java.lang.invoke

Class VolatileCallSite

Table des matières

  • public class VolatileCallSite
extends CallSite
    A VolatileCallSite is a CallSite whose target acts like a volatile variable. An invokedynamic instruction linked to a VolatileCallSite sees updates to its call site target immediately, even if the update occurs in another thread. There may be a performance penalty for such tight coupling between threads.

    Unlike MutableCallSite, there is no syncAll operation on volatile call sites, since every write to a volatile variable is implicitly synchronized with reader threads.

    In other respects, a VolatileCallSite is interchangeable with MutableCallSite.

    See Also:
    MutableCallSite

    • Constructor Detail

      • VolatileCallSite

        public VolatileCallSite(MethodType type)
        Creates a call site with a volatile binding to its target. The initial target is set to a method handle of the given type which will throw an IllegalStateException if called.
        Parameters:
        type - the method type that this call site will have
        Throws:
        NullPointerException - if the proposed type is null

      • VolatileCallSite

        public VolatileCallSite(MethodHandle target)
        Creates a call site with a volatile binding to its target. The target is set to the given value.
        Parameters:
        target - the method handle that will be the initial target of the call site
        Throws:
        NullPointerException - if the proposed target is null

    • Method Detail

      • getTarget

        public final MethodHandle getTarget()
        Returns the target method of the call site, which behaves like a volatile field of the VolatileCallSite.

        The interactions of getTarget with memory are the same as of a read from a volatile field.

        In particular, the current thread is required to issue a fresh read of the target from memory, and must not fail to see a recent update to the target by another thread.

        Specified by:
        getTarget in class CallSite
        Returns:
        the linkage state of this call site, a method handle which can change over time
        See Also:
        setTarget(java.lang.invoke.MethodHandle)

      • setTarget

        public void setTarget(MethodHandle newTarget)
        Updates the target method of this call site, as a volatile variable. The type of the new target must agree with the type of the old target.

        The interactions with memory are the same as of a write to a volatile field. In particular, any threads is guaranteed to see the updated target the next time it calls getTarget.

        Specified by:
        setTarget in class CallSite
        Parameters:
        newTarget - the new target
        Throws:
        NullPointerException - if the proposed new target is null
        WrongMethodTypeException - if the proposed new target has a method type that differs from the previous target
        See Also:
        getTarget()

      • dynamicInvoker

        public final MethodHandle dynamicInvoker()
        Produces a method handle equivalent to an invokedynamic instruction which has been linked to this call site.

        This method is equivalent to the following code: 

         MethodHandle getTarget, invoker, result;
 getTarget = MethodHandles.publicLookup().bind(this, "getTarget", MethodType.methodType(MethodHandle.class));
 invoker = MethodHandles.exactInvoker(this.type());
 result = MethodHandles.foldArguments(invoker, getTarget)
        Specified by:
        dynamicInvoker in class CallSite
        Returns:
        a method handle which always invokes this call site's current target

Traduction non disponible

Les API Java ne sont pas encore traduites en français sur l'infobrol. Seule la version anglaise est disponible pour l'instant.

Document créé le 11/06/2005, dernière modification le 04/03/2020
Source du document imprimé : https://www.gaudry.be/java-api-rf-java/lang/invoke/VolatileCallSite.html

L'infobrol est un site personnel dont le contenu n'engage que moi. Le texte est mis à disposition sous licence CreativeCommons(BY-NC-SA). Plus d'info sur les conditions d'utilisation et sur l'auteur.

Références

  1. Consulter le document html Langue du document :fr Manuel PHP : https://docs.oracle.com

Ces références et liens indiquent des documents consultés lors de la rédaction de cette page, ou qui peuvent apporter un complément d'information, mais les auteurs de ces sources ne peuvent être tenus responsables du contenu de cette page.
L'auteur de ce site est seul responsable de la manière dont sont présentés ici les différents concepts, et des libertés qui sont prises avec les ouvrages de référence. N'oubliez pas que vous devez croiser les informations de sources multiples afin de diminuer les risques d'erreurs.

Table des matières Haut