private static Logger logger = LoggerFactory.getLogger(ShutDown.class);
@Value("${shutdown.waitTime:60}")
private int waitTime;
@Resource
com.jdjr.fmq.client.consumer.MessageConsumer fmqMessageConsumer;
@PostConstruct
public void init() {
logger.info("ShutDownHook init");
}
private ApplicationContext applicationContext = null;
@PreDestroy
public void destroyHook() {
try {
logger.info("ShutDownHook destroy");
destroyJsfProvider();
fmqMessageConsumer.pause();
int i = 0;
while (i < waitTime) {
try {
Thread.sleep(1000);
logger.info("距离服务关停还有{}秒", waitTime - i++);
} catch (Throwable e) {
logger.error("异常", e);
}
}
} catch (Throwable e) {
logger.error("异常", e);
}
}
private void destroyJsfProvider() {
logger.info("关闭所有JSF生产者");
if (null != applicationContext) {
String[] providerBeanNames = applicationContext.getBeanNamesForType(ProviderBean.class);
for (String name : providerBeanNames) {
try {
logger.info("尝试关闭JSF生产者" + name);
ProviderBean bean=(ProviderBean)applicationContext.getBean(name);
bean.destroy();
logger.info("关闭JSF生产者" + name + "成功");
} catch (BeanCreationNotAllowedException re){
logger.error("JSF生产者" + name + "未初始化，忽略");
} catch (Exception e) {
logger.error("关闭JSF生产者失败", e);
}
}
}
logger.info("所有JSF生产者已关闭");
}
@Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
this.applicationContext = applicationContext;
((AbstractApplicationContext)applicationContext).registerShutdownHook();
}
}

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<context-param>
<param-name>logbackDisableServletContainerInitializer</param-name>
<param-value>true</param-value>
</context-param>

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