Examples with J9ObjectFieldOffset com.ibm.j9ddr.vm29.j9.J9ObjectFieldOffset used on opensource projects

Example 6 with J9ObjectFieldOffset

use of com.ibm.j9ddr.vm29.j9.J9ObjectFieldOffset in project openj9 by eclipse.

the class JavaLangClassLoaderHelper method getParent.

public static J9ObjectPointer getParent(J9ObjectPointer loader) throws CorruptDataException {
    if (loader.isNull()) {
        return J9ObjectPointer.NULL;
    }
    if (parentOffset == null) {
        // Iterate through all the fields of Ljava/lang/ClassLoader; until you find "parent"
        J9JavaVMPointer vm = J9RASHelper.getVM(DataType.getJ9RASPointer());
        J9ClassPointer javaLangClassLoader = J9ClassLoaderHelper.findClass(vm.systemClassLoader(), "Ljava/lang/ClassLoader;");
        Iterator<J9ObjectFieldOffset> fieldIterator = J9ClassHelper.getFieldOffsets(javaLangClassLoader);
        while (fieldIterator.hasNext()) {
            Object nextField = fieldIterator.next();
            if (nextField instanceof J9ObjectFieldOffset) {
                J9ObjectFieldOffset offset = (J9ObjectFieldOffset) nextField;
                if ("parent".equals(offset.getName())) {
                    parentOffset = offset;
                    break;
                }
            }
        }
    }
    if (parentOffset != null) {
        return J9ObjectHelper.getObjectField(loader, parentOffset);
    } else {
        throw new CorruptDataException("Unable to find field offset for the 'parent' field");
    }
}

Example 7 with J9ObjectFieldOffset

use of com.ibm.j9ddr.vm29.j9.J9ObjectFieldOffset in project openj9 by eclipse.

the class J9ObjectHelper method getFieldOffset.

private static J9ObjectFieldOffset getFieldOffset(J9ObjectPointer objPointer, String name, String signature) throws CorruptDataException {
    J9ObjectFieldOffset result = J9ClassHelper.checkFieldOffsetCache(J9ObjectHelper.clazz(objPointer), name, signature);
    if (result == null) {
        result = readFieldOffset(objPointer, name, signature);
        J9ClassHelper.setFieldOffsetCache(J9ObjectHelper.clazz(objPointer), result, name, signature);
    }
    return result;
}

Example 8 with J9ObjectFieldOffset

use of com.ibm.j9ddr.vm29.j9.J9ObjectFieldOffset in project openj9 by eclipse.

the class J9ObjectHelper method readFieldOffset.

// FIXME: Probably want to cache the entire class hierarchy the 1st time through for any field
private static J9ObjectFieldOffset readFieldOffset(J9ObjectPointer objPointer, String name, String signature) throws CorruptDataException {
    J9ClassPointer currentClass = J9ObjectHelper.clazz(objPointer);
    while (currentClass.notNull()) {
        Iterator<J9ObjectFieldOffset> fields = J9ClassHelper.getFieldOffsets(currentClass);
        while (fields.hasNext()) {
            J9ObjectFieldOffset field = (J9ObjectFieldOffset) fields.next();
            if (field.getName().equals(name) && field.getSignature().equals(signature)) {
                return field;
            }
        }
        currentClass = J9ClassHelper.superclass(currentClass);
    }
    throw new NoSuchElementException(String.format("No field named %s with signature %s in %s", name, signature, J9ObjectHelper.getClassName(objPointer)));
}

Example 9 with J9ObjectFieldOffset

use of com.ibm.j9ddr.vm29.j9.J9ObjectFieldOffset in project openj9 by eclipse.

the class J9ClassShapeCommand method run.

public void run(String command, String[] args, Context context, PrintStream out) throws DDRInteractiveCommandException {
    if (args.length != 1) {
        CommandUtils.dbgPrint(out, "Usage: !j9classshape <classAddress>\n");
        return;
    }
    try {
        J9JavaVMPointer vm = J9RASHelper.getVM(DataType.getJ9RASPointer());
        J9ClassPointer instanceClass = J9ClassPointer.NULL;
        String classSelector = args[0];
        if (classSelector.matches("\\p{Digit}.*")) {
            /* addresses start with a decimal digit, possibly the '0' in "0x" */
            instanceClass = J9ClassPointer.cast(CommandUtils.parsePointer(classSelector, J9BuildFlags.env_data64));
        } else {
            J9ClassPointer[] candidates = findClassByName(vm, classSelector);
            if (candidates.length == 0) {
                CommandUtils.dbgPrint(out, "No classes matching \"" + classSelector + "\" found\n");
                return;
            } else if (candidates.length > 1) {
                CommandUtils.dbgPrint(out, "Multiple classes matching \"" + classSelector + "\" found\n");
                return;
            } else {
                instanceClass = candidates[0];
                String javaName = J9ClassHelper.getJavaName(instanceClass);
                String hexString = instanceClass.getHexAddress();
                CommandUtils.dbgPrint(out, String.format("!j9class %1$s\n", hexString));
            }
        }
        J9ClassPointer previousSuperclass = J9ClassPointer.NULL;
        String className = J9ClassHelper.getName(instanceClass);
        J9VMThreadPointer mainThread = vm.mainThread();
        boolean lockwordPrinted = true;
        if (J9BuildFlags.thr_lockNursery) {
            lockwordPrinted = false;
        }
        CommandUtils.dbgPrint(out, "Instance fields in %s:\n", className);
        CommandUtils.dbgPrint(out, "\noffset     name\tsignature\t(declaring class)\n");
        if (mainThread.isNull()) {
            /* we cannot print the instance fields without this */
            return;
        }
        long depth = J9ClassHelper.classDepth(instanceClass).longValue();
        for (long superclassIndex = 0; superclassIndex <= depth; superclassIndex++) {
            J9ClassPointer superclass;
            if (superclassIndex == depth) {
                superclass = instanceClass;
            } else {
                superclass = J9ClassPointer.cast(instanceClass.superclasses().at(superclassIndex));
            }
            U32 flags = new U32(J9VM_FIELD_OFFSET_WALK_INCLUDE_INSTANCE | J9VM_FIELD_OFFSET_WALK_INCLUDE_HIDDEN);
            Iterator<J9ObjectFieldOffset> iterator = J9ObjectFieldOffsetIterator.J9ObjectFieldOffsetIteratorFor(superclass.romClass(), instanceClass, previousSuperclass, flags);
            while (iterator.hasNext()) {
                J9ObjectFieldOffset result = (J9ObjectFieldOffset) iterator.next();
                boolean printField = true;
                boolean isHiddenField = result.isHidden();
                if (J9BuildFlags.thr_lockNursery) {
                    boolean isLockword = (isHiddenField && (result.getOffsetOrAddress().add(J9Object.SIZEOF).eq(superclass.lockOffset())));
                    if (isLockword) {
                        /*
							 * Print the lockword field if it is indeed the
							 * lockword for this instanceClass and we haven't
							 * printed it yet.
							 */
                        printField = !lockwordPrinted && instanceClass.lockOffset().eq(superclass.lockOffset());
                        if (printField) {
                            lockwordPrinted = true;
                        }
                    }
                }
                if (printField) {
                    printShapeField(out, superclass, result.getField(), result.getOffsetOrAddress(), isHiddenField);
                }
            }
            previousSuperclass = superclass;
        }
        CommandUtils.dbgPrint(out, "\nTotal instance size: %d\n", instanceClass.totalInstanceSize().longValue());
    } catch (CorruptDataException e) {
        throw new DDRInteractiveCommandException(e);
    }
}

Example 10 with J9ObjectFieldOffset

use of com.ibm.j9ddr.vm29.j9.J9ObjectFieldOffset in project openj9 by eclipse.

the class CheckEngine method checkClassStatics.

private int checkClassStatics(J9ClassPointer clazz) {
    int result = J9MODRON_GCCHK_RC_OK;
    try {
        boolean validationRequired = true;
        if (J9ClassHelper.isSwappedOut(clazz)) {
            /* if class has been hot swapped (J9AccClassHotSwappedOut bit is set) in Fast HCR,
				 * the ramStatics of the existing class may be reused.  The J9ClassReusedStatics
				 * bit in J9Class->extendedClassFlags will be set if that's the case.
				 * In Extended HCR mode ramStatics might be not NULL and must be valid
				 * NOTE: If class is hot swapped and the value in ramStatics is NULL it is valid 
				 * to have the correspondent ROM Class value in objectStaticCount field greater then 0
				 */
            if (J9ClassHelper.isArrayClass(clazz)) {
                /* j9arrayclass should not be hot swapped */
                result = J9MODRON_GCCHK_RC_CLASS_HOT_SWAPPED_FOR_ARRAY;
                CheckError error = new CheckError(clazz, _cycle, _currentCheck, "Class ", result, _cycle.nextErrorCount());
                _reporter.report(error);
                return result;
            }
            if (J9ClassHelper.areExtensionsEnabled()) {
                /* This is Extended HSR mode so hot swapped class might have NULL in ramStatics field */
                if (clazz.ramStatics().isNull()) {
                    validationRequired = false;
                }
            }
            try {
                /* This case can also occur when running -Xint with extensions enabled */
                if (J9ClassHelper.extendedClassFlags(clazz).allBitsIn(J9JavaClassFlags.J9ClassReusedStatics)) {
                    validationRequired = false;
                }
            } catch (NoSuchFieldError e) {
            /* Flag must be missing from the core. */
            }
        }
        if (validationRequired) {
            // J9ClassLoaderPointer classLoader = clazz.classLoader();
            J9ROMClassPointer romClazz = clazz.romClass();
            UDATA numberOfReferences = new UDATA(0);
            PointerPointer sectionStart = PointerPointer.NULL;
            PointerPointer sectionEnd = PointerPointer.NULL;
            /*
				 * Note: we have no special recognition for J9ArrayClass here
				 * J9ArrayClass does not have a ramStatics field but something else at this place
				 * so direct check (NULL != clazz->ramStatics) would not be correct,
				 * however romClazz->objectStaticCount must be 0 for this case
				 */
            if (!romClazz.objectStaticCount().eq(0)) {
                sectionStart = PointerPointer.cast(clazz.ramStatics());
                sectionEnd = sectionStart.add(romClazz.objectStaticCount());
            }
            /* Iterate all fields of ROM Class looking to statics fields pointed to java objects */
            Iterator<J9ObjectFieldOffset> objectFieldOffsetIterator = J9ObjectFieldOffsetIterator.J9ObjectFieldOffsetIteratorFor(clazz, J9ClassHelper.superclass(clazz), new U32(J9VM_FIELD_OFFSET_WALK_INCLUDE_STATIC | J9VM_FIELD_OFFSET_WALK_ONLY_OBJECT_SLOTS));
            while (objectFieldOffsetIterator.hasNext()) {
                J9ObjectFieldOffset fieldOffset = objectFieldOffsetIterator.next();
                // J9ROMFieldShapePointer field = fieldOffset.getField();
                numberOfReferences = numberOfReferences.add(1);
                /* get address of next field */
                PointerPointer address = sectionStart.addOffset(fieldOffset.getOffsetOrAddress());
                /* an address must be in gc scan range */
                if (!(address.gte(sectionStart) && address.lt(sectionEnd))) {
                    result = J9MODRON_GCCHK_RC_CLASS_STATICS_REFERENCE_IS_NOT_IN_SCANNING_RANGE;
                    CheckError error = new CheckError(clazz, address, _cycle, _currentCheck, "Class ", result, _cycle.nextErrorCount());
                    _reporter.report(error);
                }
            /* check only if we have an object */
            // TODO kmt : can't easily implement this part of the check
            // J9Class* classToCast = vm->internalVMFunctions->internalFindClassUTF8(currentThread, toSearchString, toSearchLength, classLoader, J9_FINDCLASS_FLAG_EXISTING_ONLY);
            // if ((NULL == classToCast) || (0 == instanceOfOrCheckCast(J9GC_J9OBJECT_CLAZZ(*address), classToCast))) {
            // The issue is that we can't simply call "internalFindClassUTF8" in DDR.
            // We could guess at the behaviour of the ClassLoader, but that makes
            // distingushing a real problem from a weird ClassLoader delegation
            // model difficult.
            }
            if (!numberOfReferences.eq(romClazz.objectStaticCount())) {
                result = J9MODRON_GCCHK_RC_CLASS_STATICS_WRONG_NUMBER_OF_REFERENCES;
                CheckError error = new CheckError(clazz, _cycle, _currentCheck, "Class ", result, _cycle.nextErrorCount());
                _reporter.report(error);
            }
        }
    } catch (CorruptDataException e) {
        // TODO : cde should be part of the error
        CheckError error = new CheckError(clazz, _cycle, _currentCheck, "Class ", J9MODRON_GCCHK_RC_CORRUPT_DATA_EXCEPTION, _cycle.nextErrorCount());
        _reporter.report(error);
    }
    return result;
}