Package io.netty.util

Interface Attribute<T>

  • Type Parameters:
    T - the type of the value it holds.
    public interface Attribute<T>
    An attribute which allows to store a value reference. It may be updated atomically and so is thread-safe.

    • Method Detail

      • get

        T get()
        Returns the current value, which may be null

      • set

        void set​(T value)
        Sets the value

      • getAndSet

        T getAndSet​(T value)
        Atomically sets to the given value and returns the old value which may be null if non was set before.

      • setIfAbsent

        T setIfAbsent​(T value)
        Atomically sets to the given value if this Attribute's value is null. If it was not possible to set the value as it contains a value it will just return the current value.

      • compareAndSet

        boolean compareAndSet​(T oldValue,
                      T newValue)
        Atomically sets the value to the given updated value if the current value == the expected value. If it the set was successful it returns true otherwise false.

      • remove

        @Deprecated
void remove()
        Deprecated.
        please consider using set(Object) (with value of null).
        Removes this attribute from the AttributeMap. Subsequent get() calls will return @{code null}. If you only want to remove the value and clear the Attribute while still keep it in AttributeMap use set(Object) with a value of null.

        Be aware that even if you call this method another thread that has obtained a reference to this Attribute via AttributeMap.attr(AttributeKey) will still operate on the same instance. That said if now another thread or even the same thread later will call AttributeMap.attr(AttributeKey) again, a new Attribute instance is created and so is not the same as the previous one that was removed. Because of this special caution should be taken when you call remove() or getAndRemove().