Exception while trying to acquire a JMH lock

Question

This code was working fine. On restarting the computer, it gives me the error:

ERROR: org.openjdk.jmh.runner.RunnerException: 
ERROR: Exception while trying to acquire the JMH lock (C:\WINDOWS\/jmh.lock): 
Access is denied, exiting. Use -Djmh.ignoreLock=true to forcefully continue.
at org.openjdk.jmh.runner.Runner.run(Runner.java:213)
at org.openjdk.jmh.Main.main(Main.java:71)

Google-int the error didn't help. Can someone tell me how to fix it?

@State(Scope.Thread)
public class test {
    public ConcurrentHashMap<String,Integer> i = new ConcurrentHashMap<String, Integer>(10000);
    public ArrayList<String> k = new ArrayList<String>(10000);
    public int p=0;

public void setup(){
    for(int m=0;m<1000;m++){
        int j=ThreadLocalRandom.current().nextInt(0,10000);
        String jk=Integer.toString(j);
        k.add(jk);
        i.put(jk,j);
    }
}

@Benchmark
@BenchmarkMode(Mode.Throughput)
@OutputTimeUnit(TimeUnit.MILLISECONDS)
@Warmup(iterations = 3)
@Measurement(iterations = 5)
public void putKey(){
    int n=ThreadLocalRandom.current().nextInt(0,10000);
    String nk=Integer.toString(n);
    k.add(nk);
    i.put(nk,n);
}

@Benchmark
@BenchmarkMode(Mode.Throughput)
@OutputTimeUnit(TimeUnit.MILLISECONDS)
@Warmup(iterations = 3)
@Measurement(iterations = 5)
public int getKey(){
    p=ThreadLocalRandom.current().nextInt(0,10000);
    p=p%k.size();
    return i.get(k.get(p));
}
public static void main(String[] args) throws RunnerException{
    Options opt = new OptionsBuilder()
            .include(".*" + test.class.getSimpleName() + ".*")
            .forks(1)
            .build();
    new Runner(opt).run();
}

}

Marcimarcia

Do you have write permissions in your c drive windows folder? – Piatt

@SauravSircar Did you try use -Djmh.ignoreLock=true? You can also look at this post – Moneymaking

Have you tried do manually delete the C:\WINDOWS\/jmh.lock file ? – Koran

@KoustavRay How do I do that? Sorry I'm quite new at Java. – Marcimarcia

@AlexandreCartapanis I'm unable to find it. – Marcimarcia

tried to show hidden files ? – Koran

@AlexandreCartapanis Yup. – Marcimarcia

Note that the error says "access denied" – Koran

Try creating a new file in that same location – Piatt

Answer 1

There are 2 solutions:

• add the TMP environment variable in the plugin configuration and point it to any writeable directory.

• run idea64.exe as Administrator

See https://github.com/artyushov/idea-jmh-plugin/issues/19

Fusionism

Answer 2

I encountered this same error message using the Gradle (command-line) on Windows. (I needed to pass --stacktrace to find the root-cause error message.)

In my case it was due to the following issue:

https://github.com/artyushov/idea-jmh-plugin/issues/19

And the solution was simply to bump the version of the jmh-gradle-plugin. Minimum required versions are documented here:

https://github.com/melix/jmh-gradle-plugin

Scary