Example usage for java.util.concurrent ThreadPoolExecutor shutdownNow

List of usage examples for java.util.concurrent ThreadPoolExecutor shutdownNow

Introduction

In this page you can find the example usage for java.util.concurrent ThreadPoolExecutor shutdownNow.

Prototype

public List<Runnable> shutdownNow() 

Source Link

Document

Attempts to stop all actively executing tasks, halts the processing of waiting tasks, and returns a list of the tasks that were awaiting execution.

Usage

From source file:org.geoserver.GeoserverInitStartupListener.java

/**
 * This method tries hard to stop all threads and remove all references to classes in GeoServer
 * so that we can avoid permgen leaks on application undeploy.
 * What happes is that, if any JDK class references to one of the classes loaded by the
 * webapp classloader, then the classloader cannot be collected and neither can all the
 * classes loaded by it (since each class keeps a back reference to the classloader that
 * loaded it). The same happens for any residual thread launched by the web app.
 *///w w  w.j a  v a  2 s .co  m
public void contextDestroyed(ServletContextEvent sce) {
    try {
        LOGGER.info("Beginning GeoServer cleanup sequence");

        // the dreaded classloader
        ClassLoader webappClassLoader = getClass().getClassLoader();

        // unload all of the jdbc drivers we have loaded. We need to store them and unregister
        // later to avoid concurrent modification exceptions
        Enumeration<Driver> drivers = DriverManager.getDrivers();
        Set<Driver> driversToUnload = new HashSet<Driver>();
        while (drivers.hasMoreElements()) {
            Driver driver = drivers.nextElement();
            try {
                // the driver class loader can be null if the driver comes from the JDK, such as the 
                // sun.jdbc.odbc.JdbcOdbcDriver
                ClassLoader driverClassLoader = driver.getClass().getClassLoader();
                if (driverClassLoader != null && webappClassLoader.equals(driverClassLoader)) {
                    driversToUnload.add(driver);
                }
            } catch (Throwable t) {
                t.printStackTrace();
            }
        }
        for (Driver driver : driversToUnload) {
            try {
                DriverManager.deregisterDriver(driver);
                LOGGER.info("Unregistered JDBC driver " + driver);
            } catch (Exception e) {
                LOGGER.log(Level.SEVERE, "Could now unload driver " + driver.getClass(), e);
            }
        }
        drivers = DriverManager.getDrivers();
        while (drivers.hasMoreElements()) {
            Driver driver = drivers.nextElement();
        }
        try {
            Class h2Driver = Class.forName("org.h2.Driver");
            Method m = h2Driver.getMethod("unload");
            m.invoke(null);
        } catch (Exception e) {
            LOGGER.log(Level.WARNING, "Failed to unload the H2 driver", e);
        }

        // unload all deferred authority factories so that we get rid of the timer tasks in them
        try {
            disposeAuthorityFactories(ReferencingFactoryFinder.getCoordinateOperationAuthorityFactories(null));
        } catch (Throwable e) {
            LOGGER.log(Level.WARNING, "Error occurred trying to dispose authority factories", e);
        }
        try {
            disposeAuthorityFactories(ReferencingFactoryFinder.getCRSAuthorityFactories(null));
        } catch (Throwable e) {
            LOGGER.log(Level.WARNING, "Error occurred trying to dispose authority factories", e);
        }
        try {
            disposeAuthorityFactories(ReferencingFactoryFinder.getCSAuthorityFactories(null));
        } catch (Throwable e) {
            LOGGER.log(Level.WARNING, "Error occurred trying to dispose authority factories", e);
        }

        // kill the threads created by referencing
        WeakCollectionCleaner.DEFAULT.exit();
        DeferredAuthorityFactory.exit();
        CRS.reset("all");
        LOGGER.info("Shut down GT referencing threads ");
        // reset 
        ReferencingFactoryFinder.reset();
        CommonFactoryFinder.reset();
        DataStoreFinder.reset();
        DataAccessFinder.reset();
        LOGGER.info("Shut down GT  SPI ");

        LOGGER.info("Shut down coverage thread pool ");
        Object o = Hints.getSystemDefault(Hints.EXECUTOR_SERVICE);
        if (o != null && o instanceof ExecutorService) {
            final ThreadPoolExecutor executor = (ThreadPoolExecutor) o;
            try {
                executor.shutdown();
            } finally {
                try {
                    executor.shutdownNow();
                } finally {

                }
            }
        }

        // unload everything that JAI ImageIO can still refer to
        // We need to store them and unregister later to avoid concurrent modification exceptions
        final IIORegistry ioRegistry = IIORegistry.getDefaultInstance();
        Set<IIOServiceProvider> providersToUnload = new HashSet();
        for (Iterator<Class<?>> cats = ioRegistry.getCategories(); cats.hasNext();) {
            Class<?> category = cats.next();
            for (Iterator it = ioRegistry.getServiceProviders(category, false); it.hasNext();) {
                final IIOServiceProvider provider = (IIOServiceProvider) it.next();
                if (webappClassLoader.equals(provider.getClass().getClassLoader())) {
                    providersToUnload.add(provider);
                }
            }
        }
        for (IIOServiceProvider provider : providersToUnload) {
            ioRegistry.deregisterServiceProvider(provider);
            LOGGER.info("Unregistering Image I/O provider " + provider);
        }

        // unload everything that JAI can still refer to
        final OperationRegistry opRegistry = JAI.getDefaultInstance().getOperationRegistry();
        for (String mode : RegistryMode.getModeNames()) {
            for (Iterator descriptors = opRegistry.getDescriptors(mode).iterator(); descriptors != null
                    && descriptors.hasNext();) {
                RegistryElementDescriptor red = (RegistryElementDescriptor) descriptors.next();
                int factoryCount = 0;
                int unregisteredCount = 0;
                // look for all the factories for that operation
                for (Iterator factories = opRegistry.getFactoryIterator(mode, red.getName()); factories != null
                        && factories.hasNext();) {
                    Object factory = factories.next();
                    if (factory == null) {
                        continue;
                    }
                    factoryCount++;
                    if (webappClassLoader.equals(factory.getClass().getClassLoader())) {
                        boolean unregistered = false;
                        // we need to scan against all "products" to unregister the factory
                        Vector orderedProductList = opRegistry.getOrderedProductList(mode, red.getName());
                        if (orderedProductList != null) {
                            for (Iterator products = orderedProductList.iterator(); products != null
                                    && products.hasNext();) {
                                String product = (String) products.next();
                                try {
                                    opRegistry.unregisterFactory(mode, red.getName(), product, factory);
                                    LOGGER.info("Unregistering JAI factory " + factory.getClass());
                                } catch (Throwable t) {
                                    // may fail due to the factory not being registered against that product
                                }
                            }
                        }
                        if (unregistered) {
                            unregisteredCount++;
                        }

                    }
                }

                // if all the factories were unregistered, get rid of the descriptor as well
                if (factoryCount > 0 && unregisteredCount == factoryCount) {
                    opRegistry.unregisterDescriptor(red);
                }
            }
        }

        // flush all javabean introspection caches as this too can keep a webapp classloader from being unloaded
        Introspector.flushCaches();
        LOGGER.info("Cleaned up javabean caches");

        // unload the logging framework
        if (!relinquishLoggingControl)
            LogManager.shutdown();
        LogFactory.release(Thread.currentThread().getContextClassLoader());

        // GeoTools/GeoServer have a lot of finalizers and until they are run the JVM
        // itself wil keepup the class loader...
        try {
            System.gc();
            System.runFinalization();
            System.gc();
            System.runFinalization();
            System.gc();
            System.runFinalization();
        } catch (Throwable t) {
            System.out.println("Failed to perform closing up finalization");
            t.printStackTrace();
        }
    } catch (Throwable t) {
        // if anything goes south during the cleanup procedures I want to know what it is
        t.printStackTrace();
    }
}

From source file:org.hyperic.hq.measurement.agent.server.ScheduleThread.java

/**
 * Shut down the schedule thread.// ww  w  .  j ava  2  s .  c om
 */
void die() {
    shouldDie.set(true);
    for (String s : executors.keySet()) {
        ThreadPoolExecutor executor = executors.get(s);
        List<Runnable> queuedMetrics = executor.shutdownNow();
        log.info("Shut down executor service for plugin '" + s + "'" + " with " + queuedMetrics.size()
                + " queued collections");
    }

    metricLoggingTask.cancel(true);
    metricVerificationTask.cancel(true);
    List<Runnable> pending = metricVerificationService.shutdownNow();
    log.info("Shutdown metric verification task with " + pending.size() + " tasks");

    interruptMe();
}

From source file:org.yccheok.jstock.engine.StockHistoryMonitor.java

public void clearStockCodes() {
    writerLock.lock();/*from   ww  w  . j av  a2 s .c  om*/

    try {
        final ThreadPoolExecutor threadPoolExecutor = ((ThreadPoolExecutor) pool);
        final int nThreads = threadPoolExecutor.getMaximumPoolSize();

        stockCodes.clear();

        histories.clear();

        threadPoolExecutor.shutdownNow();

        // pool is not valid any more. Discard it and re-create.
        pool = Executors.newFixedThreadPool(nThreads);
    } finally {
        writerLock.unlock();
    }
}

From source file:se.jiderhamn.classloader.leak.prevention.ClassLoaderLeakPreventor.java

/**
 * Partially inspired by org.apache.catalina.loader.WebappClassLoader.clearReferencesThreads()
 *//*from   w ww  .j a v a  2  s .  c  o  m*/
@SuppressWarnings("deprecation")
protected void stopThreads() {
    final Class<?> workerClass = findClass("java.util.concurrent.ThreadPoolExecutor$Worker");
    final Field oracleTarget = findField(Thread.class, "target"); // Sun/Oracle JRE
    final Field ibmRunnable = findField(Thread.class, "runnable"); // IBM JRE

    for (Thread thread : getAllThreads()) {
        final Runnable runnable = (oracleTarget != null) ? (Runnable) getFieldValue(oracleTarget, thread) : // Sun/Oracle JRE  
                (Runnable) getFieldValue(ibmRunnable, thread); // IBM JRE

        if (thread != Thread.currentThread() && // Ignore current thread
                (isThreadInWebApplication(thread) || isLoadedInWebApplication(runnable))) {

            if (thread.getClass().getName().startsWith(JURT_ASYNCHRONOUS_FINALIZER)) {
                // Note, the thread group of this thread may be "system" if it is triggered by the Garbage Collector
                // however if triggered by us in forceStartOpenOfficeJurtCleanup() it may depend on the application server
                if (stopThreads) {
                    info("Found JURT thread " + thread.getName() + "; starting "
                            + JURTKiller.class.getSimpleName());
                    new JURTKiller(thread).start();
                } else
                    warn("JURT thread " + thread.getName() + " is still running in web app");
            } else if (thread.getThreadGroup() != null && ("system".equals(thread.getThreadGroup().getName()) || // System thread
                    "RMI Runtime".equals(thread.getThreadGroup().getName()))) { // RMI thread (honestly, just copied from Tomcat)

                if ("Keep-Alive-Timer".equals(thread.getName())) {
                    thread.setContextClassLoader(getWebApplicationClassLoader().getParent());
                    debug("Changed contextClassLoader of HTTP keep alive thread");
                }
            } else if (thread.isAlive()) { // Non-system, running in web app

                if ("java.util.TimerThread".equals(thread.getClass().getName())) {
                    if (stopTimerThreads) {
                        warn("Stopping Timer thread running in classloader.");
                        stopTimerThread(thread);
                    } else {
                        info("Timer thread is running in classloader, but will not be stopped");
                    }
                } else {
                    // If threads is running an java.util.concurrent.ThreadPoolExecutor.Worker try shutting down the executor
                    if (workerClass != null && workerClass.isInstance(runnable)) {
                        if (stopThreads) {
                            warn("Shutting down " + ThreadPoolExecutor.class.getName()
                                    + " running within the classloader.");
                            try {
                                // java.util.concurrent.ThreadPoolExecutor, introduced in Java 1.5
                                final Field workerExecutor = findField(workerClass, "this$0");
                                final ThreadPoolExecutor executor = getFieldValue(workerExecutor, runnable);
                                executor.shutdownNow();
                            } catch (Exception ex) {
                                error(ex);
                            }
                        } else
                            info(ThreadPoolExecutor.class.getName()
                                    + " running within the classloader will not be shut down.");
                    }

                    final String displayString = "'" + thread + "' of type " + thread.getClass().getName();

                    if (stopThreads) {
                        final String waitString = (threadWaitMs > 0) ? "after " + threadWaitMs + " ms " : "";
                        warn("Stopping Thread " + displayString + " running in web app " + waitString);

                        if (threadWaitMs > 0) {
                            try {
                                thread.join(threadWaitMs); // Wait for thread to run
                            } catch (InterruptedException e) {
                                // Do nothing
                            }
                        }

                        // Normally threads should not be stopped (method is deprecated), since it may cause an inconsistent state.
                        // In this case however, the alternative is a classloader leak, which may or may not be considered worse.
                        if (thread.isAlive())
                            thread.stop();
                    } else {
                        warn("Thread " + displayString + " is still running in web app");
                    }

                }
            }
        }
    }
}