[Soot-list] CuncurrentModificationException
Bashar Al Rawi
brawi at umich.edu
Wed Aug 20 10:05:09 EDT 2008
Thanks a lot. I will try it out and see what happens.
On Wed, Aug 20, 2008 at 9:38 AM, Eric Bodden <eric.bodden at mail.mcgill.ca>wrote:
> Soto calls a BodyTransformer in a loop, executing it for each body
> (each one that has a body, that is) of each application class. You
> modify the list of methods *while* this iteration happens. This is
> forbidden.
>
> The solution is to use a SceneTransformer instead, stick it in the
> wjtp pack, and then do this iteration manually in your code. Make sure
> that when you iterate over a class you actually iterate over a *copy*
> of the list of the methods in that class so that you can modify the
> actual list of methods concurrently.
>
> Eric
>
> 2008/8/20 Bashar Al Rawi <brawi at umich.edu>:
> > public class Instrumenter extends BodyTransformer {
> >
> > private boolean isObjectInstrumented = false;
> > private Set<SootClass> selfRefObjSet = new HashSet<SootClass>();
> > private static Instrumenter instance = new Instrumenter();
> >
> > private Instrumenter() {
> > }
> >
> > public static Instrumenter v() {
> > return instance;
> > }
> >
> > private SootClass getTopNonLibClass(SootClass s){
> > if(!selfRefObjSet.contains(s))
> > selfRefObjSet.add(s);
> > System.out.println("CURRENT CLASS: " + s);
> > if(s.getSuperclass().isLibraryClass())
> > return s;
> > return getTopNonLibClass(s.getSuperclass());
> > }
> >
> > private void instrumentSelfRef(SootClass sc) {
> > if (implementsSelfRef(sc))
> > return;
> > SootClass c = getTopNonLibClass(sc);
> > System.out.println("Top Non-Lib Class = " + c);
> > SootField objVar = new SootField("thisRef", RefType
> > .v("tracer.util.ObjVar"), Modifier.PUBLIC);
> > c.addField(objVar);
> > SootClass selfRefInterface = null;
> > if (!Scene.v().containsClass("tracer.util.SelfRef")) {
> > selfRefInterface = new SootClass("tracer.util.SelfRef",
> > Modifier.PUBLIC | Modifier.INTERFACE);
> > } else {
> > selfRefInterface =
> > Scene.v().getSootClass("tracer.util.SelfRef");
> > }
> > assert selfRefInterface.isInterface();
> > c.addInterface(selfRefInterface);
> > SootMethod m = new SootMethod("getSelfRef",
> > Arrays.asList(VoidType.v()),
> > RefType.v("tracer.util.ObjVar"),
> > Modifier.PUBLIC);
> > c.addMethod(m); //
> > -------------------------------------------------------> If I remove this
> > statement, everything works fine
> >
> > }
> > private void instrumentClasses(){
> > Iterator it =
> Scene.v().getApplicationClasses().snapshotIterator();
> > while(it.hasNext()){
> >
> > SootClass c = (SootClass) it.next();
> > instrumentSelfRef(c);
> > System.out.println(c.getMethods());
> > }
> > }
> > protected void internalTransform(Body body, String pn, Map map) {
> > System.out.println(Scene.v().getApplicationClasses());
> > if(!isObjectInstrumented){
> > isObjectInstrumented = true;
> > instrumentClasses();
> > }
> >
> >
> > instrumentStmt(body);
> >
> > }
> > }
> >
> >
> > Here is the output I got:
> >
> > Transforming tracer.benchmarks.Toy1...
> > [tracer.benchmarks.Toy1, tracer.benchmarks.MyThread]
> > CURRENT CLASS: tracer.benchmarks.Toy1
> > Top Non-Lib Class = tracer.benchmarks.Toy1
> > [<tracer.benchmarks.Toy1: void <init>()>, <tracer.benchmarks.Toy1: void
> > main(java.lang.String[])>, <tracer.benchmarks.Toy1: tracer.util.ObjVar
> > getSelfRef(void)>]
> > CURRENT CLASS: tracer.benchmarks.MyThread
> > Top Non-Lib Class = tracer.benchmarks.MyThread
> > [<tracer.benchmarks.MyThread: void <init>()>,
> <tracer.benchmarks.MyThread:
> > void run()>, <tracer.benchmarks.MyThread: int getX()>,
> > <tracer.benchmarks.MyThread: tracer.util.ObjVar getSelfRef(void)>]
> > method: <init>
> > r0 := @this: tracer.benchmarks.Toy1
> > Identity: r0 := @this: tracer.benchmarks.Toy1
> > specialinvoke r0.<java.lang.Object: void <init>()>()
> > return
> > Exception in thread "main" java.util.ConcurrentModificationException
> > at java.util.AbstractList$Itr.checkForComodification(Unknown Source)
> > at java.util.AbstractList$Itr.next(Unknown Source)
> > at soot.PackManager.runBodyPacks(PackManager.java:735)
> > at soot.PackManager.runBodyPacks(PackManager.java:451)
> > at soot.PackManager.runBodyPacks(PackManager.java:370)
> > at soot.PackManager.runPacks(PackManager.java:347)
> > at soot.Main.run(Main.java:203)
> > at soot.Main.main(Main.java:146)
> > at tracer.instrument.Instrumenter.main(Instrumenter.java:675)
> >
> >
> > Thanks a lot in advance.
> >
> >
> >
> > On Tue, Aug 19, 2008 at 11:21 PM, Richard L. Halpert
> > <richardlhalpert at gmail.com> wrote:
> >>
> >> Your explanation of the problem is rather vague. Please send code.
> >>
> >> -Richard
> >>
> >> On Tue, Aug 19, 2008 at 5:31 PM, Bashar Al Rawi <brawi at umich.edu>
> wrote:
> >>>
> >>> Hi,
> >>>
> >>> I am trying to add modify a class file by overwriting the
> >>> internalTransform method. However, whenever I add a new method to the
> class,
> >>> I get java.util.ConcurrentModificationException. I tried using
> >>> snapshotIterator, but its not working. Can you please tell me wat's
> >>> happening?
> >>>
> >>> Thanks
> >>>
> >>> --
> >>> Bashar
> >>>
> >>>
> >>> _______________________________________________
> >>> Soot-list mailing list
> >>> Soot-list at sable.mcgill.ca
> >>> http://mailman.cs.mcgill.ca/mailman/listinfo/soot-list
> >>>
> >>
> >
> >
> >
> > --
> > Bashar
> >
> > _______________________________________________
> > Soot-list mailing list
> > Soot-list at sable.mcgill.ca
> > http://mailman.cs.mcgill.ca/mailman/listinfo/soot-list
> >
> >
>
>
>
> --
> Eric Bodden
> Sable Research Group
> McGill University, Montréal, Canada
>
--
Bashar
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