Incorrect lazy initialization

user_471149 0
Viewed 38759

Findbug told me that I use incorrect lazy initialization.

public static Object getInstance() {
    if (instance != null) {
        return instance;
    }

    instance = new Object();
    return instance;
}

I don't see anything wrong here. Is it wrong behaviour of findbug, or I missed something?

findbugs java
8 Answers

Thanks to John Klehm for posted sample

also may try to assign object instance in sychronised block directly

synchronized (MyCurrentClass.myLock=new Object())

i.e.

private static volatile Object myLock = new Object();

public static Object getInstance() {
    if (instance == null) { // avoid sync penalty if we can
        synchronized (MyCurrentClass.myLock**=new Object()**) { // declare a private static Object to use for mutex
            if (instance == null) {  // have to do this inside the sync
                instance = new Object();
            }
        }
    }

    return instance;

}
user_12528870
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