java.lang.Object
java.lang.invoke.CallSite
java.lang.invoke.MutableCallSite
jdk.dynalink.support.AbstractRelinkableCallSite
jdk.dynalink.support.ChainedCallSite
- All Implemented Interfaces:
RelinkableCallSite
public class ChainedCallSite extends AbstractRelinkableCallSite
A relinkable call site that implements a polymorphic inline caching strategy.
It remembers up to 8
GuardedInvocation
s it was linked with, and on
each relink request builds a cascading chain of method handles of one
invocation falling back to the next one. The number of remembered invocations
can be customized by overriding getMaxChainLength()
in a subclass.
When this call site is relinked with a new invocation and the length of the
chain is already at the maximum, it will throw away the oldest invocation.
Invocations with invalidated switch points and ones for which their
invalidating exception triggered are removed eagerly from the chain. The
invocations are never reordered; the most recently linked method handle is
always at the start of the chain and the least recently linked at its end.
The call site can be safely relinked on more than one thread concurrently.
Race conditions in linking are resolved by throwing away the
GuardedInvocation
produced on the losing thread without incorporating
it into the chain, so it can lead to repeated linking for the same arguments.-
Constructor Summary
Constructors Constructor Description ChainedCallSite(CallSiteDescriptor descriptor)
Creates a new chained call site. -
Method Summary
Modifier and Type Method Description protected int
getMaxChainLength()
The maximum number of method handles in the chain.Methods declared in class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods declared in interface jdk.dynalink.RelinkableCallSite
getDescriptor, initialize, relink, resetAndRelink
-
Constructor Details
-
ChainedCallSite
Creates a new chained call site.- Parameters:
descriptor
- the descriptor for the call site.
-
-
Method Details
-
getMaxChainLength
protected int getMaxChainLength()The maximum number of method handles in the chain. Defaults to 8. You can override it in a subclass if you need to change the value.- Returns:
- the maximum number of method handles in the chain. The return
value is checked, and if your override returns a value less than 1, a
RuntimeException
will be thrown.
-