--- a/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/gc/shared/CollectedHeap.java Tue Feb 19 10:02:42 2019 +0100
+++ b/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/gc/shared/CollectedHeap.java Tue Feb 19 10:02:54 2019 +0100
@@ -31,6 +31,8 @@
import sun.jvm.hotspot.memory.*;
import sun.jvm.hotspot.runtime.*;
import sun.jvm.hotspot.types.*;
+import sun.jvm.hotspot.utilities.BitMapInterface;
+import sun.jvm.hotspot.utilities.BitMapSegmented;
public abstract class CollectedHeap extends VMObject {
private static long reservedFieldOffset;
@@ -93,4 +95,8 @@
tty.println("unknown subtype of CollectedHeap @ " + getAddress() + " (" +
mr.start() + "," + mr.end() + ")");
}
+
+ public BitMapInterface createBitMap(long bits) {
+ return new BitMapSegmented(bits);
+ }
}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/utilities/BitMapInterface.java Tue Feb 19 10:02:54 2019 +0100
@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+package sun.jvm.hotspot.utilities;
+
+/** Minimal bitmap interface to support bitmaps spanning more than Integer.MAX_VALUE bits. */
+public interface BitMapInterface {
+ public boolean at(long offset);
+ public void atPut(long offset, boolean value);
+ public void clear();
+}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/utilities/BitMapSegmented.java Tue Feb 19 10:02:54 2019 +0100
@@ -0,0 +1,99 @@
+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+package sun.jvm.hotspot.utilities;
+
+/** A BitMap implementing the BitMapInterface. */
+public class BitMapSegmented implements BitMapInterface {
+ private static final int SegmentSizeBits = 30;
+ private static final int SegmentSize = 1 << (SegmentSizeBits - 1);
+
+ public BitMapSegmented(long sizeInBits) {
+ this.size = sizeInBits;
+
+ if (sizeInBits == 0) {
+ segmentBitMaps = new BitMap[0];
+ return;
+ }
+
+ int lastSegmentSize = (int)(sizeInBits % SegmentSize);
+
+ int segments = segmentIndex(sizeInBits - 1) + 1;
+ int completeSegments = segments - ((lastSegmentSize != 0) ? 1 : 0);
+
+ segmentBitMaps = new BitMap[segments];
+
+ for (int i = 0; i < completeSegments; i++) {
+ segmentBitMaps[i] = new BitMap(SegmentSize);
+ }
+
+ if (lastSegmentSize != 0) {
+ segmentBitMaps[completeSegments] = new BitMap(lastSegmentSize);
+ }
+ }
+
+ public long size() {
+ return size;
+ }
+
+ // Accessors
+ public boolean at(long offset) {
+ assert offset < size;
+
+ int segmentIndex = segmentIndex(offset);
+ int segmentOffset = segmentOffset(offset);
+ return segmentBitMaps[segmentIndex].at(segmentOffset);
+ }
+
+ public void atPut(long offset, boolean value) {
+ assert offset < size;
+
+ int segmentIndex = segmentIndex(offset);
+ int segmentOffset = segmentOffset(offset);
+ segmentBitMaps[segmentIndex].atPut(segmentOffset, value);
+ }
+
+ public void clear() {
+ for (BitMap map : segmentBitMaps) {
+ map.clear();
+ }
+ }
+
+ //----------------------------------------------------------------------
+ // Internals only below this point
+ //
+ private final long size; // in bits
+ private final BitMap[] segmentBitMaps;
+
+ private int segmentIndex(long offset) {
+ long longIndex = offset / SegmentSize;
+
+ assert longIndex < Integer.MAX_VALUE;
+ return (int)longIndex;
+ }
+
+ private int segmentOffset(long offset) {
+ return (int)(offset % SegmentSize);
+ }
+}
--- a/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/utilities/MarkBits.java Tue Feb 19 10:02:42 2019 +0100
+++ b/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/utilities/MarkBits.java Tue Feb 19 10:02:54 2019 +0100
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2019, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -41,8 +41,7 @@
start = reserved.start();
end = reserved.end();
long numOopHandles = end.minus(start) / VM.getVM().getOopSize();
- // FIXME: will have trouble with larger heap sizes
- bits = new BitMap((int) numOopHandles);
+ bits = heap.createBitMap(numOopHandles);
}
public void clear() {
@@ -60,34 +59,22 @@
}
OopHandle handle = obj.getHandle();
- // FIXME: will have trouble with larger heap sizes
long idx = handle.minus(start) / VM.getVM().getOopSize();
- if ((idx < 0) || (idx >= bits.size())) {
- System.err.println("MarkBits: WARNING: object " + handle + " outside of heap, ignoring");
- return false;
- }
- int intIdx = (int) idx;
- if (bits.at(intIdx)) {
+ if (bits.at(idx)) {
return false; // already marked
}
- bits.atPut(intIdx, true);
+ bits.atPut(idx, true);
return true;
}
/** Forces clearing of a given mark bit. */
public void clear(Oop obj) {
OopHandle handle = obj.getHandle();
- // FIXME: will have trouble with larger heap sizes
long idx = handle.minus(start) / VM.getVM().getOopSize();
- if ((idx < 0) || (idx >= bits.size())) {
- System.err.println("MarkBits: WARNING: object " + handle + " outside of heap, ignoring");
- return;
- }
- int intIdx = (int) idx;
- bits.atPut(intIdx, false);
+ bits.atPut(idx, false);
}
- private BitMap bits;
+ private BitMapInterface bits;
private Address start;
private Address end;
}