Examples with GCObjectIterator com.ibm.j9ddr.vm29.j9.gc.GCObjectIterator used on opensource projects

Example 1 with GCObjectIterator

use of com.ibm.j9ddr.vm29.j9.gc.GCObjectIterator in project openj9 by eclipse.

the class RootScanner method scanNonCollectableObjectsInternal.

private void scanNonCollectableObjectsInternal(long memoryType) throws CorruptDataException {
    GCHeapRegionIterator regionIterator = GCHeapRegionIterator.from();
    while (regionIterator.hasNext()) {
        GCHeapRegionDescriptor region = regionIterator.next();
        if (new UDATA(region.getTypeFlags()).allBitsIn(memoryType)) {
            GCObjectHeapIterator objectIterator = GCObjectHeapIterator.fromHeapRegionDescriptor(region, true, false);
            while (objectIterator.hasNext()) {
                J9ObjectPointer object = objectIterator.next();
                doClassSlot(J9ObjectHelper.clazz(object));
                GCObjectIterator fieldIterator = GCObjectIterator.fromJ9Object(object, true);
                GCObjectIterator fieldAddressIterator = GCObjectIterator.fromJ9Object(object, true);
                while (fieldIterator.hasNext()) {
                    doNonCollectableObjectSlot(fieldIterator.next(), fieldAddressIterator.nextAddress());
                }
            }
        }
    }
}

Example 2 with GCObjectIterator

use of com.ibm.j9ddr.vm29.j9.gc.GCObjectIterator in project openj9 by eclipse.

the class LiveSetWalker method scanObject.

private static void scanObject(HashSet<J9ObjectPointer> visitedObjects, ObjectVisitor visitor, J9ObjectPointer object, VoidPointer address) {
    if (visitedObjects.contains(object)) {
        return;
    }
    if (!visitor.visit(object, address)) {
        return;
    }
    visitedObjects.add(object);
    try {
        GCObjectIterator objectIterator = GCObjectIterator.fromJ9Object(object, true);
        GCObjectIterator addressIterator = GCObjectIterator.fromJ9Object(object, true);
        while (objectIterator.hasNext()) {
            J9ObjectPointer slot = objectIterator.next();
            VoidPointer addr = addressIterator.nextAddress();
            if (slot.notNull()) {
                scanObject(visitedObjects, visitor, slot, addr);
            }
        }
        if (J9ObjectHelper.getClassName(object).equals("java/lang/Class")) {
            J9ClassPointer clazz = ConstantPoolHelpers.J9VM_J9CLASS_FROM_HEAPCLASS(object);
            // Iterate the Object slots
            GCClassIterator classIterator = GCClassIterator.fromJ9Class(clazz);
            GCClassIterator classAddressIterator = GCClassIterator.fromJ9Class(clazz);
            while (classIterator.hasNext()) {
                J9ObjectPointer slot = classIterator.next();
                VoidPointer addr = classAddressIterator.nextAddress();
                if (slot.notNull()) {
                    scanObject(visitedObjects, visitor, slot, addr);
                }
            }
            // Iterate the Class slots
            GCClassIteratorClassSlots classSlotIterator = GCClassIteratorClassSlots.fromJ9Class(clazz);
            GCClassIteratorClassSlots classSlotAddressIterator = GCClassIteratorClassSlots.fromJ9Class(clazz);
            while (classSlotIterator.hasNext()) {
                J9ClassPointer slot = classSlotIterator.next();
                VoidPointer addr = classSlotAddressIterator.nextAddress();
                J9ObjectPointer classObject = ConstantPoolHelpers.J9VM_J9CLASS_TO_HEAPCLASS(slot);
                if (classObject.notNull()) {
                    scanObject(visitedObjects, visitor, classObject, addr);
                }
            }
        }
    } catch (CorruptDataException e) {
        EventManager.raiseCorruptDataEvent("Corruption found while walking the live set, object: " + object.getHexAddress(), e, false);
    }
    visitor.finishVisit(object, address);
}

Example 3 with GCObjectIterator

use of com.ibm.j9ddr.vm29.j9.gc.GCObjectIterator in project openj9 by eclipse.

the class ObjectRefsCommand method dumpHeapReferences.

/**
 * Write the on heap references stanza to the output stream.
 * @param vm
 * @param targetObject
 * @param out
 * @throws CorruptDataException
 */
private void dumpHeapReferences(J9JavaVMPointer vm, J9ObjectPointer targetObject, PrintStream out) throws CorruptDataException {
    if (GCExtensions.isVLHGC()) {
        Table table = new Table("On Heap References");
        table.row("object (!j9object)", "field (!j9object)", "!mm_heapregiondescriptorvlhgc", "AC (type)");
        /* iterate over all heap regions */
        GCHeapRegionIterator regionIterator = GCHeapRegionIterator.from();
        while (regionIterator.hasNext()) {
            GCHeapRegionDescriptor region = regionIterator.next();
            if (region.containsObjects()) {
                MM_HeapRegionDescriptorVLHGCPointer vlhgcRegion = MM_HeapRegionDescriptorVLHGCPointer.cast(region.getHeapRegionDescriptorPointer());
                MM_AllocationContextTarokPointer currentAllocationContextTarok = vlhgcRegion._allocateData()._owningContext();
                /* iterate over all objects in region */
                GCObjectHeapIterator heapObjectIterator = region.objectIterator(true, false);
                while (heapObjectIterator.hasNext()) {
                    J9ObjectPointer currentObject = heapObjectIterator.next();
                    /* Iterate over the object's fields and list any that point at @ref targetObject */
                    GCObjectIterator fieldIterator = GCObjectIterator.fromJ9Object(currentObject, false);
                    while (fieldIterator.hasNext()) {
                        J9ObjectPointer currentTargetObject = fieldIterator.next();
                        if (currentTargetObject.eq(targetObject)) {
                            /* found a reference to our targetObject, add it to the table */
                            J9ClassPointer objectClass = J9ObjectHelper.clazz(currentObject);
                            String objectClassString = J9ClassHelper.getJavaName(objectClass);
                            table.row(currentObject.getHexAddress() + " //" + objectClassString, currentTargetObject.getHexAddress(), vlhgcRegion.getHexAddress(), currentAllocationContextTarok.getHexAddress() + " (" + currentAllocationContextTarok._allocationContextType() + ")");
                        }
                    }
                }
            }
        }
        table.render(out);
    }
}

Example 4 with GCObjectIterator

use of com.ibm.j9ddr.vm29.j9.gc.GCObjectIterator in project openj9 by eclipse.

the class CheckEngine method checkObjectHeap.

public int checkObjectHeap(J9ObjectPointer object, GCHeapRegionDescriptor regionDesc) {
    int result = J9MODRON_SLOT_ITERATOR_OK;
    boolean isDead = false;
    boolean isIndexable = false;
    J9ClassPointer clazz = null;
    try {
        if (ObjectModel.isDeadObject(object)) {
            /* this is a hole */
            result = checkJ9LinkedFreeHeader(GCHeapLinkedFreeHeader.fromJ9Object(object), regionDesc, _cycle.getCheckFlags());
            if (J9MODRON_GCCHK_RC_OK != result) {
                CheckError error = new CheckError(object, _cycle, _currentCheck, "Object", result, _cycle.nextErrorCount());
                _reporter.report(error);
                /* There are some error cases would not prevent further iteration */
                if (!((J9MODRON_GCCHK_RC_DEAD_OBJECT_NEXT_IS_NOT_HOLE == result) || (J9MODRON_GCCHK_RC_DEAD_OBJECT_NEXT_IS_NOT_IN_REGION == result) || (J9MODRON_GCCHK_RC_DEAD_OBJECT_NEXT_IS_POINTED_INSIDE == result))) {
                    _reporter.reportHeapWalkError(error, _lastHeapObject1, _lastHeapObject2, _lastHeapObject3);
                    return J9MODRON_SLOT_ITERATOR_UNRECOVERABLE_ERROR;
                }
            }
            return J9MODRON_SLOT_ITERATOR_OK;
        }
    } catch (CorruptDataException e) {
        // TODO : cde should be part of the error
        CheckError error = new CheckError(object, _cycle, _currentCheck, "Object ", J9MODRON_GCCHK_RC_CORRUPT_DATA_EXCEPTION, _cycle.nextErrorCount());
        _reporter.report(error);
        return J9MODRON_SLOT_ITERATOR_UNRECOVERABLE_ERROR;
    }
    try {
        // Prefetch this data to make CDE handling easy
        isIndexable = ObjectModel.isIndexable(object);
        clazz = J9ObjectHelper.clazz(object);
        result = checkJ9Object(object, regionDesc, _cycle.getCheckFlags());
    } catch (CorruptDataException cde) {
        // TODO : cde should be part of the error
        CheckError error = new CheckError(object, _cycle, _currentCheck, "Object ", J9MODRON_GCCHK_RC_CORRUPT_DATA_EXCEPTION, _cycle.nextErrorCount());
        _reporter.report(error);
        return J9MODRON_SLOT_ITERATOR_UNRECOVERABLE_ERROR;
    }
    if (J9MODRON_GCCHK_RC_OK != result) {
        String elementName = isIndexable ? "IObject " : "Object ";
        CheckError error = new CheckError(object, _cycle, _currentCheck, elementName, result, _cycle.nextErrorCount());
        _reporter.report(error);
        /* There are some error cases would not prevent further iteration */
        if (!(J9MODRON_GCCHK_RC_CLASS_IS_UNLOADED == result)) {
            _reporter.reportHeapWalkError(error, _lastHeapObject1, _lastHeapObject2, _lastHeapObject3);
            return J9MODRON_SLOT_ITERATOR_UNRECOVERABLE_ERROR;
        } else {
            return J9MODRON_SLOT_ITERATOR_OK;
        }
    }
    try {
        /* check Ownable Synchronizer Object consistency */
        if (needVerifyOwnableSynchronizerConsistency()) {
            if (J9Object.OBJECT_HEADER_SHAPE_MIXED == ObjectModel.getClassShape(clazz).intValue() && !J9ClassHelper.classFlags(clazz).bitAnd(J9AccClassOwnableSynchronizer).eq(0)) {
                if (ObjectAccessBarrier.isObjectInOwnableSynchronizerList(object).isNull()) {
                    CheckError error = new CheckError(object, _cycle, _currentCheck, "Object ", J9MODRON_GCCHK_OWNABLE_SYNCHRONIZER_OBJECT_IS_NOT_ATTACHED_TO_THE_LIST, _cycle.nextErrorCount());
                    _reporter.report(error);
                } else {
                    _ownableSynchronizerObjectCountOnHeap += 1;
                }
            }
        }
    } catch (CorruptDataException cde) {
        // TODO : cde should be part of the error
        CheckError error = new CheckError(object, _cycle, _currentCheck, "Object ", J9MODRON_GCCHK_RC_CORRUPT_DATA_EXCEPTION, _cycle.nextErrorCount());
        _reporter.report(error);
        return J9MODRON_SLOT_ITERATOR_UNRECOVERABLE_ERROR;
    }
    if (J9MODRON_GCCHK_RC_OK == result) {
        GCObjectIterator fieldIterator;
        GCObjectIterator addressIterator;
        try {
            fieldIterator = GCObjectIterator.fromJ9Object(object, true);
            addressIterator = GCObjectIterator.fromJ9Object(object, true);
        } catch (CorruptDataException e) {
            // TODO : cde should be part of the error
            CheckError error = new CheckError(object, _cycle, _currentCheck, "Object ", J9MODRON_GCCHK_RC_CORRUPT_DATA_EXCEPTION, _cycle.nextErrorCount());
            _reporter.report(error);
            return J9MODRON_SLOT_ITERATOR_UNRECOVERABLE_ERROR;
        }
        while (fieldIterator.hasNext()) {
            J9ObjectPointer field = fieldIterator.next();
            VoidPointer address = addressIterator.nextAddress();
            result = checkSlotObjectHeap(field, ObjectReferencePointer.cast(address), regionDesc, object);
            if (J9MODRON_SLOT_ITERATOR_OK != result) {
                break;
            }
        }
    }
    if (J9MODRON_GCCHK_RC_OK == result) {
        /* this heap object is OK. Record it in the cache in case we find a pointer to it soon */
        int cacheIndex = (int) (object.getAddress() % OBJECT_CACHE_SIZE);
        _checkedObjectCache[cacheIndex] = object;
    }
    return result;
}