https://openjdk.java.net/ 
/*
 * Copyright (c) 2003, 2013, 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
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 */

package java.lang.management;

import javax.management.openmbean.CompositeData;
import sun.management.ManagementFactoryHelper;
import sun.management.ThreadInfoCompositeData;
import static java.lang.Thread.State.*;


Thread information. ThreadInfo contains the information
about a thread including:

General thread information


    
  
  • Thread ID.
    • 
  
  • Name of the thread.
    • 



Execution information


    
  
  • Thread state.
    • 
  
  • The object upon which the thread is blocked due to:
      
      
      
    • waiting to enter a synchronization block/method, or
      • 
      
    • waiting to be notified in a Object.wait method, or
      • 
      
    • parking due to a 
          LockSupport.park call.
      • 
      
    
  
    • 
  
  • The ID of the thread that owns the object
      that the thread is blocked.
    • 
  
  • Stack trace of the thread.
    • 
  
  • List of object monitors locked by the thread.
    • 
  
  • List of 
      ownable synchronizers locked by the thread.
    • 



Synchronization Statistics


    
  
  • The number of times that the thread has blocked for
      synchronization or waited for notification.
    • 
  
  • The accumulated elapsed time that the thread has blocked for synchronization or waited for notification since 
      thread contention monitoring was enabled. Some Java virtual machine implementation may not support this. The ThreadMXBean.isThreadContentionMonitoringSupported() method can be used to determine if a Java virtual machine supports this.
    • 



This thread information class is designed for use in monitoring of
the system, not for synchronization control.

MXBean Mapping

ThreadInfo is mapped to a CompositeData with attributes as specified in the from method. 
Author: Mandy Chung
See Also:
Since:  1.5
/**
 * Thread information. <tt>ThreadInfo</tt> contains the information
 * about a thread including:
 * <h3>General thread information</h3>
 * <ul>
 *   <li>Thread ID.</li>
 *   <li>Name of the thread.</li>
 * </ul>
 *
 * <h3>Execution information</h3>
 * <ul>
 *   <li>Thread state.</li>
 *   <li>The object upon which the thread is blocked due to:
 *       <ul>
 *       <li>waiting to enter a synchronization block/method, or</li>
 *       <li>waiting to be notified in a {@link Object#wait Object.wait} method,
 *           or</li>
 *       <li>parking due to a {@link java.util.concurrent.locks.LockSupport#park
 *           LockSupport.park} call.</li>
 *       </ul>
 *   </li>
 *   <li>The ID of the thread that owns the object
 *       that the thread is blocked.</li>
 *   <li>Stack trace of the thread.</li>
 *   <li>List of object monitors locked by the thread.</li>
 *   <li>List of <a href="LockInfo.html#OwnableSynchronizer">
 *       ownable synchronizers</a> locked by the thread.</li>
 * </ul>
 *
 * <h4><a name="SyncStats">Synchronization Statistics</a></h4>
 * <ul>
 *   <li>The number of times that the thread has blocked for
 *       synchronization or waited for notification.</li>
 *   <li>The accumulated elapsed time that the thread has blocked
 *       for synchronization or waited for notification
 *       since {@link ThreadMXBean#setThreadContentionMonitoringEnabled
 *       thread contention monitoring}
 *       was enabled. Some Java virtual machine implementation
 *       may not support this.  The
 *       {@link ThreadMXBean#isThreadContentionMonitoringSupported()}
 *       method can be used to determine if a Java virtual machine
 *       supports this.</li>
 * </ul>
 *
 * <p>This thread information class is designed for use in monitoring of
 * the system, not for synchronization control.
 *
 * <h4>MXBean Mapping</h4>
 * <tt>ThreadInfo</tt> is mapped to a {@link CompositeData CompositeData}
 * with attributes as specified in
 * the {@link #from from} method.
 *
 * @see ThreadMXBean#getThreadInfo
 * @see ThreadMXBean#dumpAllThreads
 *
 * @author  Mandy Chung
 * @since   1.5
 */

public class ThreadInfo {
    private String       threadName;
    private long         threadId;
    private long         blockedTime;
    private long         blockedCount;
    private long         waitedTime;
    private long         waitedCount;
    private LockInfo     lock;
    private String       lockName;
    private long         lockOwnerId;
    private String       lockOwnerName;
    private boolean      inNative;
    private boolean      suspended;
    private Thread.State threadState;
    private StackTraceElement[] stackTrace;
    private MonitorInfo[]       lockedMonitors;
    private LockInfo[]          lockedSynchronizers;

    private static MonitorInfo[] EMPTY_MONITORS = new MonitorInfo[0];
    private static LockInfo[] EMPTY_SYNCS = new LockInfo[0];

    
Constructor of ThreadInfo created by the JVM

Params:
  • t –             Thread
  • state –         Thread state
  • lockObj –       Object on which the thread is blocked
  • lockOwner –     the thread holding the lock
  • blockedCount –  Number of times blocked to enter a lock
  • blockedTime –   Approx time blocked to enter a lock
  • waitedCount –   Number of times waited on a lock
  • waitedTime –    Approx time waited on a lock
  • stackTrace –    Thread stack trace
/**
     * Constructor of ThreadInfo created by the JVM
     *
     * @param t             Thread
     * @param state         Thread state
     * @param lockObj       Object on which the thread is blocked
     * @param lockOwner     the thread holding the lock
     * @param blockedCount  Number of times blocked to enter a lock
     * @param blockedTime   Approx time blocked to enter a lock
     * @param waitedCount   Number of times waited on a lock
     * @param waitedTime    Approx time waited on a lock
     * @param stackTrace    Thread stack trace
     */
    private ThreadInfo(Thread t, int state, Object lockObj, Thread lockOwner,
                       long blockedCount, long blockedTime,
                       long waitedCount, long waitedTime,
                       StackTraceElement[] stackTrace) {
        initialize(t, state, lockObj, lockOwner,
                   blockedCount, blockedTime,
                   waitedCount, waitedTime, stackTrace,
                   EMPTY_MONITORS, EMPTY_SYNCS);
    }

    
Constructor of ThreadInfo created by the JVM for ThreadMXBean.getThreadInfo(long[], boolean, boolean) and ThreadMXBean.dumpAllThreads 
Params:
  • t –             Thread
  • state –         Thread state
  • lockObj –       Object on which the thread is blocked
  • lockOwner –     the thread holding the lock
  • blockedCount –  Number of times blocked to enter a lock
  • blockedTime –   Approx time blocked to enter a lock
  • waitedCount –   Number of times waited on a lock
  • waitedTime –    Approx time waited on a lock
  • stackTrace –    Thread stack trace
  • monitors –      List of locked monitors
  • stackDepths –   List of stack depths
  • synchronizers – List of locked synchronizers
/**
     * Constructor of ThreadInfo created by the JVM
     * for {@link ThreadMXBean#getThreadInfo(long[],boolean,boolean)}
     * and {@link ThreadMXBean#dumpAllThreads}
     *
     * @param t             Thread
     * @param state         Thread state
     * @param lockObj       Object on which the thread is blocked
     * @param lockOwner     the thread holding the lock
     * @param blockedCount  Number of times blocked to enter a lock
     * @param blockedTime   Approx time blocked to enter a lock
     * @param waitedCount   Number of times waited on a lock
     * @param waitedTime    Approx time waited on a lock
     * @param stackTrace    Thread stack trace
     * @param monitors      List of locked monitors
     * @param stackDepths   List of stack depths
     * @param synchronizers List of locked synchronizers
     */
    private ThreadInfo(Thread t, int state, Object lockObj, Thread lockOwner,
                       long blockedCount, long blockedTime,
                       long waitedCount, long waitedTime,
                       StackTraceElement[] stackTrace,
                       Object[] monitors,
                       int[] stackDepths,
                       Object[] synchronizers) {
        int numMonitors = (monitors == null ? 0 : monitors.length);
        MonitorInfo[] lockedMonitors;
        if (numMonitors == 0) {
            lockedMonitors = EMPTY_MONITORS;
        } else {
            lockedMonitors = new MonitorInfo[numMonitors];
            for (int i = 0; i < numMonitors; i++) {
                Object lock = monitors[i];
                String className = lock.getClass().getName();
                int identityHashCode = System.identityHashCode(lock);
                int depth = stackDepths[i];
                StackTraceElement ste = (depth >= 0 ? stackTrace[depth]
                                                    : null);
                lockedMonitors[i] = new MonitorInfo(className,
                                                    identityHashCode,
                                                    depth,
                                                    ste);
            }
        }

        int numSyncs = (synchronizers == null ? 0 : synchronizers.length);
        LockInfo[] lockedSynchronizers;
        if (numSyncs == 0) {
            lockedSynchronizers = EMPTY_SYNCS;
        } else {
            lockedSynchronizers = new LockInfo[numSyncs];
            for (int i = 0; i < numSyncs; i++) {
                Object lock = synchronizers[i];
                String className = lock.getClass().getName();
                int identityHashCode = System.identityHashCode(lock);
                lockedSynchronizers[i] = new LockInfo(className,
                                                      identityHashCode);
            }
        }

        initialize(t, state, lockObj, lockOwner,
                   blockedCount, blockedTime,
                   waitedCount, waitedTime, stackTrace,
                   lockedMonitors, lockedSynchronizers);
    }

    
Initialize ThreadInfo object

Params:
  • t –             Thread
  • state –         Thread state
  • lockObj –       Object on which the thread is blocked
  • lockOwner –     the thread holding the lock
  • blockedCount –  Number of times blocked to enter a lock
  • blockedTime –   Approx time blocked to enter a lock
  • waitedCount –   Number of times waited on a lock
  • waitedTime –    Approx time waited on a lock
  • stackTrace –    Thread stack trace
  • lockedMonitors – List of locked monitors
  • lockedSynchronizers – List of locked synchronizers
/**
     * Initialize ThreadInfo object
     *
     * @param t             Thread
     * @param state         Thread state
     * @param lockObj       Object on which the thread is blocked
     * @param lockOwner     the thread holding the lock
     * @param blockedCount  Number of times blocked to enter a lock
     * @param blockedTime   Approx time blocked to enter a lock
     * @param waitedCount   Number of times waited on a lock
     * @param waitedTime    Approx time waited on a lock
     * @param stackTrace    Thread stack trace
     * @param lockedMonitors List of locked monitors
     * @param lockedSynchronizers List of locked synchronizers
     */
    private void initialize(Thread t, int state, Object lockObj, Thread lockOwner,
                            long blockedCount, long blockedTime,
                            long waitedCount, long waitedTime,
                            StackTraceElement[] stackTrace,
                            MonitorInfo[] lockedMonitors,
                            LockInfo[] lockedSynchronizers) {
        this.threadId = t.getId();
        this.threadName = t.getName();
        this.threadState = ManagementFactoryHelper.toThreadState(state);
        this.suspended = ManagementFactoryHelper.isThreadSuspended(state);
        this.inNative = ManagementFactoryHelper.isThreadRunningNative(state);
        this.blockedCount = blockedCount;
        this.blockedTime = blockedTime;
        this.waitedCount = waitedCount;
        this.waitedTime = waitedTime;

        if (lockObj == null) {
            this.lock = null;
            this.lockName = null;
        } else {
            this.lock = new LockInfo(lockObj);
            this.lockName =
                lock.getClassName() + '@' +
                    Integer.toHexString(lock.getIdentityHashCode());
        }
        if (lockOwner == null) {
            this.lockOwnerId = -1;
            this.lockOwnerName = null;
        } else {
            this.lockOwnerId = lockOwner.getId();
            this.lockOwnerName = lockOwner.getName();
        }
        if (stackTrace == null) {
            this.stackTrace = NO_STACK_TRACE;
        } else {
            this.stackTrace = stackTrace;
        }
        this.lockedMonitors = lockedMonitors;
        this.lockedSynchronizers = lockedSynchronizers;
    }

    /*
     * Constructs a <tt>ThreadInfo</tt> object from a
     * {@link CompositeData CompositeData}.
     */
    private ThreadInfo(CompositeData cd) {
        ThreadInfoCompositeData ticd = ThreadInfoCompositeData.getInstance(cd);

        threadId = ticd.threadId();
        threadName = ticd.threadName();
        blockedTime = ticd.blockedTime();
        blockedCount = ticd.blockedCount();
        waitedTime = ticd.waitedTime();
        waitedCount = ticd.waitedCount();
        lockName = ticd.lockName();
        lockOwnerId = ticd.lockOwnerId();
        lockOwnerName = ticd.lockOwnerName();
        threadState = ticd.threadState();
        suspended = ticd.suspended();
        inNative = ticd.inNative();
        stackTrace = ticd.stackTrace();

        // 6.0 attributes
        if (ticd.isCurrentVersion()) {
            lock = ticd.lockInfo();
            lockedMonitors = ticd.lockedMonitors();
            lockedSynchronizers = ticd.lockedSynchronizers();
        } else {
            // lockInfo is a new attribute added in 1.6 ThreadInfo
            // If cd is a 5.0 version, construct the LockInfo object
            //  from the lockName value.
            if (lockName != null) {
                String result[] = lockName.split("@");
                if (result.length == 2) {
                    int identityHashCode = Integer.parseInt(result[1], 16);
                    lock = new LockInfo(result[0], identityHashCode);
                } else {
                    assert result.length == 2;
                    lock = null;
                }
            } else {
                lock = null;
            }
            lockedMonitors = EMPTY_MONITORS;
            lockedSynchronizers = EMPTY_SYNCS;
        }
    }

    
Returns the ID of the thread associated with this ThreadInfo.

Returns:the ID of the associated thread.
/**
     * Returns the ID of the thread associated with this <tt>ThreadInfo</tt>.
     *
     * @return the ID of the associated thread.
     */
    public long getThreadId() {
        return threadId;
    }

    
Returns the name of the thread associated with this ThreadInfo.

Returns:the name of the associated thread.
/**
     * Returns the name of the thread associated with this <tt>ThreadInfo</tt>.
     *
     * @return the name of the associated thread.
     */
    public String getThreadName() {
        return threadName;
    }

    
Returns the state of the thread associated with this ThreadInfo.

Returns:Thread.State of the associated thread.
/**
     * Returns the state of the thread associated with this <tt>ThreadInfo</tt>.
     *
     * @return <tt>Thread.State</tt> of the associated thread.
     */
    public Thread.State getThreadState() {
         return threadState;
    }

    
Returns the approximate accumulated elapsed time (in milliseconds)
that the thread associated with this ThreadInfo has blocked to enter or reenter a monitor since thread contention monitoring is enabled. I.e. the total accumulated time the thread has been in the BLOCKED state since thread contention monitoring was last enabled. This method returns -1 if thread contention monitoring
is disabled.

The Java virtual machine may measure the time with a high
resolution timer.  This statistic is reset when
the thread contention monitoring is reenabled.

Throws:
See Also:
Returns:the approximate accumulated elapsed time in milliseconds
that a thread entered the BLOCKED state;
-1 if thread contention monitoring is disabled.
/**
     * Returns the approximate accumulated elapsed time (in milliseconds)
     * that the thread associated with this <tt>ThreadInfo</tt>
     * has blocked to enter or reenter a monitor
     * since thread contention monitoring is enabled.
     * I.e. the total accumulated time the thread has been in the
     * {@link java.lang.Thread.State#BLOCKED BLOCKED} state since thread
     * contention monitoring was last enabled.
     * This method returns <tt>-1</tt> if thread contention monitoring
     * is disabled.
     *
     * <p>The Java virtual machine may measure the time with a high
     * resolution timer.  This statistic is reset when
     * the thread contention monitoring is reenabled.
     *
     * @return the approximate accumulated elapsed time in milliseconds
     * that a thread entered the <tt>BLOCKED</tt> state;
     * <tt>-1</tt> if thread contention monitoring is disabled.
     *
     * @throws java.lang.UnsupportedOperationException if the Java
     * virtual machine does not support this operation.
     *
     * @see ThreadMXBean#isThreadContentionMonitoringSupported
     * @see ThreadMXBean#setThreadContentionMonitoringEnabled
     */
    public long getBlockedTime() {
        return blockedTime;
    }

    
Returns the total number of times that
the thread associated with this ThreadInfo blocked to enter or reenter a monitor. I.e. the number of times a thread has been in the BLOCKED state. 
Returns:the total number of times that the thread
entered the BLOCKED state.
/**
     * Returns the total number of times that
     * the thread associated with this <tt>ThreadInfo</tt>
     * blocked to enter or reenter a monitor.
     * I.e. the number of times a thread has been in the
     * {@link java.lang.Thread.State#BLOCKED BLOCKED} state.
     *
     * @return the total number of times that the thread
     * entered the <tt>BLOCKED</tt> state.
     */
    public long getBlockedCount() {
        return blockedCount;
    }

    
Returns the approximate accumulated elapsed time (in milliseconds)
that the thread associated with this ThreadInfo has waited for notification since thread contention monitoring is enabled. I.e. the total accumulated time the thread has been in the WAITING or TIMED_WAITING state since thread contention monitoring is enabled. This method returns -1 if thread contention monitoring
is disabled.

The Java virtual machine may measure the time with a high
resolution timer.  This statistic is reset when
the thread contention monitoring is reenabled.

Throws:
See Also:
Returns:the approximate accumulated elapsed time in milliseconds
that a thread has been in the WAITING or
TIMED_WAITING state;
-1 if thread contention monitoring is disabled.
/**
     * Returns the approximate accumulated elapsed time (in milliseconds)
     * that the thread associated with this <tt>ThreadInfo</tt>
     * has waited for notification
     * since thread contention monitoring is enabled.
     * I.e. the total accumulated time the thread has been in the
     * {@link java.lang.Thread.State#WAITING WAITING}
     * or {@link java.lang.Thread.State#TIMED_WAITING TIMED_WAITING} state
     * since thread contention monitoring is enabled.
     * This method returns <tt>-1</tt> if thread contention monitoring
     * is disabled.
     *
     * <p>The Java virtual machine may measure the time with a high
     * resolution timer.  This statistic is reset when
     * the thread contention monitoring is reenabled.
     *
     * @return the approximate accumulated elapsed time in milliseconds
     * that a thread has been in the <tt>WAITING</tt> or
     * <tt>TIMED_WAITING</tt> state;
     * <tt>-1</tt> if thread contention monitoring is disabled.
     *
     * @throws java.lang.UnsupportedOperationException if the Java
     * virtual machine does not support this operation.
     *
     * @see ThreadMXBean#isThreadContentionMonitoringSupported
     * @see ThreadMXBean#setThreadContentionMonitoringEnabled
     */
    public long getWaitedTime() {
        return waitedTime;
    }

    
Returns the total number of times that
the thread associated with this ThreadInfo waited for notification. I.e. the number of times that a thread has been in the WAITING or TIMED_WAITING state. 
Returns:the total number of times that the thread
was in the WAITING or TIMED_WAITING state.
/**
     * Returns the total number of times that
     * the thread associated with this <tt>ThreadInfo</tt>
     * waited for notification.
     * I.e. the number of times that a thread has been
     * in the {@link java.lang.Thread.State#WAITING WAITING}
     * or {@link java.lang.Thread.State#TIMED_WAITING TIMED_WAITING} state.
     *
     * @return the total number of times that the thread
     * was in the <tt>WAITING</tt> or <tt>TIMED_WAITING</tt> state.
     */
    public long getWaitedCount() {
        return waitedCount;
    }

    
Returns the LockInfo of an object for which
the thread associated with this ThreadInfo
is blocked waiting.
A thread can be blocked waiting for one of the following:


This method returns null if the thread is not in any of
the above conditions.

Returns:LockInfo of an object for which the thread
        is blocked waiting if any; null otherwise.
Since:1.6
/**
     * Returns the <tt>LockInfo</tt> of an object for which
     * the thread associated with this <tt>ThreadInfo</tt>
     * is blocked waiting.
     * A thread can be blocked waiting for one of the following:
     * <ul>
     * <li>an object monitor to be acquired for entering or reentering
     *     a synchronization block/method.
     *     <br>The thread is in the {@link java.lang.Thread.State#BLOCKED BLOCKED}
     *     state waiting to enter the <tt>synchronized</tt> statement
     *     or method.
     *     <p></li>
     * <li>an object monitor to be notified by another thread.
     *     <br>The thread is in the {@link java.lang.Thread.State#WAITING WAITING}
     *     or {@link java.lang.Thread.State#TIMED_WAITING TIMED_WAITING} state
     *     due to a call to the {@link Object#wait Object.wait} method.
     *     <p></li>
     * <li>a synchronization object responsible for the thread parking.
     *     <br>The thread is in the {@link java.lang.Thread.State#WAITING WAITING}
     *     or {@link java.lang.Thread.State#TIMED_WAITING TIMED_WAITING} state
     *     due to a call to the
     *     {@link java.util.concurrent.locks.LockSupport#park(Object)
     *     LockSupport.park} method.  The synchronization object
     *     is the object returned from
     *     {@link java.util.concurrent.locks.LockSupport#getBlocker
     *     LockSupport.getBlocker} method. Typically it is an
     *     <a href="LockInfo.html#OwnableSynchronizer"> ownable synchronizer</a>
     *     or a {@link java.util.concurrent.locks.Condition Condition}.</li>
     * </ul>
     *
     * <p>This method returns <tt>null</tt> if the thread is not in any of
     * the above conditions.
     *
     * @return <tt>LockInfo</tt> of an object for which the thread
     *         is blocked waiting if any; <tt>null</tt> otherwise.
     * @since 1.6
     */
    public LockInfo getLockInfo() {
        return lock;
    }

    
Returns the string representation of an object for which the thread associated with this ThreadInfo is blocked waiting.
This method is equivalent to calling:



getLockInfo().toString()



This method will return null if this thread is not blocked
waiting for any object or if the object is not owned by any thread.

See Also:
Returns:the string representation of the object on which
the thread is blocked if any;
null otherwise.
/**
     * Returns the {@link LockInfo#toString string representation}
     * of an object for which the thread associated with this
     * <tt>ThreadInfo</tt> is blocked waiting.
     * This method is equivalent to calling:
     * <blockquote>
     * <pre>
     * getLockInfo().toString()
     * </pre></blockquote>
     *
     * <p>This method will return <tt>null</tt> if this thread is not blocked
     * waiting for any object or if the object is not owned by any thread.
     *
     * @return the string representation of the object on which
     * the thread is blocked if any;
     * <tt>null</tt> otherwise.
     *
     * @see #getLockInfo
     */
    public String getLockName() {
        return lockName;
    }

    
Returns the ID of the thread which owns the object
for which the thread associated with this ThreadInfo
is blocked waiting.
This method will return -1 if this thread is not blocked
waiting for any object or if the object is not owned by any thread.

See Also:
Returns:the thread ID of the owner thread of the object
this thread is blocked on;
-1 if this thread is not blocked
or if the object is not owned by any thread.
/**
     * Returns the ID of the thread which owns the object
     * for which the thread associated with this <tt>ThreadInfo</tt>
     * is blocked waiting.
     * This method will return <tt>-1</tt> if this thread is not blocked
     * waiting for any object or if the object is not owned by any thread.
     *
     * @return the thread ID of the owner thread of the object
     * this thread is blocked on;
     * <tt>-1</tt> if this thread is not blocked
     * or if the object is not owned by any thread.
     *
     * @see #getLockInfo
     */
    public long getLockOwnerId() {
        return lockOwnerId;
    }

    
Returns the name of the thread which owns the object
for which the thread associated with this ThreadInfo
is blocked waiting.
This method will return null if this thread is not blocked
waiting for any object or if the object is not owned by any thread.

See Also:
Returns:the name of the thread that owns the object
this thread is blocked on;
null if this thread is not blocked
or if the object is not owned by any thread.
/**
     * Returns the name of the thread which owns the object
     * for which the thread associated with this <tt>ThreadInfo</tt>
     * is blocked waiting.
     * This method will return <tt>null</tt> if this thread is not blocked
     * waiting for any object or if the object is not owned by any thread.
     *
     * @return the name of the thread that owns the object
     * this thread is blocked on;
     * <tt>null</tt> if this thread is not blocked
     * or if the object is not owned by any thread.
     *
     * @see #getLockInfo
     */
    public String getLockOwnerName() {
        return lockOwnerName;
    }

    
Returns the stack trace of the thread
associated with this ThreadInfo.
If no stack trace was requested for this thread info, this method
will return a zero-length array.
If the returned array is of non-zero length then the first element of
the array represents the top of the stack, which is the most recent
method invocation in the sequence.  The last element of the array
represents the bottom of the stack, which is the least recent method
invocation in the sequence.

Some Java virtual machines may, under some circumstances, omit one
or more stack frames from the stack trace.  In the extreme case,
a virtual machine that has no stack trace information concerning
the thread associated with this ThreadInfo
is permitted to return a zero-length array from this method.

Returns:an array of StackTraceElement objects of the thread.
/**
     * Returns the stack trace of the thread
     * associated with this <tt>ThreadInfo</tt>.
     * If no stack trace was requested for this thread info, this method
     * will return a zero-length array.
     * If the returned array is of non-zero length then the first element of
     * the array represents the top of the stack, which is the most recent
     * method invocation in the sequence.  The last element of the array
     * represents the bottom of the stack, which is the least recent method
     * invocation in the sequence.
     *
     * <p>Some Java virtual machines may, under some circumstances, omit one
     * or more stack frames from the stack trace.  In the extreme case,
     * a virtual machine that has no stack trace information concerning
     * the thread associated with this <tt>ThreadInfo</tt>
     * is permitted to return a zero-length array from this method.
     *
     * @return an array of <tt>StackTraceElement</tt> objects of the thread.
     */
    public StackTraceElement[] getStackTrace() {
        return stackTrace;
    }

    
Tests if the thread associated with this ThreadInfo
is suspended.  This method returns true if Thread.suspend has been called. 
Returns:true if the thread is suspended;
        false otherwise.
/**
     * Tests if the thread associated with this <tt>ThreadInfo</tt>
     * is suspended.  This method returns <tt>true</tt> if
     * {@link Thread#suspend} has been called.
     *
     * @return <tt>true</tt> if the thread is suspended;
     *         <tt>false</tt> otherwise.
     */
    public boolean isSuspended() {
         return suspended;
    }

    
Tests if the thread associated with this ThreadInfo
is executing native code via the Java Native Interface (JNI).
The JNI native code does not include
the virtual machine support code or the compiled native
code generated by the virtual machine.

Returns:true if the thread is executing native code;
        false otherwise.
/**
     * Tests if the thread associated with this <tt>ThreadInfo</tt>
     * is executing native code via the Java Native Interface (JNI).
     * The JNI native code does not include
     * the virtual machine support code or the compiled native
     * code generated by the virtual machine.
     *
     * @return <tt>true</tt> if the thread is executing native code;
     *         <tt>false</tt> otherwise.
     */
    public boolean isInNative() {
         return inNative;
    }

    
Returns a string representation of this thread info. The format of this string depends on the implementation. The returned string will typically include the thread name, the thread ID, its state, and a stack trace if any. 
Returns:a string representation of this thread info.
/**
     * Returns a string representation of this thread info.
     * The format of this string depends on the implementation.
     * The returned string will typically include
     * the {@linkplain #getThreadName thread name},
     * the {@linkplain #getThreadId thread ID},
     * its {@linkplain #getThreadState state},
     * and a {@linkplain #getStackTrace stack trace} if any.
     *
     * @return a string representation of this thread info.
     */
    public String toString() {
        StringBuilder sb = new StringBuilder("\"" + getThreadName() + "\"" +
                                             " Id=" + getThreadId() + " " +
                                             getThreadState());
        if (getLockName() != null) {
            sb.append(" on " + getLockName());
        }
        if (getLockOwnerName() != null) {
            sb.append(" owned by \"" + getLockOwnerName() +
                      "\" Id=" + getLockOwnerId());
        }
        if (isSuspended()) {
            sb.append(" (suspended)");
        }
        if (isInNative()) {
            sb.append(" (in native)");
        }
        sb.append('\n');
        int i = 0;
        for (; i < stackTrace.length && i < MAX_FRAMES; i++) {
            StackTraceElement ste = stackTrace[i];
            sb.append("\tat " + ste.toString());
            sb.append('\n');
            if (i == 0 && getLockInfo() != null) {
                Thread.State ts = getThreadState();
                switch (ts) {
                    case BLOCKED:
                        sb.append("\t-  blocked on " + getLockInfo());
                        sb.append('\n');
                        break;
                    case WAITING:
                        sb.append("\t-  waiting on " + getLockInfo());
                        sb.append('\n');
                        break;
                    case TIMED_WAITING:
                        sb.append("\t-  waiting on " + getLockInfo());
                        sb.append('\n');
                        break;
                    default:
                }
            }

            for (MonitorInfo mi : lockedMonitors) {
                if (mi.getLockedStackDepth() == i) {
                    sb.append("\t-  locked " + mi);
                    sb.append('\n');
                }
            }
       }
       if (i < stackTrace.length) {
           sb.append("\t...");
           sb.append('\n');
       }

       LockInfo[] locks = getLockedSynchronizers();
       if (locks.length > 0) {
           sb.append("\n\tNumber of locked synchronizers = " + locks.length);
           sb.append('\n');
           for (LockInfo li : locks) {
               sb.append("\t- " + li);
               sb.append('\n');
           }
       }
       sb.append('\n');
       return sb.toString();
    }
    private static final int MAX_FRAMES = 8;

    
Returns a ThreadInfo object represented by the
given CompositeData.
The given CompositeData must contain the following attributes
unless otherwise specified below:






  Attribute Name
  Type




  threadId
  java.lang.Long




  threadName
  java.lang.String




  threadState
  java.lang.String




  suspended
  java.lang.Boolean




  inNative
  java.lang.Boolean




  blockedCount
  java.lang.Long




  blockedTime
  java.lang.Long




  waitedCount
  java.lang.Long




  waitedTime
  java.lang.Long




  lockInfo
  javax.management.openmbean.CompositeData - the mapped type for LockInfo as specified in the LockInfo.from method. 

      If cd does not contain this attribute,
      the LockInfo object will be constructed from
      the value of the lockName attribute. 





  lockName
  java.lang.String




  lockOwnerId
  java.lang.Long




  lockOwnerName
  java.lang.String




  stackTrace
  javax.management.openmbean.CompositeData[]
      

      Each element is a CompositeData representing
      StackTraceElement containing the following attributes:
      

      

      

        Attribute Name
        Type
      

      

        className
        java.lang.String
      

      

        methodName
        java.lang.String
      

      

        fileName
        java.lang.String
      

      

        lineNumber
        java.lang.Integer
      

      

        nativeMethod
        java.lang.Boolean
      

      

      

  		




  lockedMonitors
  javax.management.openmbean.CompositeData[] whose element type is the mapped type for MonitorInfo as specified in the Monitor.from method. 

      If cd does not contain this attribute,
      this attribute will be set to an empty array. 





  lockedSynchronizers
  javax.management.openmbean.CompositeData[] whose element type is the mapped type for LockInfo as specified in the LockInfo.from method. 

      If cd does not contain this attribute,
      this attribute will be set to an empty array. 








Params:
  • cd – CompositeData representing a ThreadInfo
Throws:
Returns:a ThreadInfo object represented
        by cd if cd is not null;
        null otherwise.
/**
     * Returns a <tt>ThreadInfo</tt> object represented by the
     * given <tt>CompositeData</tt>.
     * The given <tt>CompositeData</tt> must contain the following attributes
     * unless otherwise specified below:
     * <blockquote>
     * <table border summary="The attributes and their types the given CompositeData contains">
     * <tr>
     *   <th align=left>Attribute Name</th>
     *   <th align=left>Type</th>
     * </tr>
     * <tr>
     *   <td>threadId</td>
     *   <td><tt>java.lang.Long</tt></td>
     * </tr>
     * <tr>
     *   <td>threadName</td>
     *   <td><tt>java.lang.String</tt></td>
     * </tr>
     * <tr>
     *   <td>threadState</td>
     *   <td><tt>java.lang.String</tt></td>
     * </tr>
     * <tr>
     *   <td>suspended</td>
     *   <td><tt>java.lang.Boolean</tt></td>
     * </tr>
     * <tr>
     *   <td>inNative</td>
     *   <td><tt>java.lang.Boolean</tt></td>
     * </tr>
     * <tr>
     *   <td>blockedCount</td>
     *   <td><tt>java.lang.Long</tt></td>
     * </tr>
     * <tr>
     *   <td>blockedTime</td>
     *   <td><tt>java.lang.Long</tt></td>
     * </tr>
     * <tr>
     *   <td>waitedCount</td>
     *   <td><tt>java.lang.Long</tt></td>
     * </tr>
     * <tr>
     *   <td>waitedTime</td>
     *   <td><tt>java.lang.Long</tt></td>
     * </tr>
     * <tr>
     *   <td>lockInfo</td>
     *   <td><tt>javax.management.openmbean.CompositeData</tt>
     *       - the mapped type for {@link LockInfo} as specified in the
     *         {@link LockInfo#from} method.
     *       <p>
     *       If <tt>cd</tt> does not contain this attribute,
     *       the <tt>LockInfo</tt> object will be constructed from
     *       the value of the <tt>lockName</tt> attribute. </td>
     * </tr>
     * <tr>
     *   <td>lockName</td>
     *   <td><tt>java.lang.String</tt></td>
     * </tr>
     * <tr>
     *   <td>lockOwnerId</td>
     *   <td><tt>java.lang.Long</tt></td>
     * </tr>
     * <tr>
     *   <td>lockOwnerName</td>
     *   <td><tt>java.lang.String</tt></td>
     * </tr>
     * <tr>
     *   <td><a name="StackTrace">stackTrace</a></td>
     *   <td><tt>javax.management.openmbean.CompositeData[]</tt>
     *       <p>
     *       Each element is a <tt>CompositeData</tt> representing
     *       StackTraceElement containing the following attributes:
     *       <blockquote>
     *       <table cellspacing=1 cellpadding=0 summary="The attributes and their types the given CompositeData contains">
     *       <tr>
     *         <th align=left>Attribute Name</th>
     *         <th align=left>Type</th>
     *       </tr>
     *       <tr>
     *         <td>className</td>
     *         <td><tt>java.lang.String</tt></td>
     *       </tr>
     *       <tr>
     *         <td>methodName</td>
     *         <td><tt>java.lang.String</tt></td>
     *       </tr>
     *       <tr>
     *         <td>fileName</td>
     *         <td><tt>java.lang.String</tt></td>
     *       </tr>
     *       <tr>
     *         <td>lineNumber</td>
     *         <td><tt>java.lang.Integer</tt></td>
     *       </tr>
     *       <tr>
     *         <td>nativeMethod</td>
     *         <td><tt>java.lang.Boolean</tt></td>
     *       </tr>
     *       </table>
     *       </blockquote>
     *   </td>
     * </tr>
     * <tr>
     *   <td>lockedMonitors</td>
     *   <td><tt>javax.management.openmbean.CompositeData[]</tt>
     *       whose element type is the mapped type for
     *       {@link MonitorInfo} as specified in the
     *       {@link MonitorInfo#from Monitor.from} method.
     *       <p>
     *       If <tt>cd</tt> does not contain this attribute,
     *       this attribute will be set to an empty array. </td>
     * </tr>
     * <tr>
     *   <td>lockedSynchronizers</td>
     *   <td><tt>javax.management.openmbean.CompositeData[]</tt>
     *       whose element type is the mapped type for
     *       {@link LockInfo} as specified in the {@link LockInfo#from} method.
     *       <p>
     *       If <tt>cd</tt> does not contain this attribute,
     *       this attribute will be set to an empty array. </td>
     * </tr>
     * </table>
     * </blockquote>
     *
     * @param cd <tt>CompositeData</tt> representing a <tt>ThreadInfo</tt>
     *
     * @throws IllegalArgumentException if <tt>cd</tt> does not
     *   represent a <tt>ThreadInfo</tt> with the attributes described
     *   above.
     *
     * @return a <tt>ThreadInfo</tt> object represented
     *         by <tt>cd</tt> if <tt>cd</tt> is not <tt>null</tt>;
     *         <tt>null</tt> otherwise.
     */
    public static ThreadInfo from(CompositeData cd) {
        if (cd == null) {
            return null;
        }

        if (cd instanceof ThreadInfoCompositeData) {
            return ((ThreadInfoCompositeData) cd).getThreadInfo();
        } else {
            return new ThreadInfo(cd);
        }
    }

    
Returns an array of MonitorInfo objects, each of which represents an object monitor currently locked by the thread associated with this ThreadInfo.
If no locked monitor was requested for this thread info or
no monitor is locked by the thread, this method
will return a zero-length array.

Returns:an array of MonitorInfo objects representing
        the object monitors locked by the thread.
Since:1.6
/**
     * Returns an array of {@link MonitorInfo} objects, each of which
     * represents an object monitor currently locked by the thread
     * associated with this <tt>ThreadInfo</tt>.
     * If no locked monitor was requested for this thread info or
     * no monitor is locked by the thread, this method
     * will return a zero-length array.
     *
     * @return an array of <tt>MonitorInfo</tt> objects representing
     *         the object monitors locked by the thread.
     *
     * @since 1.6
     */
    public MonitorInfo[] getLockedMonitors() {
        return lockedMonitors;
    }

    
Returns an array of LockInfo objects, each of which represents an ownable
synchronizer currently locked by the thread associated with
this ThreadInfo.  If no locked synchronizer was
requested for this thread info or no synchronizer is locked by
the thread, this method will return a zero-length array.

Returns:an array of LockInfo objects representing
        the ownable synchronizers locked by the thread.
Since:1.6
/**
     * Returns an array of {@link LockInfo} objects, each of which
     * represents an <a href="LockInfo.html#OwnableSynchronizer">ownable
     * synchronizer</a> currently locked by the thread associated with
     * this <tt>ThreadInfo</tt>.  If no locked synchronizer was
     * requested for this thread info or no synchronizer is locked by
     * the thread, this method will return a zero-length array.
     *
     * @return an array of <tt>LockInfo</tt> objects representing
     *         the ownable synchronizers locked by the thread.
     *
     * @since 1.6
     */
    public LockInfo[] getLockedSynchronizers() {
        return lockedSynchronizers;
    }

    private static final StackTraceElement[] NO_STACK_TRACE =
        new StackTraceElement[0];
}