How to kill a JUnit test run in Eclipse that has entered an infinte loop

Question

I have some Java code that I am unit testing using JUnit, running inside Eclipse (Neon). It so happens that some code under test has a bug in it, causing it to enter an infinite loop. The JUnit run then, of course, does not finish. How do I kill the test run?

The button for stopping the test run ("Stop JUnit Test Run") does not work well: the GUI seems to think that it has stopped the test run, but a look at the CPU activity (using top, for example), shows that a Java thread is still running. I can kill the thread myself by sending it a kill signal. But that seems a kludge and is inconvenient. Is there a better way, available within Eclipse itself?

Matthew Farwell · Accepted Answer · 2013-08-05T13:58:18.487

7

Kill it from the console view, using the red button. This stops the process.

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Stopping it from the junit view only asks it to stop.

edited Aug 05 '13 at 13:58

answered Aug 05 '13 at 12:30

Matthew Farwell

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Thomas Fritsch · Answer 2 · 2017-06-27T12:19:06.823

5

You can handle such things with JUnit by specifying a time-out within the @Test annotation. For example:

// Simple test-case which will always fail with time-out
@Test(timeout = 1000 * 60) throws Exception // 60 seconds 
public void testSomething() {
    for (int i = 0; i < 100; i++) {  // 100 seconds
        Thread.sleep(1000);
    }
}

If your test method doesn't finish on time, then JUnit will interrupt it and report a test failure. For the example above it will be:

java.lang.Exception: test timed out after 60000 milliseconds
    at java.lang.Thread.sleep(Native Method)
    at my.package.Test1.testSomething(Test1.java:12)

edited Jun 27 '17 at 12:19

answered Jun 27 '17 at 11:01

Thomas Fritsch

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Useful if you anticipate a failure of a particular test *might* cause an infinite loop. Not so useful if you have no good reason to suspect that, or a subsequent attempted re-factoring introduces an infinite loop. – Raedwald Jun 27 '17 at 11:58
@Raedwald Well, I would turn around your reasoning and annotate *every* test method with `@Test(timeout=60000)` (or some other arbitrarily high timeout) even if I do *not* have any reason to expect an infinite loop. – Thomas Fritsch Jun 27 '17 at 12:18
Adding that to *every* test is a code smell, I think. – Raedwald Jun 27 '17 at 14:34
@Raedwald Yes indeed, it looks smelly. A better way would be to set a default time-out as described in this [answer to "Set JUnit timeout in eclipse"](https://stackoverflow.com/questions/4097821/set-junit-timeout-in-eclipse/13600361#13600361). – Thomas Fritsch Jun 27 '17 at 16:16

score 0 · Answer 3 · answered Aug 05 '13 at 14:07

First, try Matthew Farwell's answer. If that doesn't work then you have to go to your processes running (ctrl+shift+esc on windows, then processes tab) and select the java.exe task, then end process. In the event you ever need to kill eclipse, it's javaw.exe

How to kill a JUnit test run in Eclipse that has entered an infinte loop

3 Answers3