| /* |
| * Copyright (c) 2003, 2008, 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 |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package java.lang.management; |
| |
| import java.util.Map; |
| |
| /** |
| * The management interface for the thread system of |
| * the Java virtual machine. |
| * |
| * <p> A Java virtual machine has a single instance of the implementation |
| * class of this interface. This instance implementing this interface is |
| * an <a href="ManagementFactory.html#MXBean">MXBean</a> |
| * that can be obtained by calling |
| * the {@link ManagementFactory#getThreadMXBean} method or |
| * from the {@link ManagementFactory#getPlatformMBeanServer |
| * platform <tt>MBeanServer</tt>} method. |
| * |
| * <p>The <tt>ObjectName</tt> for uniquely identifying the MXBean for |
| * the thread system within an MBeanServer is: |
| * <blockquote> |
| * {@link ManagementFactory#THREAD_MXBEAN_NAME |
| * <tt>java.lang:type=Threading</tt>} |
| * </blockquote> |
| * |
| * It can be obtained by calling the |
| * {@link PlatformManagedObject#getObjectName} method. |
| * |
| * <h4>Thread ID</h4> |
| * Thread ID is a positive long value returned by calling the |
| * {@link java.lang.Thread#getId} method for a thread. |
| * The thread ID is unique during its lifetime. When a thread |
| * is terminated, this thread ID may be reused. |
| * |
| * <p> Some methods in this interface take a thread ID or an array |
| * of thread IDs as the input parameter and return per-thread information. |
| * |
| * <h4>Thread CPU time</h4> |
| * A Java virtual machine implementation may support measuring |
| * the CPU time for the current thread, for any thread, or for no threads. |
| * |
| * <p> |
| * The {@link #isThreadCpuTimeSupported} method can be used to determine |
| * if a Java virtual machine supports measuring of the CPU time for any |
| * thread. The {@link #isCurrentThreadCpuTimeSupported} method can |
| * be used to determine if a Java virtual machine supports measuring of |
| * the CPU time for the current thread. |
| * A Java virtual machine implementation that supports CPU time measurement |
| * for any thread will also support that for the current thread. |
| * |
| * <p> The CPU time provided by this interface has nanosecond precision |
| * but not necessarily nanosecond accuracy. |
| * |
| * <p> |
| * A Java virtual machine may disable CPU time measurement |
| * by default. |
| * The {@link #isThreadCpuTimeEnabled} and {@link #setThreadCpuTimeEnabled} |
| * methods can be used to test if CPU time measurement is enabled |
| * and to enable/disable this support respectively. |
| * Enabling thread CPU measurement could be expensive in some |
| * Java virtual machine implementations. |
| * |
| * <h4>Thread Contention Monitoring</h4> |
| * Some Java virtual machines may support thread contention monitoring. |
| * When thread contention monitoring is enabled, the accumulated elapsed |
| * time that the thread has blocked for synchronization or waited for |
| * notification will be collected and returned in the |
| * <a href="ThreadInfo.html#SyncStats"><tt>ThreadInfo</tt></a> object. |
| * <p> |
| * The {@link #isThreadContentionMonitoringSupported} method can be used to |
| * determine if a Java virtual machine supports thread contention monitoring. |
| * The thread contention monitoring is disabled by default. The |
| * {@link #setThreadContentionMonitoringEnabled} method can be used to enable |
| * thread contention monitoring. |
| * |
| * <h4>Synchronization Information and Deadlock Detection</h4> |
| * Some Java virtual machines may support monitoring of |
| * {@linkplain #isObjectMonitorUsageSupported object monitor usage} and |
| * {@linkplain #isSynchronizerUsageSupported ownable synchronizer usage}. |
| * The {@link #getThreadInfo(long[], boolean, boolean)} and |
| * {@link #dumpAllThreads} methods can be used to obtain the thread stack trace |
| * and synchronization information including which |
| * {@linkplain LockInfo <i>lock</i>} a thread is blocked to |
| * acquire or waiting on and which locks the thread currently owns. |
| * <p> |
| * The <tt>ThreadMXBean</tt> interface provides the |
| * {@link #findMonitorDeadlockedThreads} and |
| * {@link #findDeadlockedThreads} methods to find deadlocks in |
| * the running application. |
| * |
| * @see ManagementFactory#getPlatformMXBeans(Class) |
| * @see <a href="../../../javax/management/package-summary.html"> |
| * JMX Specification.</a> |
| * @see <a href="package-summary.html#examples"> |
| * Ways to Access MXBeans</a> |
| * |
| * @author Mandy Chung |
| * @since 1.5 |
| */ |
| |
| public interface ThreadMXBean extends PlatformManagedObject { |
| /** |
| * Returns the current number of live threads including both |
| * daemon and non-daemon threads. |
| * |
| * @return the current number of live threads. |
| */ |
| public int getThreadCount(); |
| |
| /** |
| * Returns the peak live thread count since the Java virtual machine |
| * started or peak was reset. |
| * |
| * @return the peak live thread count. |
| */ |
| public int getPeakThreadCount(); |
| |
| /** |
| * Returns the total number of threads created and also started |
| * since the Java virtual machine started. |
| * |
| * @return the total number of threads started. |
| */ |
| public long getTotalStartedThreadCount(); |
| |
| /** |
| * Returns the current number of live daemon threads. |
| * |
| * @return the current number of live daemon threads. |
| */ |
| public int getDaemonThreadCount(); |
| |
| /** |
| * Returns all live thread IDs. |
| * Some threads included in the returned array |
| * may have been terminated when this method returns. |
| * |
| * @return an array of <tt>long</tt>, each is a thread ID. |
| * |
| * @throws java.lang.SecurityException if a security manager |
| * exists and the caller does not have |
| * ManagementPermission("monitor"). |
| */ |
| public long[] getAllThreadIds(); |
| |
| /** |
| * Returns the thread info for a thread of the specified |
| * <tt>id</tt> with no stack trace. |
| * This method is equivalent to calling: |
| * <blockquote> |
| * {@link #getThreadInfo(long, int) getThreadInfo(id, 0);} |
| * </blockquote> |
| * |
| * <p> |
| * This method returns a <tt>ThreadInfo</tt> object representing |
| * the thread information for the thread of the specified ID. |
| * The stack trace, locked monitors, and locked synchronizers |
| * in the returned <tt>ThreadInfo</tt> object will |
| * be empty. |
| * |
| * If a thread of the given ID is not alive or does not exist, |
| * this method will return <tt>null</tt>. A thread is alive if |
| * it has been started and has not yet died. |
| * |
| * <p> |
| * <b>MBeanServer access</b>:<br> |
| * The mapped type of <tt>ThreadInfo</tt> is |
| * <tt>CompositeData</tt> with attributes as specified in the |
| * {@link ThreadInfo#from ThreadInfo.from} method. |
| * |
| * @param id the thread ID of the thread. Must be positive. |
| * |
| * @return a {@link ThreadInfo} object for the thread of the given ID |
| * with no stack trace, no locked monitor and no synchronizer info; |
| * <tt>null</tt> if the thread of the given ID is not alive or |
| * it does not exist. |
| * |
| * @throws IllegalArgumentException if <tt>id <= 0</tt>. |
| * @throws java.lang.SecurityException if a security manager |
| * exists and the caller does not have |
| * ManagementPermission("monitor"). |
| */ |
| public ThreadInfo getThreadInfo(long id); |
| |
| /** |
| * Returns the thread info for each thread |
| * whose ID is in the input array <tt>ids</tt> with no stack trace. |
| * This method is equivalent to calling: |
| * <blockquote><pre> |
| * {@link #getThreadInfo(long[], int) getThreadInfo}(ids, 0); |
| * </pre></blockquote> |
| * |
| * <p> |
| * This method returns an array of the <tt>ThreadInfo</tt> objects. |
| * The stack trace, locked monitors, and locked synchronizers |
| * in each <tt>ThreadInfo</tt> object will be empty. |
| * |
| * If a thread of a given ID is not alive or does not exist, |
| * the corresponding element in the returned array will |
| * contain <tt>null</tt>. A thread is alive if |
| * it has been started and has not yet died. |
| * |
| * <p> |
| * <b>MBeanServer access</b>:<br> |
| * The mapped type of <tt>ThreadInfo</tt> is |
| * <tt>CompositeData</tt> with attributes as specified in the |
| * {@link ThreadInfo#from ThreadInfo.from} method. |
| * |
| * @param ids an array of thread IDs. |
| * @return an array of the {@link ThreadInfo} objects, each containing |
| * information about a thread whose ID is in the corresponding |
| * element of the input array of IDs |
| * with no stack trace, no locked monitor and no synchronizer info. |
| * |
| * @throws IllegalArgumentException if any element in the input array |
| * <tt>ids</tt> is <tt><= 0</tt>. |
| * @throws java.lang.SecurityException if a security manager |
| * exists and the caller does not have |
| * ManagementPermission("monitor"). |
| */ |
| public ThreadInfo[] getThreadInfo(long[] ids); |
| |
| /** |
| * Returns a thread info for a thread of the specified <tt>id</tt>, |
| * with stack trace of a specified number of stack trace elements. |
| * The <tt>maxDepth</tt> parameter indicates the maximum number of |
| * {@link StackTraceElement} to be retrieved from the stack trace. |
| * If <tt>maxDepth == Integer.MAX_VALUE</tt>, the entire stack trace of |
| * the thread will be dumped. |
| * If <tt>maxDepth == 0</tt>, no stack trace of the thread |
| * will be dumped. |
| * This method does not obtain the locked monitors and locked |
| * synchronizers of the thread. |
| * <p> |
| * When the Java virtual machine has no stack trace information |
| * about a thread or <tt>maxDepth == 0</tt>, |
| * the stack trace in the |
| * <tt>ThreadInfo</tt> object will be an empty array of |
| * <tt>StackTraceElement</tt>. |
| * |
| * <p> |
| * If a thread of the given ID is not alive or does not exist, |
| * this method will return <tt>null</tt>. A thread is alive if |
| * it has been started and has not yet died. |
| * |
| * <p> |
| * <b>MBeanServer access</b>:<br> |
| * The mapped type of <tt>ThreadInfo</tt> is |
| * <tt>CompositeData</tt> with attributes as specified in the |
| * {@link ThreadInfo#from ThreadInfo.from} method. |
| * |
| * @param id the thread ID of the thread. Must be positive. |
| * @param maxDepth the maximum number of entries in the stack trace |
| * to be dumped. <tt>Integer.MAX_VALUE</tt> could be used to request |
| * the entire stack to be dumped. |
| * |
| * @return a {@link ThreadInfo} of the thread of the given ID |
| * with no locked monitor and synchronizer info. |
| * <tt>null</tt> if the thread of the given ID is not alive or |
| * it does not exist. |
| * |
| * @throws IllegalArgumentException if <tt>id <= 0</tt>. |
| * @throws IllegalArgumentException if <tt>maxDepth is negative</tt>. |
| * @throws java.lang.SecurityException if a security manager |
| * exists and the caller does not have |
| * ManagementPermission("monitor"). |
| * |
| */ |
| public ThreadInfo getThreadInfo(long id, int maxDepth); |
| |
| /** |
| * Returns the thread info for each thread |
| * whose ID is in the input array <tt>ids</tt>, |
| * with stack trace of a specified number of stack trace elements. |
| * The <tt>maxDepth</tt> parameter indicates the maximum number of |
| * {@link StackTraceElement} to be retrieved from the stack trace. |
| * If <tt>maxDepth == Integer.MAX_VALUE</tt>, the entire stack trace of |
| * the thread will be dumped. |
| * If <tt>maxDepth == 0</tt>, no stack trace of the thread |
| * will be dumped. |
| * This method does not obtain the locked monitors and locked |
| * synchronizers of the threads. |
| * <p> |
| * When the Java virtual machine has no stack trace information |
| * about a thread or <tt>maxDepth == 0</tt>, |
| * the stack trace in the |
| * <tt>ThreadInfo</tt> object will be an empty array of |
| * <tt>StackTraceElement</tt>. |
| * <p> |
| * This method returns an array of the <tt>ThreadInfo</tt> objects, |
| * each is the thread information about the thread with the same index |
| * as in the <tt>ids</tt> array. |
| * If a thread of the given ID is not alive or does not exist, |
| * <tt>null</tt> will be set in the corresponding element |
| * in the returned array. A thread is alive if |
| * it has been started and has not yet died. |
| * |
| * <p> |
| * <b>MBeanServer access</b>:<br> |
| * The mapped type of <tt>ThreadInfo</tt> is |
| * <tt>CompositeData</tt> with attributes as specified in the |
| * {@link ThreadInfo#from ThreadInfo.from} method. |
| * |
| * @param ids an array of thread IDs |
| * @param maxDepth the maximum number of entries in the stack trace |
| * to be dumped. <tt>Integer.MAX_VALUE</tt> could be used to request |
| * the entire stack to be dumped. |
| * |
| * @return an array of the {@link ThreadInfo} objects, each containing |
| * information about a thread whose ID is in the corresponding |
| * element of the input array of IDs with no locked monitor and |
| * synchronizer info. |
| * |
| * @throws IllegalArgumentException if <tt>maxDepth is negative</tt>. |
| * @throws IllegalArgumentException if any element in the input array |
| * <tt>ids</tt> is <tt><= 0</tt>. |
| * @throws java.lang.SecurityException if a security manager |
| * exists and the caller does not have |
| * ManagementPermission("monitor"). |
| * |
| */ |
| public ThreadInfo[] getThreadInfo(long[] ids, int maxDepth); |
| |
| /** |
| * Tests if the Java virtual machine supports thread contention monitoring. |
| * |
| * @return |
| * <tt>true</tt> |
| * if the Java virtual machine supports thread contention monitoring; |
| * <tt>false</tt> otherwise. |
| */ |
| public boolean isThreadContentionMonitoringSupported(); |
| |
| /** |
| * Tests if thread contention monitoring is enabled. |
| * |
| * @return <tt>true</tt> if thread contention monitoring is enabled; |
| * <tt>false</tt> otherwise. |
| * |
| * @throws java.lang.UnsupportedOperationException if the Java virtual |
| * machine does not support thread contention monitoring. |
| * |
| * @see #isThreadContentionMonitoringSupported |
| */ |
| public boolean isThreadContentionMonitoringEnabled(); |
| |
| /** |
| * Enables or disables thread contention monitoring. |
| * Thread contention monitoring is disabled by default. |
| * |
| * @param enable <tt>true</tt> to enable; |
| * <tt>false</tt> to disable. |
| * |
| * @throws java.lang.UnsupportedOperationException if the Java |
| * virtual machine does not support thread contention monitoring. |
| * |
| * @throws java.lang.SecurityException if a security manager |
| * exists and the caller does not have |
| * ManagementPermission("control"). |
| * |
| * @see #isThreadContentionMonitoringSupported |
| */ |
| public void setThreadContentionMonitoringEnabled(boolean enable); |
| |
| /** |
| * Returns the total CPU time for the current thread in nanoseconds. |
| * The returned value is of nanoseconds precision but |
| * not necessarily nanoseconds accuracy. |
| * If the implementation distinguishes between user mode time and system |
| * mode time, the returned CPU time is the amount of time that |
| * the current thread has executed in user mode or system mode. |
| * |
| * <p> |
| * This is a convenient method for local management use and is |
| * equivalent to calling: |
| * <blockquote><pre> |
| * {@link #getThreadCpuTime getThreadCpuTime}(Thread.currentThread().getId()); |
| * </pre></blockquote> |
| * |
| * @return the total CPU time for the current thread if CPU time |
| * measurement is enabled; <tt>-1</tt> otherwise. |
| * |
| * @throws java.lang.UnsupportedOperationException if the Java |
| * virtual machine does not support CPU time measurement for |
| * the current thread. |
| * |
| * @see #getCurrentThreadUserTime |
| * @see #isCurrentThreadCpuTimeSupported |
| * @see #isThreadCpuTimeEnabled |
| * @see #setThreadCpuTimeEnabled |
| */ |
| public long getCurrentThreadCpuTime(); |
| |
| /** |
| * Returns the CPU time that the current thread has executed |
| * in user mode in nanoseconds. |
| * The returned value is of nanoseconds precision but |
| * not necessarily nanoseconds accuracy. |
| * |
| * <p> |
| * This is a convenient method for local management use and is |
| * equivalent to calling: |
| * <blockquote><pre> |
| * {@link #getThreadUserTime getThreadUserTime}(Thread.currentThread().getId()); |
| * </pre></blockquote> |
| * |
| * @return the user-level CPU time for the current thread if CPU time |
| * measurement is enabled; <tt>-1</tt> otherwise. |
| * |
| * @throws java.lang.UnsupportedOperationException if the Java |
| * virtual machine does not support CPU time measurement for |
| * the current thread. |
| * |
| * @see #getCurrentThreadCpuTime |
| * @see #isCurrentThreadCpuTimeSupported |
| * @see #isThreadCpuTimeEnabled |
| * @see #setThreadCpuTimeEnabled |
| */ |
| public long getCurrentThreadUserTime(); |
| |
| /** |
| * Returns the total CPU time for a thread of the specified ID in nanoseconds. |
| * The returned value is of nanoseconds precision but |
| * not necessarily nanoseconds accuracy. |
| * If the implementation distinguishes between user mode time and system |
| * mode time, the returned CPU time is the amount of time that |
| * the thread has executed in user mode or system mode. |
| * |
| * <p> |
| * If the thread of the specified ID is not alive or does not exist, |
| * this method returns <tt>-1</tt>. If CPU time measurement |
| * is disabled, this method returns <tt>-1</tt>. |
| * A thread is alive if it has been started and has not yet died. |
| * <p> |
| * If CPU time measurement is enabled after the thread has started, |
| * the Java virtual machine implementation may choose any time up to |
| * and including the time that the capability is enabled as the point |
| * where CPU time measurement starts. |
| * |
| * @param id the thread ID of a thread |
| * @return the total CPU time for a thread of the specified ID |
| * if the thread of the specified ID exists, the thread is alive, |
| * and CPU time measurement is enabled; |
| * <tt>-1</tt> otherwise. |
| * |
| * @throws IllegalArgumentException if <tt>id <= 0 </tt>. |
| * @throws java.lang.UnsupportedOperationException if the Java |
| * virtual machine does not support CPU time measurement for |
| * other threads. |
| * |
| * @see #getThreadUserTime |
| * @see #isThreadCpuTimeSupported |
| * @see #isThreadCpuTimeEnabled |
| * @see #setThreadCpuTimeEnabled |
| */ |
| public long getThreadCpuTime(long id); |
| |
| /** |
| * Returns the CPU time that a thread of the specified ID |
| * has executed in user mode in nanoseconds. |
| * The returned value is of nanoseconds precision but |
| * not necessarily nanoseconds accuracy. |
| * |
| * <p> |
| * If the thread of the specified ID is not alive or does not exist, |
| * this method returns <tt>-1</tt>. If CPU time measurement |
| * is disabled, this method returns <tt>-1</tt>. |
| * A thread is alive if it has been started and has not yet died. |
| * <p> |
| * If CPU time measurement is enabled after the thread has started, |
| * the Java virtual machine implementation may choose any time up to |
| * and including the time that the capability is enabled as the point |
| * where CPU time measurement starts. |
| * |
| * @param id the thread ID of a thread |
| * @return the user-level CPU time for a thread of the specified ID |
| * if the thread of the specified ID exists, the thread is alive, |
| * and CPU time measurement is enabled; |
| * <tt>-1</tt> otherwise. |
| * |
| * @throws IllegalArgumentException if <tt>id <= 0 </tt>. |
| * @throws java.lang.UnsupportedOperationException if the Java |
| * virtual machine does not support CPU time measurement for |
| * other threads. |
| * |
| * @see #getThreadCpuTime |
| * @see #isThreadCpuTimeSupported |
| * @see #isThreadCpuTimeEnabled |
| * @see #setThreadCpuTimeEnabled |
| */ |
| public long getThreadUserTime(long id); |
| |
| /** |
| * Tests if the Java virtual machine implementation supports CPU time |
| * measurement for any thread. |
| * A Java virtual machine implementation that supports CPU time |
| * measurement for any thread will also support CPU time |
| * measurement for the current thread. |
| * |
| * @return |
| * <tt>true</tt> |
| * if the Java virtual machine supports CPU time |
| * measurement for any thread; |
| * <tt>false</tt> otherwise. |
| */ |
| public boolean isThreadCpuTimeSupported(); |
| |
| /** |
| * Tests if the Java virtual machine supports CPU time |
| * measurement for the current thread. |
| * This method returns <tt>true</tt> if {@link #isThreadCpuTimeSupported} |
| * returns <tt>true</tt>. |
| * |
| * @return |
| * <tt>true</tt> |
| * if the Java virtual machine supports CPU time |
| * measurement for current thread; |
| * <tt>false</tt> otherwise. |
| */ |
| public boolean isCurrentThreadCpuTimeSupported(); |
| |
| /** |
| * Tests if thread CPU time measurement is enabled. |
| * |
| * @return <tt>true</tt> if thread CPU time measurement is enabled; |
| * <tt>false</tt> otherwise. |
| * |
| * @throws java.lang.UnsupportedOperationException if the Java virtual |
| * machine does not support CPU time measurement for other threads |
| * nor for the current thread. |
| * |
| * @see #isThreadCpuTimeSupported |
| * @see #isCurrentThreadCpuTimeSupported |
| */ |
| public boolean isThreadCpuTimeEnabled(); |
| |
| /** |
| * Enables or disables thread CPU time measurement. The default |
| * is platform dependent. |
| * |
| * @param enable <tt>true</tt> to enable; |
| * <tt>false</tt> to disable. |
| * |
| * @throws java.lang.UnsupportedOperationException if the Java |
| * virtual machine does not support CPU time measurement for |
| * any threads nor for the current thread. |
| * |
| * @throws java.lang.SecurityException if a security manager |
| * exists and the caller does not have |
| * ManagementPermission("control"). |
| * |
| * @see #isThreadCpuTimeSupported |
| * @see #isCurrentThreadCpuTimeSupported |
| */ |
| public void setThreadCpuTimeEnabled(boolean enable); |
| |
| /** |
| * Finds cycles of threads that are in deadlock waiting to acquire |
| * object monitors. That is, threads that are blocked waiting to enter a |
| * synchronization block or waiting to reenter a synchronization block |
| * after an {@link Object#wait Object.wait} call, |
| * where each thread owns one monitor while |
| * trying to obtain another monitor already held by another thread |
| * in a cycle. |
| * <p> |
| * More formally, a thread is <em>monitor deadlocked</em> if it is |
| * part of a cycle in the relation "is waiting for an object monitor |
| * owned by". In the simplest case, thread A is blocked waiting |
| * for a monitor owned by thread B, and thread B is blocked waiting |
| * for a monitor owned by thread A. |
| * <p> |
| * This method is designed for troubleshooting use, but not for |
| * synchronization control. It might be an expensive operation. |
| * <p> |
| * This method finds deadlocks involving only object monitors. |
| * To find deadlocks involving both object monitors and |
| * <a href="LockInfo.html#OwnableSynchronizer">ownable synchronizers</a>, |
| * the {@link #findDeadlockedThreads findDeadlockedThreads} method |
| * should be used. |
| * |
| * @return an array of IDs of the threads that are monitor |
| * deadlocked, if any; <tt>null</tt> otherwise. |
| * |
| * @throws java.lang.SecurityException if a security manager |
| * exists and the caller does not have |
| * ManagementPermission("monitor"). |
| * |
| * @see #findDeadlockedThreads |
| */ |
| public long[] findMonitorDeadlockedThreads(); |
| |
| /** |
| * Resets the peak thread count to the current number of |
| * live threads. |
| * |
| * @throws java.lang.SecurityException if a security manager |
| * exists and the caller does not have |
| * ManagementPermission("control"). |
| * |
| * @see #getPeakThreadCount |
| * @see #getThreadCount |
| */ |
| public void resetPeakThreadCount(); |
| |
| /** |
| * Finds cycles of threads that are in deadlock waiting to acquire |
| * object monitors or |
| * <a href="LockInfo.html#OwnableSynchronizer">ownable synchronizers</a>. |
| * |
| * Threads are <em>deadlocked</em> in a cycle waiting for a lock of |
| * these two types if each thread owns one lock while |
| * trying to acquire another lock already held |
| * by another thread in the cycle. |
| * <p> |
| * This method is designed for troubleshooting use, but not for |
| * synchronization control. It might be an expensive operation. |
| * |
| * @return an array of IDs of the threads that are |
| * deadlocked waiting for object monitors or ownable synchronizers, if any; |
| * <tt>null</tt> otherwise. |
| * |
| * @throws java.lang.SecurityException if a security manager |
| * exists and the caller does not have |
| * ManagementPermission("monitor"). |
| * @throws java.lang.UnsupportedOperationException if the Java virtual |
| * machine does not support monitoriing of ownable synchronizer usage. |
| * |
| * @see #isSynchronizerUsageSupported |
| * @see #findMonitorDeadlockedThreads |
| * @since 1.6 |
| */ |
| public long[] findDeadlockedThreads(); |
| |
| /** |
| * Tests if the Java virtual machine supports monitoring of |
| * object monitor usage. |
| * |
| * @return |
| * <tt>true</tt> |
| * if the Java virtual machine supports monitoring of |
| * object monitor usage; |
| * <tt>false</tt> otherwise. |
| * |
| * @see #dumpAllThreads |
| * @since 1.6 |
| */ |
| public boolean isObjectMonitorUsageSupported(); |
| |
| /** |
| * Tests if the Java virtual machine supports monitoring of |
| * <a href="LockInfo.html#OwnableSynchronizer"> |
| * ownable synchronizer</a> usage. |
| * |
| * @return |
| * <tt>true</tt> |
| * if the Java virtual machine supports monitoring of ownable |
| * synchronizer usage; |
| * <tt>false</tt> otherwise. |
| * |
| * @see #dumpAllThreads |
| * @since 1.6 |
| */ |
| public boolean isSynchronizerUsageSupported(); |
| |
| /** |
| * Returns the thread info for each thread |
| * whose ID is in the input array <tt>ids</tt>, with stack trace |
| * and synchronization information. |
| * |
| * <p> |
| * This method obtains a snapshot of the thread information |
| * for each thread including: |
| * <ul> |
| * <li>the entire stack trace,</li> |
| * <li>the object monitors currently locked by the thread |
| * if <tt>lockedMonitors</tt> is <tt>true</tt>, and</li> |
| * <li>the <a href="LockInfo.html#OwnableSynchronizer"> |
| * ownable synchronizers</a> currently locked by the thread |
| * if <tt>lockedSynchronizers</tt> is <tt>true</tt>.</li> |
| * </ul> |
| * <p> |
| * This method returns an array of the <tt>ThreadInfo</tt> objects, |
| * each is the thread information about the thread with the same index |
| * as in the <tt>ids</tt> array. |
| * If a thread of the given ID is not alive or does not exist, |
| * <tt>null</tt> will be set in the corresponding element |
| * in the returned array. A thread is alive if |
| * it has been started and has not yet died. |
| * <p> |
| * If a thread does not lock any object monitor or <tt>lockedMonitors</tt> |
| * is <tt>false</tt>, the returned <tt>ThreadInfo</tt> object will have an |
| * empty <tt>MonitorInfo</tt> array. Similarly, if a thread does not |
| * lock any synchronizer or <tt>lockedSynchronizers</tt> is <tt>false</tt>, |
| * the returned <tt>ThreadInfo</tt> object |
| * will have an empty <tt>LockInfo</tt> array. |
| * |
| * <p> |
| * When both <tt>lockedMonitors</tt> and <tt>lockedSynchronizers</tt> |
| * parameters are <tt>false</tt>, it is equivalent to calling: |
| * <blockquote><pre> |
| * {@link #getThreadInfo(long[], int) getThreadInfo(ids, Integer.MAX_VALUE)} |
| * </pre></blockquote> |
| * |
| * <p> |
| * This method is designed for troubleshooting use, but not for |
| * synchronization control. It might be an expensive operation. |
| * |
| * <p> |
| * <b>MBeanServer access</b>:<br> |
| * The mapped type of <tt>ThreadInfo</tt> is |
| * <tt>CompositeData</tt> with attributes as specified in the |
| * {@link ThreadInfo#from ThreadInfo.from} method. |
| * |
| * @param ids an array of thread IDs. |
| * @param lockedMonitors if <tt>true</tt>, retrieves all locked monitors. |
| * @param lockedSynchronizers if <tt>true</tt>, retrieves all locked |
| * ownable synchronizers. |
| * |
| * @return an array of the {@link ThreadInfo} objects, each containing |
| * information about a thread whose ID is in the corresponding |
| * element of the input array of IDs. |
| * |
| * @throws java.lang.SecurityException if a security manager |
| * exists and the caller does not have |
| * ManagementPermission("monitor"). |
| * @throws java.lang.UnsupportedOperationException |
| * <ul> |
| * <li>if <tt>lockedMonitors</tt> is <tt>true</tt> but |
| * the Java virtual machine does not support monitoring |
| * of {@linkplain #isObjectMonitorUsageSupported |
| * object monitor usage}; or</li> |
| * <li>if <tt>lockedSynchronizers</tt> is <tt>true</tt> but |
| * the Java virtual machine does not support monitoring |
| * of {@linkplain #isSynchronizerUsageSupported |
| * ownable synchronizer usage}.</li> |
| * </ul> |
| * |
| * @see #isObjectMonitorUsageSupported |
| * @see #isSynchronizerUsageSupported |
| * |
| * @since 1.6 |
| */ |
| public ThreadInfo[] getThreadInfo(long[] ids, boolean lockedMonitors, boolean lockedSynchronizers); |
| |
| /** |
| * Returns the thread info for all live threads with stack trace |
| * and synchronization information. |
| * Some threads included in the returned array |
| * may have been terminated when this method returns. |
| * |
| * <p> |
| * This method returns an array of {@link ThreadInfo} objects |
| * as specified in the {@link #getThreadInfo(long[], boolean, boolean)} |
| * method. |
| * |
| * @param lockedMonitors if <tt>true</tt>, dump all locked monitors. |
| * @param lockedSynchronizers if <tt>true</tt>, dump all locked |
| * ownable synchronizers. |
| * |
| * @return an array of {@link ThreadInfo} for all live threads. |
| * |
| * @throws java.lang.SecurityException if a security manager |
| * exists and the caller does not have |
| * ManagementPermission("monitor"). |
| * @throws java.lang.UnsupportedOperationException |
| * <ul> |
| * <li>if <tt>lockedMonitors</tt> is <tt>true</tt> but |
| * the Java virtual machine does not support monitoring |
| * of {@linkplain #isObjectMonitorUsageSupported |
| * object monitor usage}; or</li> |
| * <li>if <tt>lockedSynchronizers</tt> is <tt>true</tt> but |
| * the Java virtual machine does not support monitoring |
| * of {@linkplain #isSynchronizerUsageSupported |
| * ownable synchronizer usage}.</li> |
| * </ul> |
| * |
| * @see #isObjectMonitorUsageSupported |
| * @see #isSynchronizerUsageSupported |
| * |
| * @since 1.6 |
| */ |
| public ThreadInfo[] dumpAllThreads(boolean lockedMonitors, boolean lockedSynchronizers); |
| } |
