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

Example 1 with MarkedObject

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

the class GCHeapMap method queryRange.

/**
 * Query the mark map to see what objects are marked within the specified range.
 * Return an array of MarkedObject records describing each entry found.
 * @param base Bottom of the range to query (inclusive)
 * @param top Top of the range to query (exclusive)
 * @return A MarkedObject[] containing the results
 * @throws CorruptDataException
 */
public MarkedObject[] queryRange(J9ObjectPointer base, J9ObjectPointer top) throws CorruptDataException {
    /* Naive implementation; should work but slow */
    ArrayList<MarkedObject> results = new ArrayList<MarkedObject>();
    if (base.lt(_heapBase)) {
        base = J9ObjectPointer.cast(_heapBase);
    }
    if (top.gt(_heapTop)) {
        top = J9ObjectPointer.cast(_heapTop);
    }
    if (base.gt(top)) {
        base = top;
    }
    J9ObjectPointer cursor = base;
    while (cursor.lt(top)) {
        UDATA[] indexAndMask = getSlotIndexAndMask(cursor);
        UDATAPointer slot = _heapMapBits.add(indexAndMask[0]);
        if (slot.at(0).bitAnd(indexAndMask[1]).gt(0)) {
            results.add(new MarkedObject(cursor, slot));
        }
        cursor = cursor.addOffset(getObjectGrain());
    }
    return results.toArray(new MarkedObject[results.size()]);
}

Example 2 with MarkedObject

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

the class GCMarkMapStandard method queryRange.

@Override
public MarkedObject[] queryRange(J9ObjectPointer base, J9ObjectPointer top) throws CorruptDataException {
    /* Naive implementation; should work but slow -- ever more than the super.
		  * Add handling for compacted records in the mark map. */
    ArrayList<MarkedObject> results = new ArrayList<MarkedObject>();
    if (base.lt(_heapBase)) {
        base = J9ObjectPointer.cast(_heapBase);
    }
    if (top.gt(_heapTop)) {
        top = J9ObjectPointer.cast(_heapTop);
    }
    if (base.gt(top)) {
        base = top;
    }
    J9ObjectPointer cursor = base;
    while (cursor.lt(top)) {
        UDATA heapBaseOffset = UDATA.cast(cursor).sub(UDATA.cast(_heapBase));
        // pairs of UDATA, so *2
        UDATA pageIndex = heapBaseOffset.div(MM_CompactScheme.sizeof_page).mult(2);
        UDATA compactTableEntry_addr = _heapMapBits.at(pageIndex);
        UDATA compactTableEntry_bits = _heapMapBits.at(pageIndex.add(1));
        // Horribly inefficient -- recomputing relocations every single time!
        if (compactTableEntry_addr.allBitsIn(3)) {
            // Object has been compacted -- assuming that the pointer was the pre-compacted one
            J9ObjectPointer newObject = J9ObjectPointer.cast(compactTableEntry_addr.bitAnd(~3));
            UDATA bits = compactTableEntry_bits;
            UDATA offset = heapBaseOffset.mod(MM_CompactScheme.sizeof_page).div(2 * MM_HeapMap.J9MODRON_HEAP_SLOTS_PER_HEAPMAP_BIT * UDATA.SIZEOF);
            UDATA bitMask = new UDATA(1).leftShift(offset);
            if (bits.bitAnd(bitMask).eq(bitMask)) {
                long mask = 1;
                int ordinal = 0;
                for (int i = offset.intValue(); i > 0; i--) {
                    if (bits.allBitsIn(mask)) {
                        ordinal += 1;
                    }
                    mask <<= 1;
                }
                for (int i = 0; i < ordinal; i++) {
                    UDATA objectSize = ObjectModel.getConsumedSizeInBytesWithHeader(newObject);
                    newObject = newObject.addOffset(objectSize);
                }
                results.add(new MarkedObject(cursor, _heapMapBits.add(pageIndex), newObject));
            }
            cursor = cursor.addOffset(getObjectGrain() * 2);
        } else {
            /* Same as super */
            UDATA[] indexAndMask = getSlotIndexAndMask(cursor);
            UDATAPointer slot = _heapMapBits.add(indexAndMask[0]);
            if (slot.at(0).bitAnd(indexAndMask[1]).gt(0)) {
                results.add(new MarkedObject(cursor, slot));
            }
            cursor = cursor.addOffset(getObjectGrain());
        }
    }
    return results.toArray(new MarkedObject[results.size()]);
}

Example 3 with MarkedObject

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

the class MarkMapCommand method isMarked.

protected void isMarked(String[] args, Context context, PrintStream out) throws DDRInteractiveCommandException {
    try {
        long address = CommandUtils.parsePointer(args[1], J9BuildFlags.env_data64);
        J9ObjectPointer object = J9ObjectPointer.cast(address);
        MarkedObject result = markMap.queryObject(object);
        if (result != null) {
            if (result.wasRelocated()) {
                out.format("Object %s is marked and relocated to %s\n", result.object.getHexAddress(), result.relocatedObject.getHexAddress());
            } else {
                out.format("Object %s is marked\n", result.object.getHexAddress());
            }
        } else {
            out.format("Object %s is not marked\n", object.getHexAddress());
        }
    } catch (CorruptDataException e) {
        throw new DDRInteractiveCommandException(e);
    }
}

Example 4 with MarkedObject

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

the class MarkMapCommand method findSource.

protected void findSource(String[] args, Context context, PrintStream out) throws DDRInteractiveCommandException {
    try {
        long address = CommandUtils.parsePointer(args[1], J9BuildFlags.env_data64);
        J9ObjectPointer object = J9ObjectPointer.cast(address);
        J9ObjectPointer scanPtr = J9ObjectPointer.cast(markMap.getHeapBase());
        J9ObjectPointer heapTop = J9ObjectPointer.cast(markMap.getHeapTop());
        if (object.gte(scanPtr) && object.lt(heapTop)) {
            int count = 0;
            while (scanPtr.lt(heapTop)) {
                J9ObjectPointer base = scanPtr;
                J9ObjectPointer top = base.addOffset(markMap.getPageSize(scanPtr));
                MarkedObject[] results = markMap.queryRange(base, top);
                for (int i = 0; i < results.length; i++) {
                    MarkedObject result = results[i];
                    if (result.wasRelocated()) {
                        if (result.relocatedObject.eq(object)) {
                            // A match!
                            out.format("Object %s was relocated to %s\n", result.object.getHexAddress(), result.relocatedObject.getHexAddress());
                            count += 1;
                        }
                    }
                }
                scanPtr = top;
            }
            if (count > 0) {
                out.format("%1 relocation candidates found\n", count);
            } else {
                out.format("No relocation candidates found\n");
            }
        } else {
            out.format("Object %s is not in the heap\n", object.getHexAddress());
        }
    } catch (CorruptDataException e) {
        throw new DDRInteractiveCommandException(e);
    }
}

Example 5 with MarkedObject

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

the class MarkMapCommand method near.

protected void near(String[] args, Context context, PrintStream out) throws DDRInteractiveCommandException {
    try {
        long address = CommandUtils.parsePointer(args[1], J9BuildFlags.env_data64);
        J9ObjectPointer object = J9ObjectPointer.cast(address);
        J9ObjectPointer base = object.untag(markMap.getPageSize(object) - 1);
        J9ObjectPointer top = base.addOffset(markMap.getPageSize(object));
        MarkedObject[] results = markMap.queryRange(base, top);
        reportResults(base, top, results, out);
    } catch (CorruptDataException e) {
        throw new DDRInteractiveCommandException(e);
    }
}