Re: kawa and apache tomcat

[Damien MATTEI <Damien.Mattei@unice.fr>]

Hi Mathieu and Per,

sorry for my late answer but i was outside from office for few days,
thank you for your answers, i tried a patch on  the 2.A sources of kawa,  just have few problem to patch it ( i hadn't use patch command for more than a decade),hope it'es the good way:
 mattei@moita kawa-2.1]$ patch < servet.patch 
(Stripping trailing CRs from patch; use --binary to disable.)
can't find file to patch at input line 5
Perhaps you should have used the -p or --strip option?
The text leading up to this was:
--------------------------
|Index: gnu/kawa/servlet/KawaServlet.java
|===================================================================
|--- gnu/kawa/servlet/KawaServlet.java  (revision 8666)
|+++ gnu/kawa/servlet/KawaServlet.java  (working copy)
--------------------------
File to patch: gnu/kawa/servlet/KawaServlet.java 
patching file gnu/kawa/servlet/KawaServlet.java

and run make to compile kawa-2.1. jar with sources patched and add it in the netbeans project the way i do it all the day to make a .war application ,deployed it on the apache tomacat8 server
but the warnings are still here in the logs when i stop the application in tomcat8:
19-Jan-2016 11:47:28.131 SEVERE [http-nio-8080-exec-11] org.apache.catalina.loader.WebappClassLoaderBase.checkThreadLocalMapForLeaks The web application [Sidonie] created a ThreadLocal with key of type [java.lang.ThreadLocal] (value [java.lang.ThreadLocal@1758bda9]) and a value of type [gnu.mapping.CallContext] (value [gnu.mapping.CallContext@7c41808c]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
19-Jan-2016 11:47:28.131 SEVERE [http-nio-8080-exec-11] org.apache.catalina.loader.WebappClassLoaderBase.checkThreadLocalMapForLeaks The web application [Sidonie] created a ThreadLocal with key of type [gnu.mapping.ThreadLocation.ThreadLocalWithDefault] (value [gnu.mapping.ThreadLocation$ThreadLocalWithDefault@4f731308]) and a value of type [gnu.kawa.io.BinaryOutPort] (value [gnu.kawa.io.BinaryOutPort@3dcceb4c]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
19-Jan-2016 11:47:28.132 SEVERE [http-nio-8080-exec-11] org.apache.catalina.loader.WebappClassLoaderBase.checkThreadLocalMapForLeaks The web application [Sidonie] created a ThreadLocal with key of type [gnu.mapping.Environment.InheritedLocal] (value [gnu.mapping.Environment$InheritedLocal@6f2bbca9]) and a value of type [gnu.mapping.InheritingEnvironment] (value [#<environment http-nio-8080-exec-19>]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
19-Jan-2016 11:47:28.132 SEVERE [http-nio-8080-exec-11] org.apache.catalina.loader.WebappClassLoaderBase.checkThreadLocalMapForLeaks The web application [Sidonie] created a ThreadLocal with key of type [gnu.kawa.io.Path$1] (value [gnu.kawa.io.Path$1@4822bf88]) and a value of type [gnu.kawa.io.FilePath] (value [/root]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
19-Jan-2016 11:47:28.132 SEVERE [http-nio-8080-exec-11] org.apache.catalina.loader.WebappClassLoaderBase.checkThreadLocalMapForLeaks The web application [Sidonie] created a ThreadLocal with key of type [java.lang.InheritableThreadLocal] (value [java.lang.InheritableThreadLocal@2012835b]) and a value of type [kawa.standard.Scheme] (value [kawa.standard.Scheme@4f423c7d]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
19-Jan-2016 11:47:28.133 SEVERE [http-nio-8080-exec-11] org.apache.catalina.loader.WebappClassLoaderBase.checkThreadLocalMapForLeaks The web application [Sidonie] created a ThreadLocal with key of type [gnu.mapping.ThreadLocation.ThreadLocalWithDefault] (value [gnu.mapping.ThreadLocation$ThreadLocalWithDefault@12c104e2]) and a value of type [gnu.math.IntNum] (value [10]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.

unless you have others ideas i will continue because i do not think it is critical for now, if under some server load it was a problem i will notice it , anyway i'm melting and compiling java pure source with scheme code in java byte-code in kawa but also in bigloo (another scheme for C and that ahave also a java front end) so if there would be a real problem
 i can easily migrate kawa scheme routines in bigloo scheme routines if it was necessary. 

Regards,
Damien

Le Friday 15 January 2016 19:41:00, vous avez écrit :
> 
> On 01/15/2016 10:10 AM, Matthieu Vachon wrote:
> 
> 
> > This is not a problem in a standard JVM application because once the
> > application closes, nothing needs to be done. But in a container
> > environment, that's another story since thread a kinda re-used over
> > multiple requests. On high load, this can create huge memory leaks
> > depending on the what is actually stored.
> 
> As I understand it, the problem is not normal usage, but when a servlet is re-loaded.
> That creates a new ClassLoader, with a new set of Classes which causes
> some complicated interaction with the GC (which I don't properly understand).
> 
> In normal usage,with no ClassLoader churn, there might be some temporary leak,
> but the garbage should become collectible when a thread services a new request.
> 
> Could you try the attached patch?  I haven't actually tested it (except
> to verify it compiles).  Let me know if it makes a difference.
> It is possible it might *reduce* the number but not eliminate the
> warnings.  If so, we would be on the right track, though with more to do.
> 



-- 
Damien.Mattei@unice.fr, Damien.Mattei@oca.eu, UNS / OCA / CNRS