org.dynalang.dynalink.support

Class BottomGuardingDynamicLinker

java.lang.Object

org.dynalang.dynalink.support.BottomGuardingDynamicLinker

All Implemented Interfaces:

GuardingDynamicLinker, TypeBasedGuardingDynamicLinker

public class BottomGuardingDynamicLinker
extends Object
implements TypeBasedGuardingDynamicLinker

A linker that can't link any call site. Only used internally by CompositeTypeBasedGuardingDynamicLinker. Can be used by other language runtimes if they need it though.

Author:

Attila Szegedi

Field Summary

Fields

Modifier and Type	Field and Description
static BottomGuardingDynamicLinker	INSTANCE The sole instance of this stateless linker.

Method Summary

Modifier and Type	Method and Description
boolean	canLinkType(Class<?> type) Returns true if the linker can link an invocation where the first argument (receiver) is of the specified type.
GuardedInvocation	getGuardedInvocation(LinkRequest linkRequest, LinkerServices linkerServices) Creates a guarded invocation appropriate for a particular invocation with the specified arguments at a call site.

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE

public static final BottomGuardingDynamicLinker INSTANCE

The sole instance of this stateless linker.

Method Detail

canLinkType

public boolean canLinkType(Class<?> type)

Description copied from interface: TypeBasedGuardingDynamicLinker

Returns true if the linker can link an invocation where the first argument (receiver) is of the specified type.

Specified by:

canLinkType in interface TypeBasedGuardingDynamicLinker

Parameters:

type - the type to link

Returns:

true if the linker can link calls for the receiver type, or false otherwise.

getGuardedInvocation

public GuardedInvocation getGuardedInvocation(LinkRequest linkRequest,
                                     LinkerServices linkerServices)

Description copied from interface: GuardingDynamicLinker

Creates a guarded invocation appropriate for a particular invocation with the specified arguments at a call site.

Specified by:

getGuardedInvocation in interface GuardingDynamicLinker

Parameters:

linkRequest - the object describing the request for linking a particular invocation

linkerServices - linker services

Returns:

a guarded invocation with a method handle suitable for the arguments, as well as a guard condition that if fails should trigger relinking. Must return null if it can't resolve the invocation. If the returned invocation is unconditional (which is actually quite rare), the guard in the return value can be null. The invocation can also have a switch point for asynchronous invalidation of the linkage. If the linker does not recognize any native language runtime contexts in arguments, or does recognize its own, but receives a call site descriptor without its recognized context in the arguments, it should invoke LinkRequest.withoutRuntimeContext() and link for that.