javatools.administrative
Class Tracer

java.lang.Object
  javatools.administrative.Tracer

public class Tracer
extends java.lang.Object

This class is part of the Java Tools (see http://mpii.de/yago-naga/javatools). It is licensed under the Creative Commons Attribution License (see http://creativecommons.org/licenses/by/3.0) by the YAGO-NAGA team (see http://mpii.de/yago-naga). This class allows to trace where a program hangs. Use as follows:

  Before calling a method in your program, call Tracer.signal():
      Tracer.signal("Calling blah");
  In your main method, state
      Tracer.start(number of milliseconds);

  Whenever the tracer does not receive a signal for the given number of milliseconds,
  it writes a warning, such as e.g.
     Calling blah hangs
  When it receives the next signal, it will say
     Hang resolved

Use the tracer for debugging purposes only.

Constructor Summary

Tracer()

Method Summary

static void	main(java.lang.String[] args) Calls test1 and test2 in a loop.
static boolean	signal(java.lang.Object... s) Send a signal to the tracer.
static boolean	start(long millisDelay) Start the tracer, accept millisDelay milliseconds between two signals before issuing a warning.
static void	stop() Stop the tracer
static void	test1() Sleeps for 2 seconds.
static void	test2() Sleeps for 5 seconds.

Methods inherited from class java.lang.Object

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

Constructor Detail

Tracer

public Tracer()

Method Detail

start

public static boolean start(long millisDelay)

Start the tracer, accept millisDelay milliseconds between two signals before issuing a warning. Returns TRUE so that it can be used in an assert statement

stop

public static void stop()

Stop the tracer

signal

public static boolean signal(java.lang.Object... s)

Send a signal to the tracer. Always returns TRUE so that it can be used in assert

test1

public static void test1()

Sleeps for 2 seconds. Tracer will not say anything

test2

public static void test2()

Sleeps for 5 seconds. Tracer will write a warning

main

public static void main(java.lang.String[] args)

Calls test1 and test2 in a loop. Tracer will complain whenever some call takes longer than 3 seconds