/*

 * Copyright 2003-2005 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.ThreadMXBean;

import java.lang.management.ThreadInfo;

import java.lang.management.LockInfo;

import java.lang.management.MonitorInfo;

import java.util.Map;

import java.util.HashMap;

/**

 * Implementation class for the thread subsystem.

 * Standard and committed hotspot-specific metrics if any.

 *

 * ManagementFactory.getThreadMXBean() returns an instance

 * of this class.

 */

class ThreadImpl implements ThreadMXBean {

    private final VMManagement jvm;

    // default for thread contention monitoring is disabled.

    private boolean contentionMonitoringEnabled = false;

    private boolean cpuTimeEnabled;

    /**

     * Constructor of ThreadImpl class.

     */

    ThreadImpl(VMManagement vm) {

        this.jvm = vm;

        this.cpuTimeEnabled = jvm.isThreadCpuTimeEnabled();

    }

    public int getThreadCount() {

        return jvm.getLiveThreadCount();

    }

    public int getPeakThreadCount() {

        return jvm.getPeakThreadCount();

    }

    public long getTotalStartedThreadCount() {

        return jvm.getTotalThreadCount();

    }

    public int getDaemonThreadCount() {

        return jvm.getDaemonThreadCount();

    }

    public boolean isThreadContentionMonitoringSupported() {

        return jvm.isThreadContentionMonitoringSupported();

    }

    public synchronized boolean isThreadContentionMonitoringEnabled() {

       if (!isThreadContentionMonitoringSupported()) {

            throw new UnsupportedOperationException(

                "Thread contention monitoring is not supported.");

        }

        return contentionMonitoringEnabled;

    }

    public boolean isThreadCpuTimeSupported() {

        return jvm.isOtherThreadCpuTimeSupported();

    }

    public boolean isCurrentThreadCpuTimeSupported() {

        return jvm.isCurrentThreadCpuTimeSupported();

    }

    public boolean isThreadCpuTimeEnabled() {

        if (!isThreadCpuTimeSupported() &&

            !isCurrentThreadCpuTimeSupported()) {

            throw new UnsupportedOperationException(

                "Thread CPU time measurement is not supported");

        }

        return cpuTimeEnabled;

    }

    public long[] getAllThreadIds() {

        Thread[] threads = getThreads();

        int length = threads.length;

        long[] ids = new long[length];

        for (int i = 0; i < length; i++) {

            Thread t = threads[i];

            ids[i] = t.getId();

        }

        return ids;

    }

    public ThreadInfo getThreadInfo(long id) {

        if (id <= 0) {

            throw new IllegalArgumentException(

                "Invalid thread ID parameter: " + id);

        }

        long[] ids = new long[1];

        ids[0] = id;

        final ThreadInfo[] infos = getThreadInfo(ids, 0);

        return infos[0];

    }

    public ThreadInfo getThreadInfo(long id, int maxDepth) {

        if (id <= 0) {

            throw new IllegalArgumentException(

                "Invalid thread ID parameter: " + id);

        }

        if (maxDepth < 0) {

            throw new IllegalArgumentException(

                "Invalid maxDepth parameter: " + maxDepth);

        }

        long[] ids = new long[1];

        ids[0] = id;

        final ThreadInfo[] infos = getThreadInfo(ids, maxDepth);

        return infos[0];

    }

    public ThreadInfo[] getThreadInfo(long[] ids) {

        return getThreadInfo(ids, 0);

    }

    public ThreadInfo[] getThreadInfo(long[] ids, int maxDepth) {

        if (ids == null) {

            throw new NullPointerException("Null ids parameter.");

        }

        if (maxDepth < 0) {

            throw new IllegalArgumentException(

                "Invalid maxDepth parameter: " + maxDepth);

        }

        ThreadInfo[] infos = new ThreadInfo[ids.length];

        if (maxDepth == Integer.MAX_VALUE) {

            getThreadInfo0(ids, -1, infos);

        } else {

            getThreadInfo0(ids, maxDepth, infos);

        }

        return infos;

    }

    public void setThreadContentionMonitoringEnabled(boolean enable) {

        if (!isThreadContentionMonitoringSupported()) {

            throw new UnsupportedOperationException(

                "Thread contention monitoring is not supported");

        }

        synchronized (this) {

            if (contentionMonitoringEnabled != enable) {

                if (enable) {

                    // if reeabled, reset contention time statistics

                    // for all threads

                    resetContentionTimes0(0);

                }

                // update the VM of the state change

                setThreadContentionMonitoringEnabled0(enable);

                contentionMonitoringEnabled = enable;

            }

        }

    }

    public long getCurrentThreadCpuTime() {

        // check if Thread CPU time measurement is supported.

        if (!isCurrentThreadCpuTimeSupported()) {

            throw new UnsupportedOperationException(

                "Current thread CPU time measurement is not supported.");

        }

        if (!isThreadCpuTimeEnabled()) {

            return -1;

        }

        return getThreadTotalCpuTime0(0);

    }

    public long getThreadCpuTime(long id) {

        // check if Thread CPU time measurement is supported.

        if (!isThreadCpuTimeSupported() &&

            !isCurrentThreadCpuTimeSupported()) {

            throw new UnsupportedOperationException(

                "Thread CPU Time Measurement is not supported.");

        }

        if (!isThreadCpuTimeSupported()) {

            // support current thread only

            if (id != Thread.currentThread().getId()) {

                throw new UnsupportedOperationException(

                    "Thread CPU Time Measurement is only supported" +

                    " for the current thread.");

            }

        }

        if (id <= 0) {

            throw new IllegalArgumentException(

                "Invalid thread ID parameter: " + id);

        }

        if (!isThreadCpuTimeEnabled()) {

            return -1;

        }

        if (id == Thread.currentThread().getId()) {

            // current thread

            return getThreadTotalCpuTime0(0);

        } else {

            return getThreadTotalCpuTime0(id);

        }

    }

    public long getCurrentThreadUserTime() {

        // check if Thread CPU time measurement is supported.

        if (!isCurrentThreadCpuTimeSupported()) {

            throw new UnsupportedOperationException(

                "Current thread CPU time measurement is not supported.");

        }

        if (!isThreadCpuTimeEnabled()) {

            return -1;

        }

        return getThreadUserCpuTime0(0);

    }

    public long getThreadUserTime(long id) {

        // check if Thread CPU time measurement is supported.

        if (!isThreadCpuTimeSupported() &&

            !isCurrentThreadCpuTimeSupported()) {

            throw new UnsupportedOperationException(

                "Thread CPU time measurement is not supported.");

        }

        if (!isThreadCpuTimeSupported()) {

            // support current thread only

            if (id != Thread.currentThread().getId()) {

                throw new UnsupportedOperationException(

                    "Thread CPU time measurement is only supported" +

                    " for the current thread.");

            }

        }

        if (id <= 0) {

            throw new IllegalArgumentException(

                "Invalid thread ID parameter: " + id);

        }

        if (!isThreadCpuTimeEnabled()) {

            return -1;

        }

        if (id == Thread.currentThread().getId()) {

            // current thread

           return getThreadUserCpuTime0(0);

        } else {

           return getThreadUserCpuTime0(id);

        }

    }

    public void setThreadCpuTimeEnabled(boolean enable) {

        if (!isThreadCpuTimeSupported() &&

            !isCurrentThreadCpuTimeSupported()) {

            throw new UnsupportedOperationException(

                "Thread CPU time measurement is not supported");

        }

        synchronized (this) {

            if (cpuTimeEnabled != enable) {

                // update VM of the state change

                setThreadCpuTimeEnabled0(enable);

                cpuTimeEnabled = enable;

            }

        }

    }

    public long[] findMonitorDeadlockedThreads() {

        Thread[] threads = findMonitorDeadlockedThreads0();

        if (threads == null) {

            return null;

        }

        long[] ids = new long[threads.length];

        for (int i = 0; i < threads.length; i++) {

            Thread t = threads[i];

            ids[i] = t.getId();

        }

        return ids;

    }

    public long[] findDeadlockedThreads() {

        if (!isSynchronizerUsageSupported()) {

            throw new UnsupportedOperationException(

                "Monitoring of Synchronizer Usage is not supported.");

        }

        Thread[] threads = findDeadlockedThreads0();

        if (threads == null) {

            return null;

        }

        long[] ids = new long[threads.length];

        for (int i = 0; i < threads.length; i++) {

            Thread t = threads[i];

            ids[i] = t.getId();

        }

        return ids;

    }

    public void resetPeakThreadCount() {

        resetPeakThreadCount0();

    }

    public boolean isObjectMonitorUsageSupported() {

        return jvm.isObjectMonitorUsageSupported();

    }

    public boolean isSynchronizerUsageSupported() {

        return jvm.isSynchronizerUsageSupported();

    }

    public ThreadInfo[] getThreadInfo(long[] ids,

                                      boolean lockedMonitors,

                                      boolean lockedSynchronizers) {

        if (ids == null) {

            throw new NullPointerException("Null ids parameter.");

        }

        if (lockedMonitors && !isObjectMonitorUsageSupported()) {

            throw new UnsupportedOperationException(

                "Monitoring of Object Monitor Usage is not supported.");

        }

        if (lockedSynchronizers && !isSynchronizerUsageSupported()) {

            throw new UnsupportedOperationException(

                "Monitoring of Synchronizer Usage is not supported.");

        }

        return dumpThreads0(ids, lockedMonitors, lockedSynchronizers);

    }

    public ThreadInfo[] dumpAllThreads(boolean lockedMonitors, boolean lockedSynchronizers) {

        if (lockedMonitors && !isObjectMonitorUsageSupported()) {

            throw new UnsupportedOperationException(

                "Monitoring of Object Monitor Usage is not supported.");

        }

        if (lockedSynchronizers && !isSynchronizerUsageSupported()) {

            throw new UnsupportedOperationException(

                "Monitoring of Synchronizer Usage is not supported.");

        }

        return dumpThreads0(null, lockedMonitors, lockedSynchronizers);

    }

    // VM support where maxDepth == -1 to request entire stack dump

    private static native Thread[] getThreads();

    private static native void getThreadInfo0(long[] ids,

                                              int maxDepth,

                                              ThreadInfo[] result);

    private static native long getThreadTotalCpuTime0(long id);

    private static native long getThreadUserCpuTime0(long id);

    private static native void setThreadCpuTimeEnabled0(boolean enable);

    private static native void setThreadContentionMonitoringEnabled0(boolean enable);

    private static native Thread[] findMonitorDeadlockedThreads0();

    private static native Thread[] findDeadlockedThreads0();

    private static native void resetPeakThreadCount0();

    private static native ThreadInfo[] dumpThreads0(long[] ids,

                                                    boolean lockedMonitors,

                                                    boolean lockedSynchronizers);

    // tid == 0 to reset contention times for all threads

    private static native void resetContentionTimes0(long tid);

}