On 11/1/18 10:01 AM, Sean Mullan wrote:
Some of the copyrights need to be updated to 2018.
Fixed.
All else looks good to me as I had reviewed an earlier version of this
before. We have talked about doing this for a while now, so I am
finally glad we and are able to pretty much eliminate one of the more
common SecurityManager related hot-spots and give a performance boost
to applications that don't use the SM as well.
Thanks Sean.
dl
--Sean
On 10/31/18 6:23 PM, dean.l...@oracle.com wrote:
https://bugs.openjdk.java.net/browse/JDK-8212605
http://cr.openjdk.java.net/~dlong/8212605/webrev.1
This change implements AccessController.doPrivileged in Java. This
gives a performance improvement while also being useful to Project
Loom by removing the Java --> native --> Java transition. One reason
doPrivileged has historically been in native is because of the need
to guarantee the cleanup of the privileged context when doPrivileged
returns. To do that in Java, the information that
AccessController.getContext needs is pushed onto the Java stack as
arguments to a method that getContext will recognize during its stack
walk. This allows us to remove the native privileged stack while
guaranteeing that the privileged context goes away when the method
returns.
Tested with tier1-tier3 hotspot and jdk tests and JCK
api/java_security tests. For the first few rounds of testing, I kept
the old native privileged stack and compared the results of the old
and new implementations for each getContext call, which did catch
some early bugs. The changes were also examined by internal security
experts and run through additional internal security tests.
The improvement on this [1] doPrivileged microbenchmark is
approximate 50x.
There is no attempt to optimize getContext() or security permission
checks in this change, however, this is intended to be a first step
towards other possible improvements, for example those proposed here
[2].
dl
[1]
http://hg.openjdk.java.net/code-tools/jmh-jdk-microbenchmarks/file/fc4783360f58/src/main/java/org/openjdk/bench/java/security/DoPrivileged.java
[2]
http://mail.openjdk.java.net/pipermail/security-dev/2017-December/016627.html
