Package org.jline.builtins

Class TTop

java.lang.Object

org.jline.builtins.TTop

public class TTop
extends Object

A terminal-based thread monitoring tool similar to the 'top' Unix command.

This class provides a real-time view of thread activity in the JVM, displaying information such as thread states, CPU usage, blocking, and waiting statistics. Features include:

• Sortable thread list with multiple metrics
• Customizable display columns
• Interactive navigation and filtering
• System resource statistics
• Thread state visualization

The implementation provides a terminal UI for monitoring thread activity, which can be useful for diagnosing performance issues and thread contention.

TODO: option modification at runtime (such as implemented in less) is not currently supported TODO: one possible addition would be to detect deadlock threads and display them in a specific way

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	TTop.Align
private static class	TTop.Column
static enum	TTop.Operation

Field Summary

Fields

Modifier and Type	Field	Description
private final BindingReader	bindingReader
private Map<Long,Map<String,Long>>	changes
private final Map<String,TTop.Column>	columns
private Comparator<Map<String,Comparable<?>>>	comparator
long	delay
private final Display	display
private final KeyMap<TTop.Operation>	keys
int	nthreads
private Map<Long,Map<String,Object>>	previous
private final Size	size
List<String>	sort
static final String	STAT_BLOCKED_COUNT
static final String	STAT_BLOCKED_TIME
static final String	STAT_CPU_TIME
static final String	STAT_CPU_TIME_PERC
static final String	STAT_LOCK_NAME
static final String	STAT_LOCK_OWNER_ID
static final String	STAT_LOCK_OWNER_NAME
static final String	STAT_NAME
static final String	STAT_STATE
static final String	STAT_TID
static final String	STAT_UPTIME
static final String	STAT_USER_TIME
static final String	STAT_USER_TIME_PERC
static final String	STAT_WAITED_COUNT
static final String	STAT_WAITED_TIME
List<String>	stats
private final Terminal	terminal
private Map<String,Integer>	widths

Constructor Summary

Constructors

Constructor	Description
TTop(Terminal terminal)

Method Summary

Modifier and Type	Method	Description
private void	align(AttributedStringBuilder sb, String val, int width, TTop.Align align)
private void	bindKeys(KeyMap<TTop.Operation> map)
private Comparator<Map<String,Comparable<?>>>	buildComparator(List<String> sort)
private void	checkInterrupted()	This is for long running commands to be interrupted by ctrl-c
private void	display()
KeyMap<TTop.Operation>	getKeys()
private void	handle(Terminal.Signal signal)
private static String	humanReadableByteCount(long bytes, boolean si)
private List<Map<String,Comparable<?>>>	infos()
private static String	memory(long cur, long max)
private static String	millis(long millis)
private static String	nanos(long nanos)
private static Function<Object,String>	padcut(int nb)
private static String	padcut(String str, int nb)
private void	register(String name, TTop.Align align, String header, Function<Object,String> format)
void	run()
static void	ttop(Terminal terminal, PrintStream out, PrintStream err, String[] argv)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

STAT_UPTIME

public static final String STAT_UPTIME

See Also:

• Constant Field Values

STAT_TID

public static final String STAT_TID

See Also:

• Constant Field Values

STAT_NAME

public static final String STAT_NAME

See Also:

• Constant Field Values

STAT_STATE

public static final String STAT_STATE

See Also:

• Constant Field Values

STAT_BLOCKED_TIME

public static final String STAT_BLOCKED_TIME

See Also:

• Constant Field Values

STAT_BLOCKED_COUNT

public static final String STAT_BLOCKED_COUNT

See Also:

• Constant Field Values

STAT_WAITED_TIME

public static final String STAT_WAITED_TIME

See Also:

• Constant Field Values

STAT_WAITED_COUNT

public static final String STAT_WAITED_COUNT

See Also:

• Constant Field Values

STAT_LOCK_NAME

public static final String STAT_LOCK_NAME

See Also:

• Constant Field Values

STAT_LOCK_OWNER_ID

public static final String STAT_LOCK_OWNER_ID

See Also:

• Constant Field Values

STAT_LOCK_OWNER_NAME

public static final String STAT_LOCK_OWNER_NAME

See Also:

• Constant Field Values

STAT_USER_TIME

public static final String STAT_USER_TIME

See Also:

• Constant Field Values

STAT_USER_TIME_PERC

public static final String STAT_USER_TIME_PERC

See Also:

• Constant Field Values

STAT_CPU_TIME

public static final String STAT_CPU_TIME

See Also:

• Constant Field Values

STAT_CPU_TIME_PERC

public static final String STAT_CPU_TIME_PERC

See Also:

• Constant Field Values

sort

public List<String> sort

delay

public long delay

stats

public List<String> stats

nthreads

public int nthreads

columns

private final Map<String,TTop.Column> columns

terminal

private final Terminal terminal

display

private final Display display

bindingReader

private final BindingReader bindingReader

keys

private final KeyMap<TTop.Operation> keys

size

private final Size size

comparator

private Comparator<Map<String,Comparable<?>>> comparator

previous

private Map<Long,Map<String,Object>> previous

changes

private Map<Long,Map<String,Long>> changes

widths

private Map<String,Integer> widths

Constructor Details

TTop

public TTop(Terminal terminal)

Method Details

ttop

public static void ttop(Terminal terminal,
 PrintStream out,
 PrintStream err,
 String[] argv)
                 throws Exception

Throws:

Exception

getKeys

public KeyMap<TTop.Operation> getKeys()

run

public void run()
         throws IOException,
InterruptedException

Throws:

IOException

InterruptedException

handle

private void handle(Terminal.Signal signal)

infos

private List<Map<String,Comparable<?>>> infos()

align

private void align(AttributedStringBuilder sb,
 String val,
 int width,
 TTop.Align align)

display

private void display()
              throws IOException

Throws:

IOException

buildComparator

private Comparator<Map<String,Comparable<?>>> buildComparator(List<String> sort)

register

private void register(String name,
 TTop.Align align,
 String header,
 Function<Object,String> format)

nanos

private static String nanos(long nanos)

millis

private static String millis(long millis)

padcut

private static Function<Object,String> padcut(int nb)

padcut

private static String padcut(String str,
 int nb)

memory

private static String memory(long cur,
 long max)

humanReadableByteCount

private static String humanReadableByteCount(long bytes,
 boolean si)

checkInterrupted

private void checkInterrupted()
                       throws InterruptedException

This is for long running commands to be interrupted by ctrl-c

Throws:

InterruptedException

bindKeys

private void bindKeys(KeyMap<TTop.Operation> map)