Re: [aspectj-users] AspectJ overhead

[Wes Isberg <wes@xxxxxxxxxxxxxx>]

> I measured the overhead of my aspect and it adds 120% overhead!!!

Yes, thisJoinPoint is reflective and uses memory.
You might speed up the join point matching by using
staticly-determinable pointcuts -- e.g.,

from
     pointcut methodCall(Object o):  call(* *(..))
         && target(o) && !javaCode()  && !myTrace();
to
     pointcut methodCall():  call(!static * *(..))
         && !javaCode()  && !myTrace();

Then use thisJoinPoint.getTarget().

But how much time is the logging and how much is the 
aspect protocol to log?  Put another way, if you disable 
logging and String concatenation, does just the aspect
tracing protocol double the time your program takes 
to run?  That seems like the right measure of the overhead.

Wes

"Mohamed S. Mansour" wrote:
> 
> Hi,
> 
> I am writing an aspect to trace program execution. Basically, for each method
> call we want to log the caller, callee and values of formal arguments.
> 
> I measured the overhead of my aspect and it adds 120% overhead!!!
> 
> By stripping down my aspect, I found out that using thisJoinPoint is the culprit.
> 
> Is there an alternative aspect that causes less overhead?
> --
> Mohamed
> 
> aspect TraceAspect {
>     pointcut myTrace(): within(TraceAspect) || within(Trace);
>     pointcut javaCode(): within(java..*) || call(* java..*(..));
> 
>     // a point cut that matches any non-static method call.
>     pointcut methodCall(Object o):
>            call(* *(..))
>            && target(o)
>            && !javaCode()
>            && !myTrace();
> 
>     // a point cut that matches any static method call.
>     pointcut staticMethodCall():
>            call(static * *(..))
>            && !javaCode()
>            && !myTrace();
> 
>     before (): staticMethodCall() {
>        logCaller(thisJoinPoint);
>        logCallee(thisJoinPointStaticPart);
>     }
>     before (Object o): methodCall(o) {
>        logCaller(thisJoinPoint);
>        logCallee(thisJoinPointStaticPart, o);
>     }
>     //***********************************************//
>     private void logCaller(JoinPoint thisJoinPoint) {
>        SourceLocation loc = thisJoinPoint.getSourceLocation();
>        // add a log entry
> 
>        Object[] args = thisJoinPoint.getArgs();
>        for (int i=0; i<args.length; i++) {
>           // add a log entry
>        }
>     }
>     private void logCallee(JoinPoint.StaticPart thisJoinPointiStaticPart) {
> 
>        Signature sig = thisJoinPointiStaticPart.getSignature();
>        // add a log entry
>     }
>     private void logCallee(JoinPoint.StaticPart thisJoinPointStaticPart,
>                            Object target) {
>        Signature sig = thisJoinPointStaticPart.getSignature();
>        // add a log entry
>     }
>     //***********************************************//
> }
> 
> _______________________________________________
> aspectj-users mailing list
> aspectj-users@xxxxxxxxxxx
> http://dev.eclipse.org/mailman/listinfo/aspectj-users