org.dynalang.dynalink.linker

Interface GuardingDynamicLinker

All Known Subinterfaces:

TypeBasedGuardingDynamicLinker

All Known Implementing Classes:

BeansLinker, BottomGuardingDynamicLinker, CompositeGuardingDynamicLinker, CompositeTypeBasedGuardingDynamicLinker

public interface GuardingDynamicLinker

The base interface for language-specific dynamic linkers. Such linkers always have to produce method handles with guards, as the validity of the method handle for calls at a call site inevitably depends on some condition (at the very least, it depends on the receiver belonging to the language runtime of the linker). Language runtime implementors will normally implement one for their own language, and declare it in the META-INF/services/org.dynalang.dynalink.linker.GuardingDynamicLinker file within their JAR file.

Author:

Attila Szegedi

Method Summary

Methods

Modifier and Type	Method and Description
GuardedInvocation	getGuardedInvocation(LinkRequest linkRequest, LinkerServices linkerServices) Creates a guarded invocation appropriate for a particular invocation with the specified arguments at a call site.

Method Detail

getGuardedInvocation

GuardedInvocation getGuardedInvocation(LinkRequest linkRequest,
                                     LinkerServices linkerServices)
                                       throws Exception

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

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.

Throws:

Exception - if the operation fails for whatever reason