AsyncRunLevelContext.java

/*
 * Copyright (c) 2013, 2024 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

package org.glassfish.hk2.runlevel.internal;

import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Timer;
import java.util.concurrent.Executor;
import java.util.concurrent.SynchronousQueue;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.ReentrantLock;
import java.util.concurrent.locks.Condition;
import java.util.logging.Level;
import java.util.logging.Logger;

import jakarta.inject.Inject;

import org.glassfish.hk2.api.ActiveDescriptor;
import org.glassfish.hk2.api.Context;
import org.glassfish.hk2.api.DescriptorVisibility;
import org.glassfish.hk2.api.MultiException;
import org.glassfish.hk2.api.ServiceHandle;
import org.glassfish.hk2.api.ServiceLocator;
import org.glassfish.hk2.api.Visibility;
import org.glassfish.hk2.runlevel.CurrentlyRunningException;
import org.glassfish.hk2.runlevel.RunLevel;
import org.glassfish.hk2.runlevel.RunLevelController;
import org.glassfish.hk2.runlevel.RunLevelFuture;
import org.glassfish.hk2.runlevel.utilities.Utilities;
import org.jvnet.hk2.annotations.Service;

/**
 * @author jwells
 *
 */
@Service @Visibility(DescriptorVisibility.LOCAL)
public class AsyncRunLevelContext {
    private final static String DEBUG_CONTEXT_PROPERTY = "org.jvnet.hk2.properties.debug.runlevel.context";
    private final static boolean DEBUG_CONTEXT = AccessController.doPrivileged(new PrivilegedAction<Boolean>() {
        @Override
        public Boolean run() {
            return Boolean.parseBoolean(System.getProperty(DEBUG_CONTEXT_PROPERTY, "false"));
        }
            
    });
    
    private static final Logger logger = Logger.getLogger(AsyncRunLevelContext.class.getName());
    
    private static final Timer TIMER = new Timer("hk2-asyncrunlevelcontext", true);
    
    private static final ThreadFactory THREAD_FACTORY = new RunLevelThreadFactory();
    
    final ReentrantLock lock = new ReentrantLock();
    private final Condition notEmpty = lock.newCondition();
    private final org.glassfish.hk2.utilities.reflection.Logger hk2Logger = org.glassfish.hk2.utilities.reflection.Logger.getLogger();
    
    private int currentLevel = RunLevel.RUNLEVEL_VAL_INITIAL;
    private CurrentTaskFutureWrapper currentTask = null;
    
    private static final Executor DEFAULT_EXECUTOR = new ThreadPoolExecutor(0, Integer.MAX_VALUE,
            60L, TimeUnit.SECONDS,
            new SynchronousQueue<Runnable>(true),
            THREAD_FACTORY);
    
    /**
     * The backing maps for this context.
     */
    private final Map<ActiveDescriptor<?>, Object> backingMap =
            new HashMap<ActiveDescriptor<?>, Object>();
    
    /*
     * The within level errors thrown.  This prevents double
     * starting a service that failed within a level
     */
    private final Map<ActiveDescriptor<?>, Throwable> levelErrorMap =
            new HashMap<ActiveDescriptor<?>, Throwable>();
    
    private boolean wasCancelled = false;
    
    /**
     * The set of services currently being created
     */
    private final HashMap<ActiveDescriptor<?>, Long> creatingDescriptors = new HashMap<ActiveDescriptor<?>, Long>();
    
    /**
     * The set of descriptors that have been hard cancelled
     */
    private final HashSet<ActiveDescriptor<?>> hardCancelledDescriptors = new HashSet<ActiveDescriptor<?>>();
    
    private final LinkedList<ActiveDescriptor<?>> orderedCreationList = new LinkedList<ActiveDescriptor<?>>();
    
    private Executor executor = DEFAULT_EXECUTOR;
    private final ServiceLocator locator;
    private int maxThreads = Integer.MAX_VALUE;
    private RunLevelController.ThreadingPolicy policy = RunLevelController.ThreadingPolicy.FULLY_THREADED;
    private long cancelTimeout = 5 * 1000;
    private Integer modeOverride = null;
    
    /**
     * Constructor for the guy who does the work
     * 
     * @param locator The locator to use
     */
    @Inject
    private AsyncRunLevelContext(ServiceLocator locator) {
        this.locator = locator;
    }

    /**
     * This is from the {@link Context} API, called by the wrapper
     * 
     * @param activeDescriptor the descriptor to create
     * @param root The root descriptor
     * @return The object created
     */
    @SuppressWarnings("unchecked")
    public <U> U findOrCreate(ActiveDescriptor<U> activeDescriptor,
            ServiceHandle<?> root) {
        String oneLineDescriptor = null;
        if (DEBUG_CONTEXT) {
            oneLineDescriptor = oneLineDescriptor(activeDescriptor);
            hk2Logger.debug("AsyncRunLevelController findOrCreate for " + oneLineDescriptor + " and root " + oneLineRoot(root));
        }
        
        boolean throwWouldBlock;
        if (root == null) {
            throwWouldBlock = false;
        }
        else {
            Object rootBlockObject = root.getServiceData();
            if (rootBlockObject == null) {
                throwWouldBlock = false;
            }
            else {
                throwWouldBlock = ((Boolean) rootBlockObject).booleanValue();
            }
        }
        
        U retVal = null;
        
        int localCurrentLevel;
        Integer localModeOverride;
        long tid = -1L;
        
        lock.lock();
        try {
            localModeOverride = modeOverride;
            
            retVal = (U) backingMap.get(activeDescriptor);
            if (retVal != null) {
                if (DEBUG_CONTEXT) {
                    hk2Logger.debug("AsyncRunLevelController found " + oneLineDescriptor);
                }
                return retVal;
            }
            
            Throwable previousException = levelErrorMap.get(activeDescriptor);
            if (previousException != null) {
                if (DEBUG_CONTEXT) {
                    hk2Logger.debug("AsyncRunLevelController tried once, it failed, rethrowing " + oneLineDescriptor, previousException);
                }
                
                if (previousException instanceof RuntimeException) {
                    throw (RuntimeException) previousException;
                }
                
                throw new RuntimeException(previousException);
            }
            
            if (hardCancelledDescriptors.contains(activeDescriptor)) {
                if (DEBUG_CONTEXT) {
                    hk2Logger.debug("AsyncRunLevelController hard cancelled " + oneLineDescriptor);
                }
                throw new MultiException(new WasCancelledException(activeDescriptor), false);
            }
            
            while (creatingDescriptors.containsKey(activeDescriptor)) {
                if (DEBUG_CONTEXT) {
                    hk2Logger.debug("AsyncRunLevelController already being created " + oneLineDescriptor);
                }
                
                long holdingLock = creatingDescriptors.get(activeDescriptor);
                if (holdingLock == Thread.currentThread().getId()) {
                    if (DEBUG_CONTEXT) {
                        hk2Logger.debug("AsyncRunLevelController circular dependency " + oneLineDescriptor);
                    }
                    throw new MultiException(new IllegalStateException(
                            "Circular dependency involving " + activeDescriptor.getImplementation() +
                            " was found.  Full descriptor is " + activeDescriptor));
                }
                
                if (throwWouldBlock) {
                    if (DEBUG_CONTEXT) {
                        hk2Logger.debug("AsyncRunLevelController would block optimization " + oneLineDescriptor);
                    }
                    throw new MultiException(new WouldBlockException(activeDescriptor), false);
                }
                
                try {
                    notEmpty.await();
                }
                catch (InterruptedException ie) {
                    throw new MultiException(ie);
                }
            }
            if (DEBUG_CONTEXT) {
                hk2Logger.debug("AsyncRunLevelController finished creating wait for " + oneLineDescriptor);
            }
            
            retVal = (U) backingMap.get(activeDescriptor);
            if (retVal != null) {
                if (DEBUG_CONTEXT) {
                    hk2Logger.debug("AsyncRunLevelController second chance found " + oneLineDescriptor);
                }
                return retVal;
            }
            
            previousException = levelErrorMap.get(activeDescriptor);
            if (previousException != null) {
                if (DEBUG_CONTEXT) {
                    hk2Logger.debug("AsyncRunLevelController service already threw " + oneLineDescriptor);
                }
                
                if (previousException instanceof RuntimeException) {
                    throw (RuntimeException) previousException;
                }
                
                throw new RuntimeException(previousException);
            }
            
            if (hardCancelledDescriptors.contains(activeDescriptor)) {
                if (DEBUG_CONTEXT) {
                    hk2Logger.debug("AsyncRunLevelController second chance hard cancel " + oneLineDescriptor);
                }
                throw new MultiException(new WasCancelledException(activeDescriptor), false);
            }
            
            tid = Thread.currentThread().getId();
            if (DEBUG_CONTEXT) {
                hk2Logger.debug("AsyncRunLevelController am creating " + oneLineDescriptor + " in thread " + tid);
            }
            creatingDescriptors.put(activeDescriptor, tid);
            
            localCurrentLevel = currentLevel;
            if (currentTask != null && currentTask.isUp()) {
                localCurrentLevel++;
                
                if (localCurrentLevel > currentTask.getProposedLevel()) {
                    localCurrentLevel = currentTask.getProposedLevel();
                }
            }
        } finally {
            lock.unlock();
        }
        
        Throwable error = null;
        try {
            int mode = Utilities.getRunLevelMode(locator, activeDescriptor, localModeOverride);

            if (mode == RunLevel.RUNLEVEL_MODE_VALIDATING) {
                validate(activeDescriptor, localCurrentLevel);
            }

            if (DEBUG_CONTEXT) {
                hk2Logger.debug("AsyncRunLevelController prior to actual create " + oneLineDescriptor + " in thread " + tid);
            }
            retVal = activeDescriptor.create(root);
            if (DEBUG_CONTEXT) {
                hk2Logger.debug("AsyncRunLevelController after actual create " + oneLineDescriptor + " in thread " + tid);
            }
            
            return retVal;
        }
        catch (Throwable th) {
            if (DEBUG_CONTEXT) {
                hk2Logger.debug("AsyncRunLevelController got exception for " + oneLineDescriptor + " in thread " + tid, th);
            }
            
            if (th instanceof MultiException) {
                if (!CurrentTaskFuture.isWouldBlock((MultiException) th)) {
                    error = th;
                }
                
                // We want WouldBlock rethrown
            }
            else {
                error = th;
            }
            
            if (th instanceof RuntimeException) {
                throw (RuntimeException) th;
            }
            
            throw new RuntimeException(th);
        }
        finally {
            lock.lock();
            try {
                boolean hardCancelled = hardCancelledDescriptors.remove(activeDescriptor);
                
                if (retVal != null) {
                    if (!hardCancelled) {
                        backingMap.put(activeDescriptor, retVal);
                        orderedCreationList.addFirst(activeDescriptor);
                    }
                    
                    if (wasCancelled || hardCancelled) {
                        if (DEBUG_CONTEXT) {
                            hk2Logger.debug("AsyncRunLevelController cancellation race failed " + oneLineDescriptor + " in thread " + tid);
                        }
                        // Even though this service actually ran to completion, we
                        // are going to pretend it failed.  Putting it in the lists
                        // above will ensure it gets properly shutdown
                        
                        MultiException cancelledException = new MultiException(new WasCancelledException(activeDescriptor), false);
                        
                        if (!hardCancelled) {
                            levelErrorMap.put(activeDescriptor, cancelledException);
                        }
                        
                        creatingDescriptors.remove(activeDescriptor);
                        notEmpty.signalAll();
                        if (DEBUG_CONTEXT) {
                            hk2Logger.debug("AsyncRunLevelController other threads notified cancellation path for " +
                                oneLineDescriptor + " in thread " + tid);
                        }
                        
                        throw cancelledException;
                    }
                }
                else if (error != null) {
                    if (!hardCancelled) {
                        levelErrorMap.put(activeDescriptor, error);
                    }
                }
                
                creatingDescriptors.remove(activeDescriptor);
                notEmpty.signalAll();
                if (DEBUG_CONTEXT) {
                    hk2Logger.debug("AsyncRunLevelController other threads notified for " +
                        oneLineDescriptor + " in thread " + tid);
                }
            } finally {
                lock.unlock();
            }
        }
    }

    /**
     * The {@link Context} API for discovering if a descriptor has been created
     * 
     * @param descriptor The descriptor to find
     * @return true if already created, false otherwise
     */
    public boolean containsKey(ActiveDescriptor<?> descriptor) {
        lock.lock();
        try {
            return backingMap.containsKey(descriptor);
        } finally {
            lock.unlock();
        }
    }
    
    /* package */ boolean wouldBlockRightNow(ActiveDescriptor<?> desc) {
        lock.lock();
        try {
            return creatingDescriptors.containsKey(desc);
        } finally {
            lock.unlock();
        }
    }
    
    /**
     * No need to lock this, it is called with the lock already held
     * 
     * @param descriptor the non-null descriptor to hard cancel
     */
    /* package */ void hardCancelOne(ActiveDescriptor<?> descriptor) {
        if (creatingDescriptors.containsKey(descriptor)) {
            // This guy has been hard-cancelled, mark it down
            hardCancelledDescriptors.add(descriptor);
        }
    }
    
    /**
     * The {@link Context} API.  Removes a descriptor from the set
     * 
     * @param descriptor The descriptor to destroy
     */
    @SuppressWarnings("unchecked")
    public void destroyOne(ActiveDescriptor<?> descriptor) {
        Object retVal = null;
        lock.lock();
        try {
            retVal = backingMap.remove(descriptor);
            if (retVal == null) return;
        } finally {
            lock.unlock();
        }
            
        ((ActiveDescriptor<Object>) descriptor).dispose(retVal);
    }
    
    /**
     * Verifies that the run level value of the {@link RunLevel} annotated
     * service described by the given descriptor is valid for activation.
     * Valid means that the run level value is less than or equal to the
     * current or planned run level of the given {@link org.glassfish.hk2.runlevel.RunLevelController}.
     *
     * @param descriptor  the descriptor of the service being activated
     * @param service     the run level service
     *
     * @throws RunLevelException if the validation fails
     */
    private void validate(ActiveDescriptor<?> descriptor, int currentLevel) throws IllegalStateException {

        Integer runLevel = Utilities.getRunLevelValue(locator, descriptor);

        if (runLevel > currentLevel) {
            throw new IllegalStateException("Service " + descriptor.getImplementation() +
                    " was started at level " + currentLevel + " but it has a run level of " +
                    runLevel + ".  The full descriptor is " + descriptor);
        }
    }

    
    /* package */ int getCurrentLevel() {
        lock.lock();
        try {
            return currentLevel;
        } finally {
            lock.unlock();
        }
    }
    
    /* package */ void levelCancelled() {
        lock.lock();
        try {
            wasCancelled = true;
        } finally {
            lock.unlock();
        }
    }

    /* package */ void setCurrentLevel(int currentLevel) {
        lock.lock();
        try {
            this.currentLevel = currentLevel;
        } finally {
            lock.unlock();
        }
    }
    
    /* package */ void setPolicy(RunLevelController.ThreadingPolicy policy) {
        lock.lock();
        try {
            this.policy = policy;
        } finally {
            lock.unlock();
        }
    }
    
    /* package */ void setExecutor(Executor executor) {
        lock.lock();
        try {
            if (executor == null) {
                this.executor = DEFAULT_EXECUTOR;
            }
            else {
                this.executor = executor;
            }
        } finally {
            lock.unlock();
        }
    }
    
    /* package */ Executor getExecutor() {
        lock.lock();
        try {
            return executor;
        } finally {
            lock.unlock();
        }
    }
    
    /* package */ RunLevelController.ThreadingPolicy getPolicy() {
        lock.lock();
        try {
            return policy;
        } finally {
            lock.unlock();
        }
    }
    
    /* package */ List<ActiveDescriptor<?>> getOrderedListOfServicesAtLevel(int level) {
        lock.lock();
        try {
            LinkedList<ActiveDescriptor<?>> retVal = new LinkedList<ActiveDescriptor<?>>();
            
            while (!orderedCreationList.isEmpty()) {
                ActiveDescriptor<?> zero = orderedCreationList.get(0);
                
                int zeroLevel = Utilities.getRunLevelValue(locator, zero);
                
                if (zeroLevel < level) return retVal;
                
                retVal.add(orderedCreationList.remove(0));
            }
            
            return retVal;
        } finally {
            lock.unlock();
        }
        
    }
    
    /**
     * This method is called to change the proceedTo level of the system
     * @param level The level to change to
     * @return A non-null RunLevelFuture that is the handle to give the
     * caller
     * @throws CurrentlyRunningException If there is already a running job
     */
    public RunLevelFuture proceedTo(int level) throws CurrentlyRunningException {
        CurrentTaskFutureWrapper localTask;
        lock.lock();
        try {
            boolean fullyThreaded = policy.equals(RunLevelController.ThreadingPolicy.FULLY_THREADED);
            
            if (currentTask != null) {
                throw new CurrentlyRunningException(currentTask);
            }
            
            currentTask = new CurrentTaskFutureWrapper(new CurrentTaskFuture(this,
                    executor,
                    locator,
                    level,
                    maxThreads,
                    fullyThreaded,
                    cancelTimeout,
                    TIMER));
            
            localTask = currentTask;
        } finally {
            lock.unlock();
        }
        
        // Do outside the lock so that when not fully threaded we do not hold the
        // AsyncRunLevelContext lock.  Otherwise this can lead to deadlock
        localTask.getDelegate().go();
            
        return localTask;
    }
    
    /* package */ void jobDone() {
        lock.lock();
        try {
            currentTask = null;
        } finally {
            lock.unlock();
        }
    }
    
    /**
     * Gets the current task
     * 
     * @return The current task, may be null if there is no current task
     */
    public RunLevelFuture getCurrentFuture() {
        lock.lock();
        try {
            return currentTask;
        } finally {
            lock.unlock();
        }
    }
    
    /* package */ void setMaximumThreads(int maximum) {
        lock.lock();
        try {
            if (maximum < 1) {
                maxThreads = 1;
            }
            else {
                maxThreads = maximum;
            }
        } finally {
            lock.unlock();
        }
    }
    
    /* package */ int getMaximumThreads() {
        lock.lock();
        try {
            return maxThreads;
        } finally {
            lock.unlock();
        }
    }
    
    /* package */ void clearErrors() {
        lock.lock();
        try {
            levelErrorMap.clear();
            wasCancelled = false;
        } finally {
            lock.unlock();
        }
    }
    
    /* package */ void setCancelTimeout(long cancelTimeout) {
        lock.lock();
        try {
            this.cancelTimeout = cancelTimeout;
        } finally {
            lock.unlock();
        }
    }
    
    /* package */ long getCancelTimeout() {
        lock.lock();
        try {
            return cancelTimeout;
        } finally {
            lock.unlock();
        }
    }
    
    /* package */ Integer getModeOverride() {
        lock.lock();
        try {
            return modeOverride;
        } finally {
            lock.unlock();
        }
    }
    
    /* package */ void setModeOverride(Integer modeOverride) {
        lock.lock();
        try {
            this.modeOverride = modeOverride;
        } finally {
            lock.unlock();
        }
    }
    
    private static class RunLevelControllerThread extends Thread {
        private RunLevelControllerThread(Runnable r) {
            super(r);
            setDaemon(true);
            setName(getClass().getSimpleName() + "-"
                    + System.currentTimeMillis());
        }
    }
    
    private static class RunLevelThreadFactory implements ThreadFactory {
        @Override
        public Thread newThread(Runnable runnable) {
            Thread activeThread = new RunLevelControllerThread(runnable);
                
            logger.log(Level.FINE, "new thread: {0}", activeThread);
                
            return activeThread;
        }
    }
    
    private static String oneLineDescriptor(ActiveDescriptor<?> descriptor) {
        if (descriptor == null) return "null-descriptor";
        
        return descriptor.getImplementation() +
                ((descriptor.getName() != null) ? "/" + descriptor.getName() : "") +
                "(" + descriptor.getServiceId() + "," + descriptor.getLocatorId() + "," + System.identityHashCode(descriptor) + ")";
    }
    
    private static String oneLineRoot(ServiceHandle<?> root) {
        if (root == null) return "null-root";
        
        root.getActiveDescriptor();
        
        return "root(" + oneLineDescriptor(root.getActiveDescriptor()) + "," + System.identityHashCode(root) + ")";
    }
}