- /*
- * @(#)ThreadMXBean.java 1.14 04/04/29
- *
- * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
- * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
- */
-
- package java.lang.management;
-
- /**
- * 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>
- *
- * <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.
- * 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.
- *
- * @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
- * @version 1.14, 04/29/04
- * @since 1.5
- */
- public interface ThreadMXBean {
- /**
- * 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 in the returned <tt>ThreadInfo</tt> object will
- * be an empty array of <tt>StackTraceElement</tt>.
- *
- * 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
- * {@link ThreadInfo#from ThreadInfo}.
- *
- * @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;
- * <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 in each <tt>ThreadInfo</tt> object will
- * be an empty array of <tt>StackTraceElement</tt>.
- *
- * 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
- * {@link ThreadInfo#from ThreadInfo}.
- *
- * @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.
- *
- * @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>.
- * The <tt>maxDepth</tt> parameter indicates the maximum number of
- * <tt>StackTraceElement</tt> 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.
- * <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
- * {@link ThreadInfo#from ThreadInfo}.
- *
- * @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.
- * <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>.
- * The <tt>maxDepth</tt> parameter indicates the maximum number of
- * <tt>StackTraceElement</tt> 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.
- * <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
- * {@link ThreadInfo#from ThreadInfo}.
- *
- * @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.
- *
- * @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 precison 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 precison 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.
- *
- * @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").
- */
- 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();
- }
-