Great, thanks for your work.
> Hi Norris
> Dived into your code. awesome job.
> here is what i did to make this work ( at least partially...) , I added this
> function to the CodeGen class :
> private void addInstructionCount(int count){
> cfw.addALoad(contextLocal);
> cfw.addPush(count);
> addScriptRuntimeInvoke("addInstructionCount",
> "(Lorg/mozilla/javascript/Context;"
> +"I)V");
> }
> And this function to the ScriptRuntime class :
> public static void addInstructionCount(Context cx , int
> instructionsToAdd)
> {
> cx.instructionCount += instructionsToAdd;
> if (cx.instructionCount > cx.instructionThreshold)
> {
> cx.observeInstructionCount(cx.instructionCount);
> cx.instructionCount = 0;
> }
> }
> also , I have created an boolean field to the CompilerEnviros ( boolean
> generateObserverCount ) that initializes itself from a similar field in The
> Context class that. So in any place that i want to add an instruction count
> in the generated class i will put this code :
> (class CodeGen )
> if (this.compilerEnv.generateObserverCount())
> this.addInstructionCount(1);
> Let me know if you think it will work out , plus , on which location in
> CodeGen i should put this . also , I'd be happy to contribute in any way
> that you think appropriate ( writing unit tests etc )
> Cheers
> On 9/25/07, Norris Boyd <norrisb...@gmail.com> wrote:
> > On Sep 24, 9:11 pm, "ohad.serfaty" <ohad.serf...@gmail.com> wrote:
> > > Hi All
> > > I have been playing a lot with rhino lately , I have some questions
> > > regarding script optimization
> > > 1. are there any stats as to how the optimizer reduces the runtime of
> > > javascript ?
> > There's the JavaScript speed tests here:
> >http://ejohn.org/apps/js-speed/results/.
> > I've modified them to run with Rhino interpreted as well, although I
> > haven't had the time to get accurate results and in a format to
> > report. For these kind of compute-intensive tasks, compiling to Java
> > bytecodes is a significant win. Not sure how typical a workload this
> > would be, however. I'd expect most Rhino applications to spend most
> > time in library routines or I/O.
> > > 2. is it faster to compile a script that will be executed a lot of
> > > times , and then exec the Script object ?
> > Yes, you then amortize the compilation costs across multiple script
> > executions.
> > > is there any difference when
> > > i use the -1 optimization ?
> > Yes, -1 means use Rhino's builtin interpreter. 0 and above mean
> > compile to Java classes.
> > > 3. stopping the script in higher optimized code is impossible under
> > > the current rhino conditions. I can use the Thread.stop() method but
> > > am reluctant to do so as it is unsafe. Is it possible to have a stop()
> > > or interrupt() function to stop execution of a malicious script thats
> > > running in highly optimized context ?
> > You're right that this is a feature request and a good one. The right
> > way to do this is to implement Context.observeInstructionCount for
> > compiled mode. There would need to be some way to indicate to the
> > compiler that you'd like to observe the count, and then compile in
> > callbacks from the generated Java classes at key points (backwards
> > jumps, function returns) that increment a counter by some value that
> > approximates the count of executed Java instructions. The runtime
> > could then monitor these like is already done for interpreted scripts.
> > I don't know when I'll get to this (patches accepted!), so in the
> > meantime I'd recommend using interpreted mode if this feature is
> > important to your application.
> > --Norris
> > > Thanks in advance
> > _______________________________________________
> > dev-tech-js-engine mailing list
> > dev-tech-js-eng...@lists.mozilla.org
> >https://lists.mozilla.org/listinfo/dev-tech-js-engine
> --
> Ohad Serfaty
> Dapper -http://www.dapper.net
