[Soot-list] CuncurrentModificationException
Eric Bodden
eric.bodden at mail.mcgill.ca
Wed Aug 20 12:09:47 EDT 2008
wjtp is a whole-program pack. Therefore you have to use Soot's -w
option to enable this pack.
Eric
2008/8/20 Bashar Al Rawi <brawi at umich.edu>:
> So, I have created this class:
>
> public class ClassTransformer extends SceneTransformer {
> private ClassTransformer() {
> }
>
> public static ClassTransformer v() {
> return instance;
> }
>
> protected void internalTransform(String arg0, Map arg1) {
> // TODO Auto-generated method stub
> System.out.println("SSSSSSSSSSSSS");
> Iterator it = Scene.v().getApplicationClasses().snapshotIterator();
>
> while(it.hasNext()){
> SootClass sc = (SootClass) it.next();
> System.out.println(sc);
> instrumentSelfRef(sc);
> System.out.println(sc.getMethods());
> }
> }
> }
>
> and in my main method, I have added the following:
>
> PackManager.v().getPack("wjtp").add(
> new Transform("wjtp.ClassTransformer",
> ClassTransformer.v()));
>
> I get the following output:
> Transforming tracer.benchmarks.MyThread...
> Transforming tracer.benchmarks.Toy1...
> Writing to sootOutput\tracer\benchmarks\MyThread.class
> Writing to sootOutput\tracer\benchmarks\Toy1.class
>
> So, basically it does not NOT print out the "SSSSSSSSSSSSSSSS", which means
> it never executes internalTransform. But, when I add the line:
> ClassTransformer.v().transform(); it works. Can you tell me why
> "internalTransform" is not called when I add it to "wjtp"?
>
>
> Many thanks.
>
>
> On Wed, Aug 20, 2008 at 10:05 AM, Bashar Al Rawi <brawi at umich.edu> wrote:
>>
>> 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
>
>
>
> --
> Bashar
>
--
Eric Bodden
Sable Research Group
McGill University, Montréal, Canada
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