public class VolatileCallSite
extends CallSite 

See Also:

MutableCallSite

• Constructor Summary

  Constructors

  Constructor and Description
  VolatileCallSite (MethodHandle target) Creates a call site with a volatile binding to its target.
  VolatileCallSite (MethodType type) Creates a call site with a volatile binding to its target.

• Method Summary

  Methods

  Modifier and Type	Method and Description
  MethodHandle	dynamicInvoker () Produces a method handle equivalent to an invokedynamic instruction which has been linked to this call site.
  MethodHandle	getTarget () Returns the target method of the call site, which behaves like a volatile field of the VolatileCallSite.
  void	setTarget (MethodHandle newTarget) Updates the target method of this call site, as a volatile variable.

  • Methods inherited from class java.lang.invoke.CallSite

    type

  • Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

• 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