Added in API level 26

VolatileCallSite

open class VolatileCallSite : CallSite

kotlin.Any
↳	java.lang.invoke.CallSite
	↳	java.lang.invoke.VolatileCallSite

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.

In other respects, a VolatileCallSite is interchangeable with MutableCallSite.

Summary

Public constructors
`VolatileCallSite(type: MethodType!)` Creates a call site with a volatile binding to its target.
`VolatileCallSite(target: MethodHandle!)` Creates a call site with a volatile binding to its target.

Public methods
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`.
open Unit	`setTarget(newTarget: MethodHandle!)` Updates the target method of this call site, as a volatile variable.

Inherited functions

From class CallSite

MethodType!

type()

Returns the type of this call site's target. Although targets may change, any call site's type is permanent, and can never change to an unequal type. The setTarget method enforces this invariant by refusing any new target that does not have the previous target's type.

Public constructors

VolatileCallSite

Added in API level 26

VolatileCallSite(type: MethodType!)

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`	MethodType!: the method type that this call site will have

Exceptions
`java.lang.NullPointerException`	if the proposed type is null

VolatileCallSite

Added in API level 26

VolatileCallSite(target: MethodHandle!)

Creates a call site with a volatile binding to its target. The target is set to the given value.

Parameters
`target`	MethodHandle!: the method handle that will be the initial target of the call site

Exceptions
`java.lang.NullPointerException`	if the proposed target is null

Public methods

dynamicInvoker

Added in API level 26

fun dynamicInvoker(): MethodHandle!

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:

<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)
  </code>

Return
`MethodHandle!`	a method handle which always invokes this call site's current target

getTarget

Added in API level 26

fun getTarget(): MethodHandle!

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.

Return
`MethodHandle!`	the linkage state of this call site, a method handle which can change over time

See Also

#setTarget

setTarget

Added in API level 26

open fun setTarget(newTarget: MethodHandle!): Unit

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.

Parameters
`newTarget`	MethodHandle!: the new target

Exceptions
`java.lang.NullPointerException`	if the proposed new target is null
`java.lang.invoke.WrongMethodTypeException`	if the proposed new target has a method type that differs from the previous target

See Also

#getTarget