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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* 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.
*
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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 MBeanServer} method.
*
* <p>The {@code ObjectName} for uniquely identifying the MXBean for
* the thread system within an MBeanServer is:
* <blockquote>
* {@link ManagementFactory#THREAD_MXBEAN_NAME
* java.lang:type=Threading}
* </blockquote>
*
* It can be obtained by calling the
* {@link PlatformManagedObject#getObjectName} method.
*
* <h3>Thread ID</h3>
* 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.
*
* <h3>Thread CPU time</h3>
* 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.
*
* <h3>Thread Contention Monitoring</h3>
* 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">{@code ThreadInfo}</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.
*
* <h3>Synchronization Information and Deadlock Detection</h3>
* 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 {@code ThreadMXBean} 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 {@code long}, 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
* {@code id} with no stack trace.
* This method is equivalent to calling:
* <blockquote>
* {@link #getThreadInfo(long, int) getThreadInfo(id, 0);}
* </blockquote>
*
* <p>
* This method returns a {@code ThreadInfo} object representing
* the thread information for the thread of the specified ID.
* The stack trace, locked monitors, and locked synchronizers
* in the returned {@code ThreadInfo} object will
* be empty.
*
* If a thread of the given ID is not alive or does not exist,
* this method will return {@code null}. A thread is alive if
* it has been started and has not yet died.
*
* <p>
* <b>MBeanServer access</b>:<br>
* The mapped type of {@code ThreadInfo} is
* {@code CompositeData} 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;
* {@code null} if the thread of the given ID is not alive or
* it does not exist.
*
* @throws IllegalArgumentException if {@code id <= 0}.
* @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 {@code ids} 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 {@code ThreadInfo} objects.
* The stack trace, locked monitors, and locked synchronizers
* in each {@code ThreadInfo} 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 {@code null}. A thread is alive if
* it has been started and has not yet died.
*
* <p>
* <b>MBeanServer access</b>:<br>
* The mapped type of {@code ThreadInfo} is
* {@code CompositeData} 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
* {@code ids} is {@code <= 0}.
* @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 {@code id},
* with stack trace of a specified number of stack trace elements.
* The {@code maxDepth} parameter indicates the maximum number of
* {@link StackTraceElement} to be retrieved from the stack trace.
* If {@code maxDepth == Integer.MAX_VALUE}, the entire stack trace of
* the thread will be dumped.
* If {@code maxDepth == 0}, 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 {@code maxDepth == 0},
* the stack trace in the
* {@code ThreadInfo} object will be an empty array of
* {@code StackTraceElement}.
*
* <p>
* If a thread of the given ID is not alive or does not exist,
* this method will return {@code null}. A thread is alive if
* it has been started and has not yet died.
*
* <p>
* <b>MBeanServer access</b>:<br>
* The mapped type of {@code ThreadInfo} is
* {@code CompositeData} 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. {@code Integer.MAX_VALUE} 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.
* {@code null} if the thread of the given ID is not alive or
* it does not exist.
*
* @throws IllegalArgumentException if {@code id <= 0}.
* @throws IllegalArgumentException if {@code maxDepth is negative}.
* @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 {@code ids},
* with stack trace of a specified number of stack trace elements.
* The {@code maxDepth} parameter indicates the maximum number of
* {@link StackTraceElement} to be retrieved from the stack trace.
* If {@code maxDepth == Integer.MAX_VALUE}, the entire stack trace of
* the thread will be dumped.
* If {@code maxDepth == 0}, 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 {@code maxDepth == 0},
* the stack trace in the
* {@code ThreadInfo} object will be an empty array of
* {@code StackTraceElement}.
* <p>
* This method returns an array of the {@code ThreadInfo} objects,
* each is the thread information about the thread with the same index
* as in the {@code ids} array.
* If a thread of the given ID is not alive or does not exist,
* {@code null} 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 {@code ThreadInfo} is
* {@code CompositeData} 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. {@code Integer.MAX_VALUE} 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 {@code maxDepth is negative}.
* @throws IllegalArgumentException if any element in the input array
* {@code ids} is {@code <= 0}.
* @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
* {@code true}
* if the Java virtual machine supports thread contention monitoring;
* {@code false} otherwise.
*/
public boolean isThreadContentionMonitoringSupported();
/**
* Tests if thread contention monitoring is enabled.
*
* @return {@code true} if thread contention monitoring is enabled;
* {@code false} 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 {@code true} to enable;
* {@code false} 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; {@code -1} 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; {@code -1} 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 {@code -1}. If CPU time measurement
* is disabled, this method returns {@code -1}.
* 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;
* {@code -1} otherwise.
*
* @throws IllegalArgumentException if {@code id <= 0}.
* @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 {@code -1}. If CPU time measurement
* is disabled, this method returns {@code -1}.
* 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;
* {@code -1} otherwise.
*
* @throws IllegalArgumentException if {@code id <= 0}.
* @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
* {@code true}
* if the Java virtual machine supports CPU time
* measurement for any thread;
* {@code false} otherwise.
*/
public boolean isThreadCpuTimeSupported();
/**
* Tests if the Java virtual machine supports CPU time
* measurement for the current thread.
* This method returns {@code true} if {@link #isThreadCpuTimeSupported}
* returns {@code true}.
*
* @return
* {@code true}
* if the Java virtual machine supports CPU time
* measurement for current thread;
* {@code false} otherwise.
*/
public boolean isCurrentThreadCpuTimeSupported();
/**
* Tests if thread CPU time measurement is enabled.
*
* @return {@code true} if thread CPU time measurement is enabled;
* {@code false} 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 {@code true} to enable;
* {@code false} 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; {@code null} 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;
* {@code null} 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 monitoring 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
* {@code true}
* if the Java virtual machine supports monitoring of
* object monitor usage;
* {@code false} 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
* {@code true}
* if the Java virtual machine supports monitoring of ownable
* synchronizer usage;
* {@code false} otherwise.
*
* @see #dumpAllThreads
* @since 1.6
*/
public boolean isSynchronizerUsageSupported();
/**
* Returns the thread info for each thread
* whose ID is in the input array {@code ids},
* with stack trace and synchronization information.
* This is equivalent to calling:
* <blockquote>
* {@link #getThreadInfo(long[], boolean, boolean, int)
* getThreadInfo(ids, lockedMonitors, lockedSynchronizers, Integer.MAX_VALUE)}
* </blockquote>
*
* @param ids an array of thread IDs.
* @param lockedMonitors if {@code true}, retrieves all locked monitors.
* @param lockedSynchronizers if {@code true}, 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 {@code lockedMonitors} is {@code true} but
* the Java virtual machine does not support monitoring
* of {@linkplain #isObjectMonitorUsageSupported
* object monitor usage}; or</li>
* <li>if {@code lockedSynchronizers} is {@code true} 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 each thread whose ID
* is in the input array {@code ids},
* with stack trace of the specified maximum number of elements
* and synchronization information.
* If {@code maxDepth == 0}, no stack trace of the thread
* will be dumped.
*
* <p>
* This method obtains a snapshot of the thread information
* for each thread including:
* <ul>
* <li>stack trace of the specified maximum number of elements,</li>
* <li>the object monitors currently locked by the thread
* if {@code lockedMonitors} is {@code true}, and</li>
* <li>the <a href="LockInfo.html#OwnableSynchronizer">
* ownable synchronizers</a> currently locked by the thread
* if {@code lockedSynchronizers} is {@code true}.</li>
* </ul>
* <p>
* This method returns an array of the {@code ThreadInfo} objects,
* each is the thread information about the thread with the same index
* as in the {@code ids} array.
* If a thread of the given ID is not alive or does not exist,
* {@code null} 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 {@code lockedMonitors}
* is {@code false}, the returned {@code ThreadInfo} object will have an
* empty {@code MonitorInfo} array. Similarly, if a thread does not
* lock any synchronizer or {@code lockedSynchronizers} is {@code false},
* the returned {@code ThreadInfo} object
* will have an empty {@code LockInfo} array.
*
* <p>
* When both {@code lockedMonitors} and {@code lockedSynchronizers}
* parameters are {@code false}, it is equivalent to calling:
* <blockquote><pre>
* {@link #getThreadInfo(long[], int) getThreadInfo(ids, maxDepth)}
* </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 {@code ThreadInfo} is
* {@code CompositeData} with attributes as specified in the
* {@link ThreadInfo#from ThreadInfo.from} method.
*
* @implSpec The default implementation throws
* {@code UnsupportedOperationException}.
*
* @param ids an array of thread IDs.
* @param lockedMonitors if {@code true}, retrieves all locked monitors.
* @param lockedSynchronizers if {@code true}, retrieves all locked
* ownable synchronizers.
* @param maxDepth indicates the maximum number of
* {@link StackTraceElement} to be retrieved from the stack trace.
*
* @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 IllegalArgumentException if {@code maxDepth} is negative.
* @throws java.lang.SecurityException if a security manager
* exists and the caller does not have
* ManagementPermission("monitor").
* @throws java.lang.UnsupportedOperationException
* <ul>
* <li>if {@code lockedMonitors} is {@code true} but
* the Java virtual machine does not support monitoring
* of {@linkplain #isObjectMonitorUsageSupported
* object monitor usage}; or</li>
* <li>if {@code lockedSynchronizers} is {@code true} but
* the Java virtual machine does not support monitoring
* of {@linkplain #isSynchronizerUsageSupported
* ownable synchronizer usage}.</li>
* </ul>
*
* @see #isObjectMonitorUsageSupported
* @see #isSynchronizerUsageSupported
*
* @since 10
*/
public default ThreadInfo[] getThreadInfo(long[] ids, boolean lockedMonitors,
boolean lockedSynchronizers, int maxDepth) {
throw new UnsupportedOperationException();
}
/**
* Returns the thread info for all live threads with stack trace
* and synchronization information.
* This is equivalent to calling:
* <blockquote>
* {@link #dumpAllThreads(boolean, boolean, int)
* dumpAllThreads(lockedMonitors, lockedSynchronizers, Integer.MAX_VALUE)}
* </blockquote>
*
* @param lockedMonitors if {@code true}, dump all locked monitors.
* @param lockedSynchronizers if {@code true}, 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 {@code lockedMonitors} is {@code true} but
* the Java virtual machine does not support monitoring
* of {@linkplain #isObjectMonitorUsageSupported
* object monitor usage}; or</li>
* <li>if {@code lockedSynchronizers} is {@code true} 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);
/**
* Returns the thread info for all live threads
* with stack trace of the specified maximum number of elements
* and synchronization information.
* if {@code maxDepth == 0}, no stack trace of the thread
* will be dumped.
* 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, int)}
* method.
*
* @implSpec The default implementation throws
* {@code UnsupportedOperationException}.
*
* @param lockedMonitors if {@code true}, dump all locked monitors.
* @param lockedSynchronizers if {@code true}, dump all locked
* ownable synchronizers.
* @param maxDepth indicates the maximum number of
* {@link StackTraceElement} to be retrieved from the stack trace.
*
* @return an array of {@link ThreadInfo} for all live threads.
*
* @throws IllegalArgumentException if {@code maxDepth} is negative.
* @throws java.lang.SecurityException if a security manager
* exists and the caller does not have
* ManagementPermission("monitor").
* @throws java.lang.UnsupportedOperationException
* <ul>
* <li>if {@code lockedMonitors} is {@code true} but
* the Java virtual machine does not support monitoring
* of {@linkplain #isObjectMonitorUsageSupported
* object monitor usage}; or</li>
* <li>if {@code lockedSynchronizers} is {@code true} but
* the Java virtual machine does not support monitoring
* of {@linkplain #isSynchronizerUsageSupported
* ownable synchronizer usage}.</li>
* </ul>
*
* @see #isObjectMonitorUsageSupported
* @see #isSynchronizerUsageSupported
*
* @since 10
*/
public default ThreadInfo[] dumpAllThreads(boolean lockedMonitors,
boolean lockedSynchronizers, int maxDepth) {
throw new UnsupportedOperationException();
}
}