On 20/01/2017 13:00, Rémy Maucherat wrote: > 2017-01-20 13:14 GMT+01:00 Mark Thomas <ma...@apache.org>: > >> Rory, >> >> We have a handful of instances where Tomcat currently needs to use >> reflection which are blocked when running on Java 9. >> >> Users can work-around these but it would probably be better if an >> alternative API was identified / provided to achieve the same results >> without reflection. >> >> There are currently three instances I am aware of. >> >> 1. Cleaning direct ByteBuffers >> To avoid OOME, we need to be able to trigger cleaning of a direct >> ByteBuffers. The code in question is at [1]. We need a way to trigger >> DirectByteBuffer.cleaner().clean() via a public API. >> > > Technically this is: https://bugs.openjdk.java.net/browse/JDK-8171377 > Essentially, we must now use > sun.misc.Unsafe.getUnsafe.invokeCleaner(byteBuffer). The problem is that we > cannot use reflection (Unsafe.getUnsafe is explicitly filtered out) and > there's also a security check which may or may not necessitate some extra > configuration.
We should be able to use JreCompat to handle this. Java 9 can use Unsafe since we know it will be there whereas Java 8 and earlier can continue with the original approach. Mark > >> >> 2. Cleaning thread local related memory leaks >> To fix application created memory leaks, we need to be able to clear >> thread locals associated with a given class loader from a thread. >> To be able to warn users they have a memory leak in their application, >> we need to be able to list the thread locals associated with a class >> loader for a thread. The relevant code is at [2]. >> >> 3. Cleaning RMI related memory leaks >> To fix application created memory leaks, we need to be able to clear RMI >> objects associated with a given class loader. >> To be able to warn users they have a memory leak in their application, >> we need to be able to list the RMI targets associated with a given >> classloader. The relevant code is at [3]. >> >> Any suggestions for alternative public APIs to achieve the same ends >> gratefully received. >> > > +1 > > Rémy > >> >> Kind regards, >> >> Mark >> >> >> [1] >> http://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/tomcat/util/buf/ >> ByteBufferUtils.java?diff_format=h&view=annotate#l38 >> >> [2] >> http://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/catalina/loader/ >> WebappClassLoaderBase.java?diff_format=h&view=annotate#l1823 >> >> [3] >> http://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/catalina/loader/ >> WebappClassLoaderBase.java?diff_format=h&view=annotate#l2058 >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: dev-unsubscr...@tomcat.apache.org >> For additional commands, e-mail: dev-h...@tomcat.apache.org >> >> > --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@tomcat.apache.org For additional commands, e-mail: dev-h...@tomcat.apache.org
