Class ThreadInfo

public static ThreadInfo from(CompositeData data)

Returns a ThreadInfo instance using the values given in the supplied CompositeData object. The composite data instance should contain the following attributes with the specified types:

	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
lockName	java.lang.String
lockOwnerId	java.lang.Long
lockOwnerName	java.lang.String
stackTrace	javax.management.openmbean.CompositeData[]

The stack trace is further described as:

	Name	Type
className	java.lang.String
methodName	java.lang.String
fileName	java.lang.String
lineNumber	java.lang.Integer
nativeMethod	java.lang.Boolean

Parameters:

data - the composite data structure to take values from.

Returns:

a new instance containing the values from the composite data structure, or null if the data structure was also null.

Throws:

IllegalArgumentException - if the composite data structure does not match the structure outlined above.

public long getBlockedCount()

Returns the number of times this thread has been in the Thread.State state. A thread enters this state when it is waiting to obtain an object's monitor. This may occur either on entering a synchronized method for the first time, or on re-entering it following a call to Object.wait().

Returns:

the number of times this thread has been blocked.

public long getBlockedTime()

Returns the accumulated number of milliseconds this thread has been in the Thread.State state since thread contention monitoring was last enabled. A thread enters this state when it is waiting to obtain an object's monitor. This may occur either on entering a synchronized method for the first time, or on re-entering it following a call to Object.wait().

Use of this method requires virtual machine support for thread contention monitoring and for this support to be enabled.

Returns:

the accumulated time (in milliseconds) that this thread has spent in the blocked state, since thread contention monitoring was enabled, or -1 if thread contention monitoring is disabled.

Throws:

UnsupportedOperationException - if the virtual machine does not support contention monitoring.

See Also:

ThreadMXBean.isThreadContentionMonitoringEnabled(), ThreadMXBean.isThreadContentionMonitoringSupported()

public LockInfo getLockInfo()

Returns a LockInfo object representing the lock on which this thread is blocked. If the thread is not blocked, this method returns null.

The thread may be blocked due to one of three reasons:

1. The thread is in the BLOCKED state waiting to acquire an object monitor in order to enter a synchronized method or block.
2. The thread is in the WAITING or TIMED_WAITING state due to a call to Object.wait().
3. The thread is in the WAITING or TIMED_WAITING state due to a call to java.util.concurrent.locks.LockSupport.park(). The lock is the return value of java.util.concurrent.locks.LockSupport.getBlocker().

Returns:

a LockInfo object representing the lock on which the thread is blocked, or null if the thread isn't blocked.

Since:

1.6

See Also:

getLockName()

public String getLockName()

Returns a String representation of the lock on which this thread is blocked. If the thread is not blocked, this method returns null.

The returned String is constructed using the class name and identity hashcode (usually the memory address of the object) of the lock. The two are separated by the '@' character, and the identity hashcode is represented in hexadecimal. Thus, for a lock, l, the returned value is the result of concatenating l.getClass().getName(), "@" and Integer.toHexString(System.identityHashCode(l)). The value is only unique to the extent that the identity hash code is also unique. The value is the same as would be returned by getLockInfo().toString()

Returns:

a string representing the lock on which this thread is blocked, or null if the thread is not blocked.

public long getLockOwnerId()

Returns the identifier of the thread which owns the monitor lock this thread is waiting for. -1 is returned if either this thread is not blocked, or the lock is not held by any other thread.

Returns:

the thread identifier of thread holding the lock this thread is waiting for, or -1 if the thread is not blocked or the lock is not held by another thread.

public String getLockOwnerName()

Returns the name of the thread which owns the monitor lock this thread is waiting for. null is returned if either this thread is not blocked, or the lock is not held by any other thread.

Returns:

the thread identifier of thread holding the lock this thread is waiting for, or null if the thread is not blocked or the lock is not held by another thread.

public MonitorInfo[] getLockedMonitors()

Returns an array of MonitorInfo objects representing information on the locks on object monitors held by the thread. If no locks are held, or such information was not requested on creating this ThreadInfo object, a zero-length array will be returned.

Returns:

information on object monitors locked by this thread.

public LockInfo[] getLockedSynchronizers()

Returns an array of LockInfo objects representing information on the locks on ownable synchronizers held by the thread. If no locks are held, or such information was not requested on creating this ThreadInfo object, a zero-length array will be returned.

Returns:

information on ownable synchronizers locked by this thread.

public StackTraceElement[] getStackTrace()

Returns the stack trace of this thread to the depth specified on creation of this ThreadInfo object. If the depth is zero, an empty array will be returned. For non-zero arrays, the elements start with the most recent trace at position zero. The bottom of the stack represents the oldest method invocation which meets the depth requirements.

Some virtual machines may not be able to return stack trace information for a thread. In these cases, an empty array will also be returned.

Returns:

an array of StackTraceElements representing the trace of this thread.

public long getThreadId()

Returns the identifier of the thread associated with this instance of ThreadInfo.

Returns:

the thread's identifier.

public String getThreadName()

Returns the name of the thread associated with this instance of ThreadInfo.

Returns:

the thread's name.

public Thread.State getThreadState()

Returns the state of the thread associated with this instance of ThreadInfo.

Returns:

the thread's state.

public long getWaitedCount()

Returns the number of times this thread has been in the Thread.State or Thread.State state. A thread enters one of these states when it is waiting due to a call to java.lang.Object.wait(), java.lang.Object.join() or java.lang.concurrent.locks.LockSupport.park(), either with an infinite or timed delay, respectively.

Returns:

the number of times this thread has been waiting.

public long getWaitedTime()

Returns the accumulated number of milliseconds this thread has been in the Thread.State or Thread.State state, since thread contention monitoring was last enabled. A thread enters one of these states when it is waiting due to a call to java.lang.Object.wait(), java.lang.Object.join() or java.lang.concurrent.locks.LockSupport.park(), either with an infinite or timed delay, respectively.

Use of this method requires virtual machine support for thread contention monitoring and for this support to be enabled.

Returns:

the accumulated time (in milliseconds) that this thread has spent in one of the waiting states, since thread contention monitoring was enabled, or -1 if thread contention monitoring is disabled.

Throws:

UnsupportedOperationException - if the virtual machine does not support contention monitoring.

See Also:

ThreadMXBean.isThreadContentionMonitoringEnabled(), ThreadMXBean.isThreadContentionMonitoringSupported()

public boolean isInNative()

Returns true if the thread is in a native method. This excludes native code which forms part of the virtual machine itself, or which results from Just-In-Time compilation.

Returns:

true if the thread is in a native method, false otherwise.

public boolean isSuspended()

Returns true if the thread has been suspended using Thread.suspend().

Returns:

true if the thread is suspended, false otherwise.

public String toString()

Returns a String representation of this ThreadInfo object. This takes the form java.lang.management.ThreadInfo[id=tid, name=n, state=s, blockedCount=bc, waitedCount=wc, isInNative=iin, isSuspended=is], where tid is the thread identifier, n is the thread name, s is the thread state, bc is the blocked state count, wc is the waiting state count and iin and is are boolean flags to indicate the thread is in native code or suspended respectively. If the thread is blocked, lock=l, lockOwner=lo is also included, where l is the lock waited for, and lo is the thread which owns the lock (or null if there is no owner).

Overrides:

toString in interface Object

Returns:

the string specified above.