程序包 java.lang.invoke

类 VolatileCallSite

java.lang.Object

java.lang.invoke.CallSite

java.lang.invoke.VolatileCallSite

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.

In other respects, a VolatileCallSite is interchangeable with MutableCallSite.

另请参阅:

MutableCallSite

构造器概要

构造器

构造器	说明
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.

方法概要

限定符和类型	方法	说明
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.

从类继承的方法 java.lang.invoke.CallSite

type

从类继承的方法 java.lang.Object

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

构造器详细资料

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.

参数:

type - the method type that this call site will have

抛出:

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.

参数:

target - the method handle that will be the initial target of the call site

抛出:

NullPointerException - if the proposed target is null

方法详细资料

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.

指定者:

getTarget 在类中 CallSite

返回:

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

另请参阅:

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.

指定者:

setTarget 在类中 CallSite

参数:

newTarget - the new target

抛出:

NullPointerException - if the proposed new target is null

WrongMethodTypeException - if the proposed new target has a method type that differs from the previous target

另请参阅:

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)
 

指定者:

dynamicInvoker 在类中 CallSite

返回:

a method handle which always invokes this call site's current target