Any time user want to evaluate variable or change value, jdb will restore functions stack.

class FunctionStack {

    static int amountOfCalls;

    FunctionStack (int _amountOfCalls) {
        amountOfCalls = _amountOfCalls;
    }

    int MakeStack(int stLevel) {
        if (stLevel < amountOfCalls)
            this.MakeStack(++stLevel);
        System.out.println("Level: " + stLevel);
        return stLevel;
    }
    
    public static void main(String args[]) {
        FunctionStack fs = new FunctionStack(20);
        fs.MakeStack(0);
    }
}

To reproduce:

stop at FunctionStack:14
run FunctionStack
where
up
up
up
up
where
eval stLevel
where