Package org.drasyl.util

Class ConcurrentReference<T>

  • Type Parameters:
    T - the type of the ConcurrentReference object
    public class ConcurrentReference<T>
extends Object
    This class wraps an object of type T and serves as a write many read many memory. The advantage of this class is that all methods are lock free until a given condition is met for a write/update operation. Therefore this class requires less locks than an AtomicReference.

    • Method Detail

      • of

        public static <T> ConcurrentReference<T> of()
        Creates a new empty write many read many memory.
        Type Parameters:
        T - the type of the ConcurrentReference object
        Returns:
        an empty write many read many memory

      • of

        public static <T> ConcurrentReference<T> of​(T initialValue)
        Creates a new write many read many memory with the initial value of initialValue.
        Type Parameters:
        T - the type of the ConcurrentReference object
        Returns:
        a write many read many memory with the initial value of initialValue

      • computeIfAbsent

        public T computeIfAbsent​(Supplier<T> supplier)
        Sets the write many read many memory to the return value of supplier if value is Objects.isNull(Object). Otherwise, nothing happens. Blocks only if the if value is Objects.isNull(Object) and another thread tries to read or write concurrently the #value.
        Parameters:
        supplier - the value supplier
        Returns:
        the value after applying the supplier or the old value if not null

      • getValue

        public Optional<T> getValue()
        Returns:
        returns the internal optional that holds the current value

      • computeOnCondition

        public Optional<T> computeOnCondition​(Predicate<T> condition,
                                      UnaryOperator<T> unaryFunction)
        Sets the write many read many memory to the return value of unaryFunction if value fulfills the condition. Otherwise, nothing happens. Blocks only if condition is fulfilled and another thread tries to read or write concurrently the #value.
        Parameters:
        condition - the condition to test
        unaryFunction - the unary function to apply
        Returns:
        the value after applying the unaryFunction or the old value if condition not fulfilled

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class Object