Class CompositeTypeBasedGuardingDynamicLinker
java.lang.Object
jdk.dynalink.linker.support.CompositeTypeBasedGuardingDynamicLinker
- All Implemented Interfaces:
-
GuardingDynamicLinker
,TypeBasedGuardingDynamicLinker
public class CompositeTypeBasedGuardingDynamicLinker extends Object implements TypeBasedGuardingDynamicLinker
A composite type-based guarding dynamic linker. When a receiver of a not yet seen class is encountered, all linkers are queried sequentially on their
TypeBasedGuardingDynamicLinker.canLinkType(Class)
method. The linkers returning true are then bound to the class, and next time a receiver of same type is encountered, the linking is delegated to those linkers only, speeding up dispatch.Constructor Summary
Constructor | Description |
---|---|
CompositeTypeBasedGuardingDynamicLinker |
Creates a new composite type-based linker. |
Method Summary
Modifier and Type | Method | Description |
---|---|---|
boolean |
canLinkType |
Returns true if at least one of the composite linkers returns true from TypeBasedGuardingDynamicLinker.canLinkType(Class) for the type. |
GuardedInvocation |
getGuardedInvocation |
Creates a guarded invocation appropriate for a particular invocation with the specified arguments at a call site. |
static List<GuardingDynamicLinker> |
optimize |
Optimizes a list of type-based linkers. |
Constructor Details
CompositeTypeBasedGuardingDynamicLinker
public CompositeTypeBasedGuardingDynamicLinker(Iterable<? extends TypeBasedGuardingDynamicLinker> linkers)
Creates a new composite type-based linker.
- Parameters:
-
linkers
- the component linkers - Throws:
-
NullPointerException
- iflinkers
or any of its elements are null.
Method Details
canLinkType
public boolean canLinkType(Class<?> type)
Returns true if at least one of the composite linkers returns true from
TypeBasedGuardingDynamicLinker.canLinkType(Class)
for the type.- Specified by:
-
canLinkType
in interfaceTypeBasedGuardingDynamicLinker
- Parameters:
-
type
- the type to link - Returns:
- true true if at least one of the composite linkers returns true from
TypeBasedGuardingDynamicLinker.canLinkType(Class)
, false otherwise.
getGuardedInvocation
public GuardedInvocation getGuardedInvocation(LinkRequest linkRequest, LinkerServices linkerServices) throws Exception
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 interfaceGuardingDynamicLinker
- 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 any number of switch points for asynchronous invalidation of the linkage, as well as a
Throwable
subclass that describes an expected exception condition that also triggers relinking (often it is faster to rely on an infrequent but expectedClassCastException
than on an always evaluatedinstanceof
guard). While the linker must produce an invocation with parameter types matching those in the call site descriptor of the link request, it should not try to match the return type expected at the call site except when it can do it with only the conversions that lose neither precision nor magnitude, seeLinkerServices.asTypeLosslessReturn(MethodHandle, MethodType)
for further explanation. - Throws:
-
Exception
- if the operation fails for whatever reason
optimize
public static List<GuardingDynamicLinker> optimize(Iterable<? extends GuardingDynamicLinker> linkers)
Optimizes a list of type-based linkers. If a group of adjacent linkers in the list all implement
TypeBasedGuardingDynamicLinker
, they will be replaced with a single instance of CompositeTypeBasedGuardingDynamicLinker
that contains them.- Parameters:
-
linkers
- the list of linkers to optimize - Returns:
- the optimized list
- Throws:
-
NullPointerException
- iflinkers
or any of its elements are null.
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https://docs.oracle.com/en/java/javase/17/docs/api/jdk.dynalink/jdk/dynalink/linker/support/CompositeTypeBasedGuardingDynamicLinker.html