Hi,
Module system implementation refresh 2017/2 (JDK-8173393) introduced new
API method AccessibleObject::canAccess which can be used to test if the
caller has access to the reflected member (with possible target object
argument for instance members). The implementation of this method, after
some parameter validation checks, delegates directly to
jdk.internal.reflect.Reflection::verifyMemberAccess. This is
sub-optimal. Co-located internal method AccessibleObject::checkAccess
also delegates to Reflection::verifyMemberAccess, but it also uses a
one-element cache of access-check decision, which greatly speeds up
repeated calls by the same caller to the same reflected member. The
cache could be shared between those two methods which would improve
performance of code idioms like this:
if (member.canAccess(target) || member.trySetAccessible()) {
member.invoke(....);
...
} else {
...
}
Here's a proposed patch to improve this new method's performance:
http://cr.openjdk.java.net/~plevart/jdk9-dev/8177086_AccessibleObject.canAccess.cache/webrev.01/
The corresponding jira issue is:
https://bugs.openjdk.java.net/browse/JDK-8177086
I don't know whether this should go to jdk9 or perhaps later to jdk9u,
since this is new API that only came into existence 1 month ago and this
patch improves its implementation. Should It perhaps go to jake repo
1st? Presented patch is made against current jdk9/jdk repo.
Regards, Peter
