How to check if thread holds the monitor in IntelliJ?

Question

While working on IntelliJ , I am unable to check that if the thread is holding the lock or not.

On eclipse GUI there is a lock like icon against the thread , telling us that it is holding that lock.

In below code snapshot, my thread is at notifyElementAdded() and holding the lock however, in a thread stack there is no such Icon or intimation from Intellij

So my question is how to check the same on IntelliJ GUI.

Answer 1

There is actually a boolean attribute to the Thread class in Java - Thread.holdsLock(). To get the name of the thread which holds the monitor you can use the code example below:

public static long getMonitorOwner(Object obj)
{
    if (Thread.holdsLock(obj)) 
    {
        return Thread.currentThread().getId();
    }
}

Answer 2

I don't think there is a similar functionality. But you can still check by getting the dump

You can click on Get Thread Dump in Debug window and then you can see the locked in the log to see that the thread is actually holding the lock

Answer 3

Create a custom variable in the Intellij debugging console using the plus button as shown in the image below.

Now every time you run the code in the debug mode, this variable will be re-calculated at your all debug points.

I created a variable- Thread.holdsLock(AwsS3ClientHelper.class) since I was acquiring a lock on the class itself. You can write any variable of your choice there. In your particular case, it will be Thread.holdsLock(observers).