Examples with J9ClassPointer com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer used on opensource projects

Example 1 with J9ClassPointer

use of com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer in project openj9 by eclipse.

the class J9ObjectFieldOffsetIterator_V1 method calculateInstanceSize.

private void calculateInstanceSize(J9ROMClassPointer romClass, J9ClassPointer superClazz) throws CorruptDataException {
    lockwordNeeded = NO_LOCKWORD_NEEDED;
    /* if we only care about statics we can skip all work related to instance size calculations */
    if (!walkFlags.anyBitsIn(J9VM_FIELD_OFFSET_WALK_INCLUDE_INSTANCE | J9VM_FIELD_OFFSET_WALK_CALCULATE_INSTANCE_SIZE)) {
        return;
    }
    ObjectFieldInfo fieldInfo = new ObjectFieldInfo(romClass);
    /*
		 * Step 1: Calculate the size of the superclass and backfill offset.
		 * Inherit the instance size and backfillOffset from the superclass.
		 */
    if (superClazz.notNull()) {
        /*
			 * Note that in the J9Class, we do not store -1 to indicate no back fill,
			 * we store the total instance size (including the header) instead.
			 */
        fieldInfo.setSuperclassFieldsSize(superClazz.totalInstanceSize().intValue());
        if (!superClazz.backfillOffset().eq(superClazz.totalInstanceSize().add(J9Object.SIZEOF))) {
            fieldInfo.setSuperclassBackfillOffset(superClazz.backfillOffset().sub(J9Object.SIZEOF).intValue());
        }
    } else {
        fieldInfo.setSuperclassFieldsSize(0);
    }
    lockwordNeeded = checkLockwordNeeded(romClass, superClazz, instanceClass);
    /*
		 * remove the lockword from Object (if there is one) only if we don't need a lockword or we do need one
		 * and we are not re-using the one from Object which we can tell because lockwordNeeded is LOCKWORD_NEEDED as
		 * opposed to the value of the existing offset.
		 */
    if ((LOCKWORD_NEEDED.equals(lockwordNeeded)) || (NO_LOCKWORD_NEEDED.equals(lockwordNeeded))) {
        if (superClazz.notNull() && !superClazz.lockOffset().eq(new UDATA(-1)) && J9ClassHelper.classDepth(superClazz).isZero()) {
            int newSuperSize = fieldInfo.getSuperclassFieldsSize() - LOCKWORD_SIZE;
            /* this may  have been rounded to 8 bytes so also get rid of the padding */
            if (fieldInfo.isSuperclassBackfillSlotAvailable()) {
                /* j.l.Object was not end aligned */
                newSuperSize -= BACKFILL_SIZE;
                fieldInfo.setSuperclassBackfillOffset(NO_BACKFILL_AVAILABLE);
            }
            fieldInfo.setSuperclassFieldsSize(newSuperSize);
        }
    }
    /*
		 * Step 2: Determine which extra hidden fields we need and prepend them to the list of hidden fields.
		 */
    LinkedList<HiddenInstanceField> extraHiddenFields = copyHiddenInstanceFieldsList(vm);
    finalizeLinkOffset = new UDATA(0);
    if (!superClazz.isNull() && !superClazz.finalizeLinkOffset().isZero()) {
        /* Superclass is finalizeable */
        finalizeLinkOffset = superClazz.finalizeLinkOffset();
    } else {
        /* Superclass is not finalizeable */
        if (J9ROMClassHelper.finalizeNeeded(romClass)) {
            extraHiddenFields.addFirst(new HiddenInstanceField(vm.hiddenFinalizeLinkFieldShape()));
        }
    }
    lockOffset = new UDATA(lockwordNeeded);
    if (lockOffset.eq(LOCKWORD_NEEDED)) {
        extraHiddenFields.addFirst(new HiddenInstanceField(vm.hiddenLockwordFieldShape()));
    }
    /*
		 * Step 3: Calculate the number of various categories of fields: single word primitive, double word primitive, and object references.
		 * Iterate over fields to count instance fields by size.
		 */
    fieldInfo.countInstanceFields();
    fieldInfo.countAndCopyHiddenFields(extraHiddenFields, hiddenInstanceFieldList);
    new UDATA(fieldInfo.calculateTotalFieldsSizeAndBackfill());
    firstDoubleOffset = new UDATA(fieldInfo.calculateFieldDataStart());
    firstObjectOffset = new UDATA(fieldInfo.addDoublesArea(firstDoubleOffset.intValue()));
    firstSingleOffset = new UDATA(fieldInfo.addObjectsArea(firstObjectOffset.intValue()));
    if (fieldInfo.isMyBackfillSlotAvailable() && fieldInfo.isBackfillSuitableFieldAvailable()) {
        if (fieldInfo.isBackfillSuitableInstanceSingleAvailable()) {
            walkFlags = walkFlags.bitOr(J9VM_FIELD_OFFSET_WALK_BACKFILL_SINGLE_FIELD);
        } else if (fieldInfo.isBackfillSuitableInstanceObjectAvailable()) {
            walkFlags = walkFlags.bitOr(J9VM_FIELD_OFFSET_WALK_BACKFILL_OBJECT_FIELD);
        }
    }
    /*
		 * Calculate offsets (from the object header) for hidden fields.  Hidden fields follow immediately the instance fields of the same type.
		 * Give instance fields priority for backfill slots.
		 * Note that the hidden fields remember their offsets, so this need be done once only.
		 */
    if (!hiddenInstanceFieldList.isEmpty()) {
        UDATA hiddenSingleOffset = firstSingleOffset.add(J9Object.SIZEOF + (fieldInfo.getNonBackfilledInstanceSingleCount() * U32.SIZEOF));
        UDATA hiddenDoubleOffset = firstDoubleOffset.add(J9Object.SIZEOF + (fieldInfo.getInstanceDoubleCount() * U64.SIZEOF));
        UDATA hiddenObjectOffset = firstObjectOffset.add(J9Object.SIZEOF + (fieldInfo.getNonBackfilledInstanceObjectCount() * fj9object_t_SizeOf));
        boolean useBackfillForObject = false;
        boolean useBackfillForSingle = false;
        if (fieldInfo.isMyBackfillSlotAvailable() && !walkFlags.anyBitsIn(J9VM_FIELD_OFFSET_WALK_BACKFILL_OBJECT_FIELD | J9VM_FIELD_OFFSET_WALK_BACKFILL_SINGLE_FIELD)) {
            /* There are no backfill-suitable instance fields, so let the hidden fields use the backfill slot */
            if (fieldInfo.isBackfillSuitableSingleAvailable()) {
                useBackfillForSingle = true;
            } else if (fieldInfo.isBackfillSuitableObjectAvailable()) {
                useBackfillForObject = true;
            }
        }
        for (HiddenInstanceField hiddenField : hiddenInstanceFieldList) {
            U32 modifiers = hiddenField.shape().modifiers();
            if (modifiers.allBitsIn(J9FieldFlagObject)) {
                if (useBackfillForObject) {
                    hiddenField.setFieldOffset(fieldInfo.getMyBackfillOffsetForHiddenField());
                    useBackfillForObject = false;
                } else {
                    hiddenField.setFieldOffset(hiddenObjectOffset);
                    hiddenObjectOffset = hiddenObjectOffset.add(fj9object_t_SizeOf);
                }
            } else if (modifiers.allBitsIn(J9FieldSizeDouble)) {
                hiddenField.setFieldOffset(hiddenDoubleOffset);
                hiddenDoubleOffset = hiddenDoubleOffset.add(U64.SIZEOF);
            } else {
                if (useBackfillForSingle) {
                    hiddenField.setFieldOffset(fieldInfo.getMyBackfillOffsetForHiddenField());
                    useBackfillForSingle = false;
                } else {
                    hiddenField.setFieldOffset(hiddenSingleOffset);
                    hiddenSingleOffset = hiddenSingleOffset.add(U32.SIZEOF);
                }
            }
        }
    }
    backfillOffsetToUse = new IDATA(fieldInfo.getMyBackfillOffset());
/* backfill offset for this class's fields */
}

Example 2 with J9ClassPointer

use of com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer in project openj9 by eclipse.

the class VMConstantPool method getFieldOffset.

/**
 * Get a field offset from the constant pool.
 * @param index A J9VmconstantpoolConstants index into the constant pool.  Must be for a static or instance field reference.
 * @return Either the offset to the object, or null if the field's class is not resolved in the constant pool.
 * @throws CorruptDataException If the field cannot be found in the related class or the CP index is not a field reference.
 */
public static J9ObjectFieldOffset getFieldOffset(long index) throws CorruptDataException {
    if (_constantPool.length <= index || 0 > index) {
        throw new IndexOutOfBoundsException("Index outside of constant pool bounds");
    }
    int cpIndex = (int) index;
    long shapeDesc = ConstantPoolHelpers.J9_CP_TYPE(_cpShapeDescription, cpIndex);
    if (J9CPTYPE_FIELD != shapeDesc) {
        throw new CorruptDataException("VMConstantPool[" + index + "] CP_TYPE is not J9CPTYPE_FIELD");
    }
    /* The offset of the field, to be returned */
    J9ObjectFieldOffset offset = null;
    if (null != _constantPool[cpIndex]) {
        offset = (J9ObjectFieldOffset) _constantPool[cpIndex];
    } else {
        J9ROMFieldRefPointer romRef = J9ROMFieldRefPointer.cast(_romCPStart.add(cpIndex));
        J9ClassPointer refClass = getClass(romRef.classRefCPIndex().longValue());
        J9ClassPointer currentClass = refClass;
        if (currentClass.notNull()) {
            /* If the current class is J9ClassPointer.NULL, return null as the field offset */
            /* Resolve the fieldname, starting from the current class,
				 * and working up the class hierarchy towards the super classes. This should
				 * properly handle shadowed fields.
				 */
            String fieldName = J9UTF8Helper.stringValue(romRef.nameAndSignature().name());
            String signature = J9UTF8Helper.stringValue(romRef.nameAndSignature().signature());
            while (currentClass.notNull() && (null == offset)) {
                Iterator<J9ObjectFieldOffset> fields = J9ClassHelper.getFieldOffsets(currentClass);
                while (fields.hasNext()) {
                    J9ObjectFieldOffset field = fields.next();
                    if (field.getName().equals(fieldName) && field.getSignature().equals(signature)) {
                        offset = field;
                        break;
                    }
                }
                currentClass = J9ClassHelper.superclass(currentClass);
            }
            if (null == offset) {
                /* The field should exist in the class it points to, unless the constant pool is corrupt or wrong */
                throw new CorruptDataException("VMConstantPool[" + index + "] field not found: " + J9ClassHelper.getName(refClass) + "." + fieldName + " " + signature);
            } else {
                _constantPool[cpIndex] = offset;
            }
        }
    }
    return offset;
}

Example 3 with J9ClassPointer

use of com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer in project openj9 by eclipse.

the class VMConstantPool method getClass.

/**
 * Get a class from the constant pool.
 * @param index A J9VmconstantpoolConstants index into the constant pool.  Must be for a class reference.
 * @return Either the loaded class, or if its not in the constant pool, J9ClassPointer.NULL.
 * @throws CorruptDataException If the CPShape of the index is not a class.
 */
public static J9ClassPointer getClass(long index) throws CorruptDataException {
    if (_constantPool.length <= index || 0 > index) {
        throw new IndexOutOfBoundsException("Index outside of constant pool bounds");
    }
    int cpIndex = (int) index;
    long shapeDesc = ConstantPoolHelpers.J9_CP_TYPE(_cpShapeDescription, cpIndex);
    if (J9CPTYPE_CLASS != shapeDesc) {
        throw new CorruptDataException("VMConstantPool[" + index + "] CP_TYPE is not J9CPTYPE_CLASS");
    }
    J9ClassPointer classPointer = null;
    if (null != _constantPool[cpIndex]) {
        classPointer = (J9ClassPointer) _constantPool[cpIndex];
    } else {
        J9RAMConstantPoolItemPointer ramEntry = _ramCPStart.add(index);
        classPointer = J9RAMClassRefPointer.cast(ramEntry).value();
        _constantPool[cpIndex] = classPointer;
    }
    return classPointer;
}

Example 4 with J9ClassPointer

use of com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer in project openj9 by eclipse.

the class GCConstantPoolSlotIterator method initializeSlots_V1.

protected void initializeSlots_V1(J9ClassPointer clazz, boolean returnClassSlots, boolean returnObjectSlots) throws CorruptDataException {
    U32Pointer cpDescriptionSlots = clazz.romClass().cpShapeDescription();
    PointerPointer cpEntry = PointerPointer.cast(clazz.ramConstantPool());
    long cpDescription = 0;
    long cpEntryCount = clazz.romClass().ramConstantPoolCount().longValue();
    long cpDescriptionIndex = 0;
    ArrayList<AbstractPointer> slots = new ArrayList<AbstractPointer>();
    ArrayList<VoidPointer> addresses = new ArrayList<VoidPointer>();
    while (cpEntryCount > 0) {
        if (0 == cpDescriptionIndex) {
            // Load a new description word
            cpDescription = cpDescriptionSlots.at(0).longValue();
            cpDescriptionSlots = cpDescriptionSlots.add(1);
            cpDescriptionIndex = J9_CP_DESCRIPTIONS_PER_U32;
        }
        long slotType = cpDescription & J9_CP_DESCRIPTION_MASK;
        if ((slotType == J9CPTYPE_STRING) || (slotType == J9CPTYPE_ANNOTATION_UTF8)) {
            if (returnObjectSlots) {
                J9RAMStringRefPointer ref = J9RAMStringRefPointer.cast(cpEntry);
                J9ObjectPointer slot = ref.stringObject();
                if (slot.notNull()) {
                    slots.add(slot);
                    addresses.add(VoidPointer.cast(ref.stringObjectEA()));
                }
            }
        } else if (slotType == J9CPTYPE_METHOD_TYPE) {
            if (returnObjectSlots) {
                J9RAMMethodTypeRefPointer ref = J9RAMMethodTypeRefPointer.cast(cpEntry);
                J9ObjectPointer slot = ref.type();
                if (slot.notNull()) {
                    slots.add(slot);
                    addresses.add(VoidPointer.cast(ref.typeEA()));
                }
            }
        } else if (slotType == J9CPTYPE_METHODHANDLE) {
            if (returnObjectSlots) {
                J9RAMMethodHandleRefPointer ref = J9RAMMethodHandleRefPointer.cast(cpEntry);
                J9ObjectPointer slot = ref.methodHandle();
                if (slot.notNull()) {
                    slots.add(slot);
                    addresses.add(VoidPointer.cast(ref.methodHandleEA()));
                }
            }
        } else if (slotType == J9CPTYPE_CLASS) {
            if (returnClassSlots) {
                J9RAMClassRefPointer ref = J9RAMClassRefPointer.cast(cpEntry);
                J9ClassPointer slot = ref.value();
                if (slot.notNull()) {
                    slots.add(slot);
                    addresses.add(VoidPointer.cast(ref.valueEA()));
                }
            }
        }
        cpEntry = cpEntry.addOffset(J9RAMConstantPoolItem.SIZEOF);
        cpEntryCount -= 1;
        cpDescription >>= J9_CP_BITS_PER_DESCRIPTION;
        cpDescriptionIndex -= 1;
    }
    slotIterator = slots.iterator();
    addressIterator = addresses.iterator();
}

Example 5 with J9ClassPointer

use of com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer in project openj9 by eclipse.

the class GCClassLoaderSegmentClassesIterator method next.

public J9ClassPointer next() {
    if (!hasNext()) {
        throw new NoSuchElementException("There are no more items available through this iterator");
    }
    J9ClassPointer next = _nextClass;
    advanceIterator();
    return next;
}