On 3/15/19 5:14 PM, Claes Redestad wrote:
Hi Peter,
thanks for reviewing!
Interning arbitrary attribute names might have some unfortunate side-
effects,
You mean if the number of different names would get larger and larger on
a long-running JVM, the cache would grow without bounds?
I noticed that the Name constructor:
public Name(String name) {
this.hashCode = hash(name);
this.name = name.intern();
}
...interns the String name. Do interned strings have a weak cache or are
they kept for the entire life of JVM?
Regards, Peter
but a tiny - maybe one or two element - cache might be
sufficient to keep the churn low in practice.
Name and SHA1-Digest are the most commonly repeated non-constant
attribute, generated by the jarsigner tool. Often appearing many times
in a single manifest. I also added SHA-256-Digest because that's what
you'd typically get if you signed a JAR file today.
/Claes
On 2019-03-15 17:07, Peter Levart wrote:
Hi Claes,
If you have observed memory churn allocating Name objects when
reading jar files, then perhaps we could do something to the logic of
Attributes class so that lazily allocated Name(s) would get interned
too?
As a separate change of course. This looks good as is.
Regards, Peter
On 3/15/19 2:45 PM, Claes Redestad wrote:
Hi,
On 2019-03-14 18:20, Claes Redestad wrote:
On 2019-03-14 18:13, Alan Bateman wrote:
For the current webrev then I'm concerned it is brings back legacy
attributes. The concept of "installed optional packages" was
removed in Java SE 9, as was the ability for JAR packaged applets
to trigger downloading of optional packages. I don't think the
later was ever implemented in the JDK so surprising that we are
finding JAR files with those attributes now. If we can prune that
down then I think the changes will be okay.
Ok. I stumbled on some new test issues in SA with this patch, so I'll
need to pause this one for a while anyhow.
I have a solution to the heap dump issues out for review[1], so I've
cleaned up this patch, verified the failing tests pass locally and
am running both through tier1-3:
http://cr.openjdk.java.net/~redestad/8214712/open.01/
Thanks!
/Claes
[1]
http://mail.openjdk.java.net/pipermail/serviceability-dev/2019-March/027455.html
