vlambda博客
学习文章列表

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) { ; }
 } }}

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(); } }}

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();}

#启用shutdownendpoints.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IPmanagement.port=8088management.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