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src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/gc/z/ZPage.java
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*** 22,53 ****
*
*/
package sun.jvm.hotspot.gc.z;
import sun.jvm.hotspot.debugger.Address;
import sun.jvm.hotspot.runtime.VM;
import sun.jvm.hotspot.runtime.VMObject;
import sun.jvm.hotspot.runtime.VMObjectFactory;
import sun.jvm.hotspot.types.CIntegerField;
import sun.jvm.hotspot.types.Type;
import sun.jvm.hotspot.types.TypeDataBase;
! public class ZPage extends VMObject {
private static CIntegerField typeField;
private static long virtualFieldOffset;
private static long forwardingFieldOffset;
static {
VM.registerVMInitializedObserver((o, d) -> initialize(VM.getVM().getTypeDataBase()));
}
static private synchronized void initialize(TypeDataBase db) {
Type type = db.lookupType("ZPage");
typeField = type.getCIntegerField("_type");
virtualFieldOffset = type.getField("_virtual").getOffset();
forwardingFieldOffset = type.getField("_forwarding").getOffset();
}
public ZPage(Address addr) {
super(addr);
--- 22,68 ----
*
*/
package sun.jvm.hotspot.gc.z;
+ import java.util.ArrayList;
+ import java.util.List;
+
import sun.jvm.hotspot.debugger.Address;
+ import sun.jvm.hotspot.debugger.OopHandle;
+ import sun.jvm.hotspot.gc.shared.LiveRegionsProvider;
+ import sun.jvm.hotspot.memory.MemRegion;
+ import sun.jvm.hotspot.oops.Oop;
+ import sun.jvm.hotspot.oops.UnknownOopException;
import sun.jvm.hotspot.runtime.VM;
import sun.jvm.hotspot.runtime.VMObject;
import sun.jvm.hotspot.runtime.VMObjectFactory;
+ import sun.jvm.hotspot.types.AddressField;
import sun.jvm.hotspot.types.CIntegerField;
import sun.jvm.hotspot.types.Type;
import sun.jvm.hotspot.types.TypeDataBase;
! public class ZPage extends VMObject implements LiveRegionsProvider {
private static CIntegerField typeField;
+ private static CIntegerField seqnumField;
private static long virtualFieldOffset;
+ private static AddressField topField;
+ private static CIntegerField refcountField;
private static long forwardingFieldOffset;
static {
VM.registerVMInitializedObserver((o, d) -> initialize(VM.getVM().getTypeDataBase()));
}
static private synchronized void initialize(TypeDataBase db) {
Type type = db.lookupType("ZPage");
typeField = type.getCIntegerField("_type");
+ seqnumField = type.getCIntegerField("_seqnum");
virtualFieldOffset = type.getField("_virtual").getOffset();
+ topField = type.getAddressField("_top");
+ refcountField = type.getCIntegerField("_refcount");
forwardingFieldOffset = type.getField("_forwarding").getOffset();
}
public ZPage(Address addr) {
super(addr);
*** 55,70 ****
private byte type() {
return typeField.getJByte(addr);
}
private ZVirtualMemory virtual() {
! return (ZVirtualMemory)VMObjectFactory.newObject(ZVirtualMemory.class, addr.addOffsetTo(virtualFieldOffset));
}
private ZForwardingTable forwarding() {
! return (ZForwardingTable)VMObjectFactory.newObject(ZForwardingTable.class, addr.addOffsetTo(forwardingFieldOffset));
}
long start() {
return virtual().start();
}
--- 70,113 ----
private byte type() {
return typeField.getJByte(addr);
}
+ private int seqnum() {
+ return seqnumField.getJInt(addr);
+ }
+
private ZVirtualMemory virtual() {
! return VMObjectFactory.newObject(ZVirtualMemory.class, addr.addOffsetTo(virtualFieldOffset));
! }
!
! private Address top() {
! return topField.getValue(addr);
! }
!
! private int refcount() {
! // refcount is uint32_t so need to be cautious when using this field.
! return refcountField.getJInt(addr);
}
private ZForwardingTable forwarding() {
! return VMObjectFactory.newObject(ZForwardingTable.class, addr.addOffsetTo(forwardingFieldOffset));
! }
!
! private boolean is_forwarding() {
! return forwarding().table() != null;
! }
!
! private boolean is_relocatable() {
! return is_active() && seqnum() < ZGlobals.ZGlobalSeqNum();
! }
!
! private boolean isPageRelocating() {
! assert(is_active());
! // is_forwarding(): Has a (relocation) forwarding table
! // is_relocatable(): Has not been freed yet
! return is_forwarding() && is_relocatable();
}
long start() {
return virtual().start();
}
*** 96,112 ****
// There's no relocate operation in the SA.
// Mimic object pinning and return the good view of the from object.
return ZAddress.good(from);
}
-
long object_alignment_shift() {
if (type() == ZGlobals.ZPageTypeSmall) {
return ZGlobals.ZObjectAlignmentSmallShift();
} else if (type() == ZGlobals.ZPageTypeMedium) {
return ZGlobals.ZObjectAlignmentMediumShift;
} else {
assert(type() == ZGlobals.ZPageTypeLarge);
return ZGlobals.ZObjectAlignmentLargeShift;
}
}
}
--- 139,244 ----
// There's no relocate operation in the SA.
// Mimic object pinning and return the good view of the from object.
return ZAddress.good(from);
}
long object_alignment_shift() {
if (type() == ZGlobals.ZPageTypeSmall) {
return ZGlobals.ZObjectAlignmentSmallShift();
} else if (type() == ZGlobals.ZPageTypeMedium) {
return ZGlobals.ZObjectAlignmentMediumShift;
} else {
assert(type() == ZGlobals.ZPageTypeLarge);
return ZGlobals.ZObjectAlignmentLargeShift;
}
}
+
+ long objectAlignmentSize() {
+ return 1 << object_alignment_shift();
+ }
+
+ public boolean is_active() {
+ return refcount() != 0;
+ }
+
+ private long getObjectSize(Address good) {
+ OopHandle handle = good.addOffsetToAsOopHandle(0);
+ Oop obj = null;
+
+ try {
+ obj = VM.getVM().getObjectHeap().newOop(handle);
+ } catch (UnknownOopException exp) {
+ throw new RuntimeException(" UnknownOopException " + exp);
+ }
+
+ return VM.getVM().alignUp(obj.getObjectSize(), objectAlignmentSize());
+ }
+
+ private void addNotRelocatedRegions(List<MemRegion> regions) {
+ MemRegion mr = null;
+
+ // Some objects have already been forwarded to new locations.
+ long topValue = top().asLongValue();
+ for (long offsetValue = start(); offsetValue < topValue;) {
+ Address from = ZAddress.good(ZUtils.longToAddress(offsetValue));
+
+ Address to = relocate_object(from);
+
+ long byteSize;
+ try {
+ byteSize = getObjectSize(to);
+ } catch (Exception e) {
+ // Parsing the ZHeap is inherently unsafe
+ // when classes have been unloaded. Dead objects
+ // might have stale Klass pointers, and there's
+ // no way to get the size of the dead object.
+ //
+ // If possible, run with -XX:-ClassUnloading
+ // to ensure that all Klasses are kept alive.
+ System.err.println("Unparsable regions found. Skipping: "
+ + from
+ + " "
+ + from.addOffsetTo(topValue - offsetValue));
+
+ // Can't proceed further. Just return the collected regions.
+ return;
+ }
+
+ if (from.equals(to)) {
+ // Not relocated - add region
+ if (mr == null) {
+ mr = new MemRegion(from, 0 /* wordSize */);
+ regions.add(mr);
+ }
+
+ long wordSize = byteSize / VM.getVM().getBytesPerWord();
+ mr.setWordSize(mr.wordSize() + wordSize);
+ } else {
+ // Forwarded somewhere else, split region.
+ mr = null;
+ }
+
+ offsetValue += byteSize;
+ }
+ }
+
+ public List<MemRegion> getLiveRegions() {
+ List<MemRegion> res = new ArrayList<>();
+
+ if (isPageRelocating()) {
+ addNotRelocatedRegions(res);
+ } else {
+ Address start = ZAddress.good(ZUtils.longToAddress(start()));
+
+ // Can't convert top() to a "good" address because it might
+ // be at the top of the "offset" range, and therefore also
+ // looks like one of the color bits. Instead use the "good"
+ // address and add the size.
+ long size = top().asLongValue() - start();
+ Address end = start.addOffsetTo(size);
+
+ res.add(new MemRegion(start, end));
+ }
+
+ return res;
+ }
}
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