jdk-sandbox: comparison src/java.base/share/classes/java/lang/Shutdown.java

equal deleted inserted replaced

-:4f11514fe783
+:a6c4b85163c1
 /*
-* Copyright (c) 1999, 2005, Oracle and/or its affiliates. All rights reserved.
+* Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 */
 package java.lang;
+import jdk.internal.misc.VM;
 /**
 * Package-private utility class containing data structures and logic
 * governing the virtual-machine shutdown sequence.
 *
 * @author   Mark Reinhold
 * @since    1.3
+*
+* @see java.io.Console
+* @see ApplicationShutdownHooks
+* @see java.io.DeleteOnExitHook
 */
 class Shutdown {
-/* Shutdown state */
-private static final int RUNNING = 0;
-private static final int HOOKS = 1;
-private static final int FINALIZERS = 2;
-private static int state = RUNNING;
-/* Should we run all finalizers upon exit? */
-private static boolean runFinalizersOnExit = false;
 // The system shutdown hooks are registered with a predefined slot.
 // The list of shutdown hooks is as follows:
 // (0) Console restore hook
-// (1) Application hooks
+// (1) ApplicationShutdownHooks that invokes all registered application
+//     shutdown hooks and waits until they finish
 // (2) DeleteOnExit hook
 private static final int MAX_SYSTEM_HOOKS = 10;
 private static final Runnable[] hooks = new Runnable[MAX_SYSTEM_HOOKS];
 // the index of the currently running shutdown hook to the hooks array
-private static int currentRunningHook = 0;
+private static int currentRunningHook = -1;
 /* The preceding static fields are protected by this lock */
 private static class Lock { };
 private static Object lock = new Lock();
 /* Lock object for the native halt method */
 private static Object haltLock = new Lock();
-/* Invoked by Runtime.runFinalizersOnExit */
-static void setRunFinalizersOnExit(boolean run) {
-synchronized (lock) {
-runFinalizersOnExit = run;
-}
-}
 /**
-* Add a new shutdown hook.  Checks the shutdown state and the hook itself,
+* Add a new system shutdown hook.  Checks the shutdown state and
-* but does not do any security checks.
+* the hook itself, but does not do any security checks.
 *
 * The registerShutdownInProgress parameter should be false except
 * registering the DeleteOnExitHook since the first file may
 * be added to the delete on exit list by the application shutdown
 * hooks.
 *         if registerShutdownInProgress is false and shutdown is in progress; or
 *         if registerShutdownInProgress is true and the shutdown process
 *         already passes the given slot
 */
 static void add(int slot, boolean registerShutdownInProgress, Runnable hook) {
+if (slot < 0 || slot >= MAX_SYSTEM_HOOKS) {
+throw new IllegalArgumentException("Invalid slot: " + slot);
+}
 synchronized (lock) {
 if (hooks[slot] != null)
 throw new InternalError("Shutdown hook at slot " + slot + " already registered");
 if (!registerShutdownInProgress) {
-if (state > RUNNING)
+if (currentRunningHook >= 0)
 throw new IllegalStateException("Shutdown in progress");
 } else {
-if (state > HOOKS || (state == HOOKS && slot <= currentRunningHook))
+if (VM.isShutdown() || slot <= currentRunningHook)
 throw new IllegalStateException("Shutdown in progress");
 }
 hooks[slot] = hook;
 }
 }
-/* Run all registered shutdown hooks
+/* Run all system shutdown hooks.
+*
+* The system shutdown hooks are run in the thread synchronized on
+* Shutdown.class.  Other threads calling Runtime::exit, Runtime::halt
+* or JNI DestroyJavaVM will block indefinitely.
+*
+* ApplicationShutdownHooks is registered as one single hook that starts
+* all application shutdown hooks and waits until they finish.
 */
 private static void runHooks() {
+synchronized (lock) {
+/* Guard against the possibility of a daemon thread invoking exit
+* after DestroyJavaVM initiates the shutdown sequence
+*/
+if (VM.isShutdown()) return;
+}
 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) {
+} catch (Throwable t) {
 if (t instanceof ThreadDeath) {
 ThreadDeath td = (ThreadDeath)t;
 throw td;
 }
 }
 }
+// set shutdown state
+VM.shutdown();
 }
 /* The halt method is synchronized on the halt lock
 * to avoid corruption of the delete-on-shutdown file list.
 * It invokes the true native halt method.
 }
 }
 static native void halt0(int status);
-/* Wormhole for invoking java.lang.ref.Finalizer.runAllFinalizers */
-private static native void runAllFinalizers();
-/* The actual shutdown sequence is defined here.
-*
-* If it weren't for runFinalizersOnExit, this would be simple -- we'd just
-* run the hooks and then halt.  Instead we need to keep track of whether
-* we're running hooks or finalizers.  In the latter case a finalizer could
-* invoke exit(1) to cause immediate termination, while in the former case
-* any further invocations of exit(n), for any n, simply stall.  Note that
-* if on-exit finalizers are enabled they're run iff the shutdown is
-* initiated by an exit(0); they're never run on exit(n) for n != 0 or in
-* response to SIGINT, SIGTERM, etc.
-*/
-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();
-}
 /* Invoked by Runtime.exit, which does all the security checks.
 * Also invoked by handlers for system-provided termination events,
 * which should pass a nonzero status code.
 */
 static void exit(int status) {
-boolean runMoreFinalizers = false;
 synchronized (lock) {
-if (status != 0) runFinalizersOnExit = false;
+if (status != 0 && VM.isShutdown()) {
-switch (state) {
+/* Halt immediately on nonzero status */
-case RUNNING:       /* Initiate shutdown */
+halt(status);
-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();
+runHooks();
 halt(status);
 }
 }
 /* Invoked by the JNI DestroyJavaVM procedure when the last non-daemon
 * thread has finished.  Unlike the exit method, this method does not
 * actually halt the VM.
 */
 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();
+runHooks();
 }
 }
 }

changeset 48942	a6c4b85163c1
parent 47216	71c04702a3d5
child 49186	b8bfadfacded