/*
 * Copyright 2003-2006 Sun Microsystems, Inc.  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.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */

package sun.management;

import java.lang.management.*;
import java.util.logging.LogManager;

import javax.management.DynamicMBean;
import javax.management.MBeanServer;
import javax.management.MBeanServerFactory;
import javax.management.MBeanInfo;
import javax.management.NotificationEmitter;
import javax.management.ObjectName;
import javax.management.ObjectInstance;
import javax.management.InstanceAlreadyExistsException;
import javax.management.InstanceNotFoundException;
import javax.management.MBeanRegistrationException;
import javax.management.NotCompliantMBeanException;
import javax.management.MalformedObjectNameException;
import javax.management.RuntimeOperationsException;
import javax.management.StandardEmitterMBean;
import javax.management.StandardMBean;
import java.security.AccessController;
import java.security.Permission;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import sun.security.action.LoadLibraryAction;

import java.util.ArrayList;
import java.util.List;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.Iterator;
import java.util.ListIterator;
import com.sun.management.OSMBeanFactory;
import com.sun.management.HotSpotDiagnosticMXBean;

import static java.lang.management.ManagementFactory.*;

/**
 * ManagementFactory provides static factory methods to create
 * instances of the management interface.
 */
public class ManagementFactory {
    private ManagementFactory() {};

    private static VMManagement jvm;

    private static boolean mbeansCreated = false;
    private static ClassLoadingImpl    classMBean = null;
    private static MemoryImpl          memoryMBean = null;
    private static ThreadImpl          threadMBean = null;
    private static RuntimeImpl         runtimeMBean = null;
    private static CompilationImpl     compileMBean = null;
    private static OperatingSystemImpl osMBean = null;

    public static synchronized ClassLoadingMXBean getClassLoadingMXBean() {
        if (classMBean == null) {
            classMBean = new ClassLoadingImpl(jvm);
        }
        return classMBean;
    }

    public static synchronized MemoryMXBean getMemoryMXBean() {
        if (memoryMBean == null) {
            memoryMBean = new MemoryImpl(jvm);
        }
        return memoryMBean;
    }

    public static synchronized ThreadMXBean getThreadMXBean() {
        if (threadMBean == null) {
            threadMBean = new ThreadImpl(jvm);
        }
        return threadMBean;
    }

    public static synchronized RuntimeMXBean getRuntimeMXBean() {
        if (runtimeMBean == null) {
            runtimeMBean = new RuntimeImpl(jvm);
        }
        return runtimeMBean;
    }

    public static synchronized CompilationMXBean getCompilationMXBean() {
        if (compileMBean == null && jvm.getCompilerName() != null) {
            compileMBean = new CompilationImpl(jvm);
        }
        return compileMBean;
    }

    public static synchronized OperatingSystemMXBean getOperatingSystemMXBean() {
        if (osMBean == null) {
            osMBean = (OperatingSystemImpl)
                          OSMBeanFactory.getOperatingSystemMXBean(jvm);
        }
        return osMBean;
    }

    public static List<MemoryPoolMXBean> getMemoryPoolMXBeans() {
        MemoryPoolMXBean[] pools = MemoryImpl.getMemoryPools();
        List<MemoryPoolMXBean> list = new ArrayList<MemoryPoolMXBean>(pools.length);
        for (int i = 0; i < pools.length; i++) {
            MemoryPoolMXBean p = pools[i];
            list.add(p);
        }
        return list;
    }

    public static List<MemoryManagerMXBean> getMemoryManagerMXBeans() {
        MemoryManagerMXBean[]  mgrs = MemoryImpl.getMemoryManagers();
        List<MemoryManagerMXBean> result = new ArrayList<MemoryManagerMXBean>(mgrs.length);
        for (int i = 0; i < mgrs.length; i++) {
            MemoryManagerMXBean m = mgrs[i];
            result.add(m);
        }
        return result;
    }

    public static List<GarbageCollectorMXBean> getGarbageCollectorMXBeans() {
        MemoryManagerMXBean[]  mgrs = MemoryImpl.getMemoryManagers();
        List<GarbageCollectorMXBean> result = new ArrayList<GarbageCollectorMXBean>(mgrs.length);
        for (int i = 0; i < mgrs.length; i++) {
            if (mgrs[i] instanceof GarbageCollectorMXBean) {
                GarbageCollectorMXBean gc = (GarbageCollectorMXBean) mgrs[i];
                result.add(gc);
            }
        }
        return result;
    }

    private static HotSpotDiagnostic hsDiagMBean = null;
    private static HotspotRuntime hsRuntimeMBean = null;
    private static HotspotClassLoading hsClassMBean = null;
    private static HotspotThread hsThreadMBean = null;
    private static HotspotCompilation hsCompileMBean = null;
    private static HotspotMemory hsMemoryMBean = null;

    public static synchronized HotSpotDiagnosticMXBean getDiagnosticMXBean() {
        if (hsDiagMBean == null) {
            hsDiagMBean = new HotSpotDiagnostic();
        }
        return hsDiagMBean;
    }

    /**

    /**
     * This method is for testing only.
     */
    public static synchronized HotspotRuntimeMBean getHotspotRuntimeMBean() {
        if (hsRuntimeMBean == null) {
            hsRuntimeMBean = new HotspotRuntime(jvm);
        }
        return hsRuntimeMBean;
    }

    /**
     * This method is for testing only.
     */
    public static synchronized HotspotClassLoadingMBean getHotspotClassLoadingMBean() {
        if (hsClassMBean == null) {
            hsClassMBean = new HotspotClassLoading(jvm);
        }
        return hsClassMBean;
    }

    /**
     * This method is for testing only.
     */
    public static synchronized HotspotThreadMBean getHotspotThreadMBean() {
        if (hsThreadMBean == null) {
            hsThreadMBean = new HotspotThread(jvm);
        }
        return hsThreadMBean;
    }

    /**
     * This method is for testing only.
     */
    public static synchronized HotspotMemoryMBean getHotspotMemoryMBean() {
        if (hsMemoryMBean == null) {
            hsMemoryMBean = new HotspotMemory(jvm);
        }
        return hsMemoryMBean;
    }

    /**
     * This method is for testing only.
     */
    public static synchronized HotspotCompilationMBean getHotspotCompilationMBean() {
        if (hsCompileMBean == null) {
            hsCompileMBean = new HotspotCompilation(jvm);
        }
        return hsCompileMBean;
    }

    private static Permission monitorPermission =
        new ManagementPermission("monitor");
    private static Permission controlPermission =
        new ManagementPermission("control");

    /**
     * Check that the current context is trusted to perform monitoring
     * or management.
     * <p>
     * If the check fails we throw a SecurityException, otherwise
     * we return normally.
     *
     * @exception  SecurityException  if a security manager exists and if
     *             the caller does not have ManagementPermission("control").
     */
    static void checkAccess(Permission p)
         throws SecurityException {
        SecurityManager sm = System.getSecurityManager();
        if (sm != null) {
            sm.checkPermission(p);
        }
    }

    static void checkMonitorAccess() throws SecurityException {
        checkAccess(monitorPermission);
    }
    static void checkControlAccess() throws SecurityException {
        checkAccess(controlPermission);
    }

    /**
     * Registers an MXBean and throws exception if an instance with the same
     * name exists.
     *
     * This method makes a DynamicMBean out of an MXBean by wrapping it with a
     * StandardMBean (StandardEmitterMBean if the supplied emitter is not null),
     * so it can be registered in an MBeanServer which does not have support for
     * MXBeans.
     */
    private static void addMXBean(MBeanServer mbs, Object mbean,
                                  String mbeanName, NotificationEmitter emitter) {
        // Make DynamicMBean out of MXBean by wrapping it with a StandardMBean
        //
        final DynamicMBean dmbean;
        if (emitter == null) {
            dmbean = new StandardMBean(mbean, null, true);
        } else {
            dmbean = new StandardEmitterMBean(mbean, null, true, emitter);
        }
        addMBean(mbs, dmbean, mbeanName, false);
    }

    /**
     * Registers a Standard MBean or a Dynamic MBean and throws
     * exception if an instance with the same name exists.
     */
    private static void addMBean(MBeanServer mbs, Object mbean, String mbeanName) {
        addMBean(mbs, mbean, mbeanName, false);
    }

    private static void addMBean(MBeanServer mbs, Object mbean,
                                 String mbeanName, boolean ignoreConflicts) {
        try {
            final ObjectName objName = new ObjectName(mbeanName);

            // inner class requires these fields to be final
            final MBeanServer mbs0 = mbs;
            final Object mbean0 = mbean;
            final boolean ignore = ignoreConflicts;
            AccessController.doPrivileged(new PrivilegedExceptionAction<Object>() {
                public Object run() throws InstanceAlreadyExistsException,
                                           MBeanRegistrationException,
                                           NotCompliantMBeanException {
                    try {
                        ObjectInstance o = mbs0.registerMBean(mbean0,
                                                              objName);
                        return null;
                    } catch (InstanceAlreadyExistsException e) {
                        // if an instance with the object name exists in
                        // the MBeanServer ignore the exception
                        // if ignoreConflicts is true;
                        // otherwise, throws exception.
                        if (!ignore) {
                             throw e;
                        }
                    }
                    return null;
                }
            });
        } catch (PrivilegedActionException e) {
            throw Util.newException(e.getException());
        } catch (MalformedObjectNameException e) {
            // should not reach here
            throw Util.newException(e);
        }
    }

    public static MBeanServer createPlatformMBeanServer() {
        MBeanServer mbs = MBeanServerFactory.createMBeanServer();
        // Register all the platform MBeans to this MBeanServer
        addMXBean(mbs, getClassLoadingMXBean(),
                  CLASS_LOADING_MXBEAN_NAME, null);
        addMXBean(mbs, getMemoryMXBean(),
                  MEMORY_MXBEAN_NAME, (NotificationEmitter) getMemoryMXBean());
        addMXBean(mbs, getOperatingSystemMXBean(),
                  OPERATING_SYSTEM_MXBEAN_NAME, null);
        addMXBean(mbs, getRuntimeMXBean(),
                  RUNTIME_MXBEAN_NAME, null);
        addMXBean(mbs, getThreadMXBean(),
                  THREAD_MXBEAN_NAME, null);
        addMXBean(mbs, getDiagnosticMXBean(),
                  HOTSPOT_DIAGNOSTIC_MXBEAN_NAME, null);

        // CompilationMBean may not exist
        if (getCompilationMXBean() != null) {
            addMXBean(mbs, getCompilationMXBean(),
                      COMPILATION_MXBEAN_NAME, null);
        }

        // Register MBeans for memory pools and memory managers
        addMemoryManagers(mbs);
        addMemoryPools(mbs);

        // Register platform extension
        addMXBean(mbs, LogManager.getLoggingMXBean(),
                  LogManager.LOGGING_MXBEAN_NAME, null);

        return mbs;
    }

    private final static String HOTSPOT_DIAGNOSTIC_MXBEAN_NAME =
        "com.sun.management:type=HotSpotDiagnostic";

    private final static String HOTSPOT_CLASS_LOADING_MBEAN_NAME =
        "sun.management:type=HotspotClassLoading";

    private final static String HOTSPOT_COMPILATION_MBEAN_NAME =
        "sun.management:type=HotspotCompilation";

    private final static String HOTSPOT_MEMORY_MBEAN_NAME =
        "sun.management:type=HotspotMemory";

    private static final String HOTSPOT_RUNTIME_MBEAN_NAME =
        "sun.management:type=HotspotRuntime";

    private final static String HOTSPOT_THREAD_MBEAN_NAME =
        "sun.management:type=HotspotThreading";

    private final static String HOTSPOT_INTERNAL_MBEAN_NAME =
        "sun.management:type=HotspotInternal";

    private static ObjectName hsInternalObjName = null;
    static synchronized ObjectName getHotspotInternalObjectName() {
        if (hsInternalObjName == null) {
            try {
                hsInternalObjName = new ObjectName(HOTSPOT_INTERNAL_MBEAN_NAME);
            } catch (MalformedObjectNameException e) {
                // should not reach here
                throw Util.newException(e);
            }
        }
        return hsInternalObjName;
    }

    static void registerInternalMBeans(MBeanServer mbs) {
        // register all internal MBeans if not registered
        // No exception is thrown if a MBean with that object name
        // already registered (i.e. ignore if name conflicts).
        addMBean(mbs, getHotspotClassLoadingMBean(),
            HOTSPOT_CLASS_LOADING_MBEAN_NAME, true);
        addMBean(mbs, getHotspotMemoryMBean(),
            HOTSPOT_MEMORY_MBEAN_NAME, true);
        addMBean(mbs, getHotspotRuntimeMBean(),
            HOTSPOT_RUNTIME_MBEAN_NAME, true);
        addMBean(mbs, getHotspotThreadMBean(),
            HOTSPOT_THREAD_MBEAN_NAME, true);

        // CompilationMBean may not exist
        if (getCompilationMXBean() != null) {
            addMBean(mbs, getHotspotCompilationMBean(),
                HOTSPOT_COMPILATION_MBEAN_NAME, true);
        }
    }

    private static void unregisterMBean(MBeanServer mbs, String mbeanName) {
        try {
            final ObjectName objName = new ObjectName(mbeanName);

            // inner class requires these fields to be final
            final MBeanServer mbs0 = mbs;
            AccessController.doPrivileged(new PrivilegedExceptionAction<Object>() {
                public Object run() throws MBeanRegistrationException,
                                           RuntimeOperationsException  {
                    try {
                        mbs0.unregisterMBean(objName);
                    } catch (InstanceNotFoundException e) {
                        // ignore exception if not found
                    }
                    return null;
                }
            });
        } catch (PrivilegedActionException e) {
            throw Util.newException(e.getException());
        } catch (MalformedObjectNameException e) {
            // should not reach here
            throw Util.newException(e);
        }
    }

    static void unregisterInternalMBeans(MBeanServer mbs) {
        // unregister all internal MBeans
        unregisterMBean(mbs, HOTSPOT_CLASS_LOADING_MBEAN_NAME);
        unregisterMBean(mbs, HOTSPOT_MEMORY_MBEAN_NAME);
        unregisterMBean(mbs, HOTSPOT_RUNTIME_MBEAN_NAME);
        unregisterMBean(mbs, HOTSPOT_THREAD_MBEAN_NAME);

        // CompilationMBean may not exist
        if (getCompilationMXBean() != null) {
            unregisterMBean(mbs, HOTSPOT_COMPILATION_MBEAN_NAME);
        }
    }

    private static synchronized void addMemoryPools(MBeanServer mbs) {

        // Get a list of memory pools
        MemoryPoolMXBean[] newPools = MemoryImpl.getMemoryPools();

        for (int i = 0; i < newPools.length; i++) {
            String poolObjNameString = Util.getMBeanObjectName(newPools[i]);
            addMXBean(mbs, newPools[i], poolObjNameString, null);
        }
    }

    // Register all memory managers with the MBeanServer;
    private static synchronized void addMemoryManagers(MBeanServer mbs) {

        // Get a list of memory managers
        MemoryManagerMXBean[] newMgrs = MemoryImpl.getMemoryManagers();

        for (int i = 0; i < newMgrs.length; i++) {
            String mgrObjNameString = Util.getMBeanObjectName(newMgrs[i]);
            addMXBean(mbs, newMgrs[i], mgrObjNameString, null);
        }
    }

    // Invoked by the VM
    private static MemoryPoolMXBean createMemoryPool
        (String name, boolean isHeap, long uThreshold, long gcThreshold) {
        return new MemoryPoolImpl(name, isHeap, uThreshold, gcThreshold);
    }

    private static MemoryManagerMXBean createMemoryManager(String name) {
        return new MemoryManagerImpl(name);
    }

    private static GarbageCollectorMXBean
        createGarbageCollector(String name, String type) {

        // ignore type parameter which is for future extension
        return new GarbageCollectorImpl(name);
    }

    static {
        AccessController.doPrivileged(new LoadLibraryAction("management"));
        jvm = new VMManagementImpl();
    }

    public static boolean isThreadSuspended(int state) {
        return ((state & JMM_THREAD_STATE_FLAG_SUSPENDED) != 0);
    }

    public static boolean isThreadRunningNative(int state) {
        return ((state & JMM_THREAD_STATE_FLAG_NATIVE) != 0);
    }

    public static Thread.State toThreadState(int state) {
        // suspended and native bits may be set in state
        int threadStatus = state & ~JMM_THREAD_STATE_FLAG_MASK;
        return sun.misc.VM.toThreadState(threadStatus);
    }

    // These values are defined in jmm.h
    private static final int JMM_THREAD_STATE_FLAG_MASK = 0xFFF00000;
    private static final int JMM_THREAD_STATE_FLAG_SUSPENDED = 0x00100000;
    private static final int JMM_THREAD_STATE_FLAG_NATIVE = 0x00400000;

}