public class VolatileCallSite extends CallSite
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.
Unlike MutableCallSite, there is no
syncAll operation on volatile
call sites, since every write to a volatile variable is implicitly
synchronized with reader threads.
In other respects, a VolatileCallSite is interchangeable
with MutableCallSite.
MutableCallSite| Constructor and Description |
|---|
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.
|
| Modifier and Type | Method and Description |
|---|---|
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.
|
public VolatileCallSite(MethodType type)
IllegalStateException if called.type - the method type that this call site will haveNullPointerException - if the proposed type is nullpublic VolatileCallSite(MethodHandle target)
target - the method handle that will be the initial target of the call siteNullPointerException - if the proposed target is nullpublic final MethodHandle getTarget()
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.
getTarget in class CallSitesetTarget(java.lang.invoke.MethodHandle)public void setTarget(MethodHandle newTarget)
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.
setTarget in class CallSitenewTarget - the new targetNullPointerException - if the proposed new target is nullWrongMethodTypeException - if the proposed new target
has a method type that differs from the previous targetgetTarget()public final MethodHandle dynamicInvoker()
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)
dynamicInvoker in class CallSite Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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