internal unsafe override void Visit(UIntPtr *loc)
{
UIntPtr addr = *loc;
UIntPtr page = PageTable.Page(addr);
PageType pageType = PageTable.Type(page);
if (!PageTable.IsZombiePage(pageType))
{
VTable.Assert(PageTable.IsGcPage(pageType) ||
PageTable.IsNonGcPage(pageType) ||
PageTable.IsStackPage(pageType) ||
PageTable.IsSharedPage(pageType));
return;
}
UIntPtr vtableAddr = Allocator.GetObjectVTable(addr);
// Mark object
if (vtableAddr == UIntPtr.Zero)
{
VTable.DebugPrint("Found null vtable in MarkReference (loc = 0x{0:x8}, addr = 0x{1:x8})\n",
__arglist(((UIntPtr)loc), addr));
VTable.NotReached();
}
*loc = vtableAddr;
Allocator.SetObjectVTable(addr, (UIntPtr)loc + 1);
// If first visit to the object, schedule visit of fields
if ((vtableAddr & 0x1) == 0)
{
MarkVisit(addr, vtableAddr & (UIntPtr) ~2U);
}
}
internal unsafe override void Visit(UIntPtr *loc)
{
UIntPtr addr = *loc;
UIntPtr page = PageTable.Page(addr);
PageType pageType = PageTable.Type(page);
if (!PageTable.IsZombiePage(pageType))
{
VTable.Assert(PageTable.IsGcPage(pageType) ||
PageTable.IsNonGcPage(pageType) ||
PageTable.IsStackPage(pageType) ||
PageTable.IsSharedPage(pageType));
return;
}
UIntPtr vtableAddr = Allocator.GetObjectVTable(addr);
if ((vtableAddr & 0x1) == 0x1)
{
// Link this field to be updated
*loc = vtableAddr;
Allocator.SetObjectVTable(addr, (UIntPtr)loc + 1);
}
else
{
// Zero the reference (not marked)
*loc = UIntPtr.Zero;
}
}
// Reference updates and object relocation
private unsafe UIntPtr ForwardReferences(PageType generation,
out UIntPtr oldAllocPtr)
{
VTable.Assert(IsValidGeneration((int)generation));
UIntPtr destPage = UIntPtr.Zero;
UIntPtr destCursor;
UIntPtr destLimit;
PageType destGeneration;
if (generation < MAX_GENERATION)
{
destGeneration = generation + 1;
}
else
{
destGeneration = MAX_GENERATION;
}
destCursor = UIntPtr.Zero;
destLimit = UIntPtr.Zero;
oldAllocPtr = destCursor;
UIntPtr runLength = UIntPtr.Zero;
for (UIntPtr i = UIntPtr.Zero; i < PageTable.pageTableCount; i++)
{
if (!IsMyZombiePage(i))
{
continue;
}
UIntPtr deltaBytes = (UIntPtr)0x80000000;
UIntPtr sourceCursor = PageTable.PageAddr(i);
do
{
i++;
} while (i < PageTable.pageTableCount && IsMyZombiePage(i));
UIntPtr sourceLimit = PageTable.PageAddr(i);
while (true)
{
if (sourceCursor >= sourceLimit)
{
break;
}
if (Allocator.IsAlignmentMarkerAddr(sourceCursor))
{
sourceCursor += UIntPtr.Size;
deltaBytes += UIntPtr.Size;
continue;
}
if (BumpAllocator.IsUnusedMarkerAddr(sourceCursor))
{
sourceCursor += UIntPtr.Size;
sourceCursor = PageTable.PagePad(sourceCursor);
deltaBytes = (UIntPtr)0x80000000;
continue;
}
UIntPtr objectAddr = sourceCursor + PreHeader.Size;
UIntPtr vtableOrMarker =
Allocator.GetObjectVTable(objectAddr);
if (vtableOrMarker == UIntPtr.Zero)
{
// We found the end of an allocation page
sourceCursor = PageTable.PagePad(sourceCursor);
deltaBytes = (UIntPtr)0x80000000;
continue;
}
UIntPtr vtableAddr;
if ((vtableOrMarker & 1) != 0)
{
UIntPtr temp = *(UIntPtr *)(vtableOrMarker - 1);
while ((temp & 1) != 0)
{
temp = *(UIntPtr *)(temp - 1);
}
VTable.Assert(PageTable.IsNonGcPage(PageTable.Type(PageTable.Page(temp))));
vtableAddr = temp;
if ((temp & 2) != 0)
{
// Found pinned object
SkipDestinationAreas(ref destPage, destCursor,
ref destLimit,
sourceCursor);
deltaBytes -= (sourceCursor - destCursor);
destCursor = sourceCursor;
vtableAddr -= 2; // Remove "pinned" bit
}
Allocator.SetObjectVTable(objectAddr, vtableAddr);
}
else
{
vtableAddr = vtableOrMarker;
}
VTable vtable =
Magic.toVTable(Magic.fromAddress(vtableAddr));
UIntPtr objectSize =
ObjectLayout.ObjectSize(objectAddr, vtable);
VTable.Assert(objectSize > 0);
if ((vtableOrMarker & 1) != 0)
{
if (GenerationalCollector.IsLargeObjectSize
(objectSize))
{
// Don't move large objects
SkipDestinationAreas(ref destPage,
destCursor,
ref destLimit,
sourceCursor);
UIntPtr localDelta =
sourceCursor - destCursor;
deltaBytes -= localDelta;
if (deltaBytes == UIntPtr.Zero &&
runLength != UIntPtr.Zero)
{
runLength += localDelta;
}
destCursor = sourceCursor;
UIntPtr objLimit = sourceCursor + objectSize;
UIntPtr pageEndAddr = PageTable.PagePad(objLimit);
objectSize = (pageEndAddr - sourceCursor);
}
else if (destCursor + objectSize > destLimit)
{
UIntPtr oldDestCursor = destCursor;
FindDestinationArea(ref destPage,
ref destCursor,
ref destLimit,
objectSize,
destGeneration);
VTable.Assert(destCursor <= sourceCursor);
VTable.Assert(destCursor + objectSize <=
destLimit);
deltaBytes -= (destCursor - oldDestCursor);
}
else if (vtable.baseAlignment > UIntPtr.Size)
{
uint alignmentMask = vtable.baseAlignment - 1;
int offset = PreHeader.Size + UIntPtr.Size;
while (((destCursor + offset) & alignmentMask) != 0)
{
destCursor += UIntPtr.Size;
deltaBytes -= UIntPtr.Size;
if (deltaBytes == UIntPtr.Zero &&
runLength != UIntPtr.Zero)
{
runLength += UIntPtr.Size;
}
}
}
if (runLength == UIntPtr.Zero ||
deltaBytes != UIntPtr.Zero)
{
if (runLength != UIntPtr.Zero)
{
RegisterRelocationEnd(runLength);
}
RegisterRelocationStart(sourceCursor,
destCursor);
deltaBytes = UIntPtr.Zero;
runLength = UIntPtr.Zero;
}
UIntPtr newObjectAddr = destCursor + PreHeader.Size;
do
{
UIntPtr *ptrAddr = (UIntPtr *)(vtableOrMarker - 1);
vtableOrMarker = *ptrAddr;
*ptrAddr = newObjectAddr;
} while ((vtableOrMarker & 1) != 0);
destCursor += objectSize;
runLength += objectSize;
}
else
{
deltaBytes += objectSize;
if (runLength != UIntPtr.Zero)
{
RegisterRelocationEnd(runLength);
}
runLength = UIntPtr.Zero;
}
sourceCursor += objectSize;
}
}
if (runLength != UIntPtr.Zero)
{
RegisterRelocationEnd(runLength);
}
return(destCursor);
}