private unsafe void CompactHeapObjects(UIntPtr previousEnd)
{
while (!this.relocationQueue.IsEmpty)
{
UIntPtr sourceAddress = this.relocationQueue.Read();
UIntPtr destinationAddress = this.relocationQueue.Read();
UIntPtr runLength = this.relocationQueue.Read();
if (previousEnd != destinationAddress)
{
VTable.Assert(previousEnd < destinationAddress);
if (PageTable.Page(destinationAddress) !=
PageTable.Page(previousEnd + PreHeader.Size))
{
if (!PageTable.PageAligned(previousEnd))
{
UIntPtr pageLimit = PageTable.PagePad(previousEnd);
BumpAllocator.WriteUnusedMarker(previousEnd);
previousEnd += UIntPtr.Size;
Util.MemClear(previousEnd,
pageLimit - previousEnd);
}
if (!PageTable.PageAligned(destinationAddress))
{
// This only happens before pinned objects and
// large objects
UIntPtr start =
PageTable.PageAlign(destinationAddress);
VTable.Assert(previousEnd <= start);
while (start < destinationAddress)
{
Allocator.WriteAlignment(start);
start += UIntPtr.Size;
}
}
UIntPtr objAddr = destinationAddress + PreHeader.Size;
InteriorPtrTable.SetFirst(objAddr);
}
else
{
VTable.Assert(previousEnd < destinationAddress);
UIntPtr start = previousEnd;
while (start < destinationAddress)
{
Allocator.WriteAlignment(start);
start += UIntPtr.Size;
}
}
}
Util.MemCopy(destinationAddress, sourceAddress, runLength);
previousEnd = destinationAddress + runLength;
}
// Zero out the end of the allocation page
if (!PageTable.PageAligned(previousEnd))
{
UIntPtr pageLimit = PageTable.PagePad(previousEnd);
Util.MemClear(previousEnd, pageLimit - previousEnd);
}
this.relocationQueue.Cleanup(true);
}
public static unsafe Object CompilerAllocateGenerational
(VTable vtable, Thread currentThread, UIntPtr bytes, uint alignment)
{
VTable.Assert((alignment == 4) ||
((alignment == 8) && (UIntPtr.Size == 8)) ||
((alignment == 8) && (PreHeader.Size == 4)),
"Unsupported object layout");
VTable.Assert(UIntPtr.Size == PreHeader.Size,
"Unsupported preheader size");
VTable.Assert
(Util.IsAligned((uint)PreHeader.Size + (uint)PostHeader.Size,
alignment),
"Unsupported header sizes");
UIntPtr preHeaderAddr =
MixinThread(currentThread).bumpAllocator.allocPtr;
// allocPtr is only needed when alignment needs to be checked. It
// stores the beginning of the region to be allocation including
// a possible alignment token.
UIntPtr allocPtr = UIntPtr.Zero;
if ((alignment == 8) && (UIntPtr.Size == 4))
{
allocPtr = preHeaderAddr;
preHeaderAddr = Util.Pad(preHeaderAddr, (UIntPtr)alignment);
}
UIntPtr bound = preHeaderAddr + bytes;
UIntPtr limitPtr =
MixinThread(currentThread).bumpAllocator.zeroedLimit;
if (bound <= limitPtr)
{
if ((alignment == 8) && (UIntPtr.Size == 4))
{
// Store alignment token at allocPtr. This will be where an
// alignment token should go if 'preHeaderAddr' was
// bumped...
Allocator.WriteAlignment(allocPtr);
// ... or the alignment token is where the object header
// should be. This code zeroes the object header regardless
// and avoids a branch in this fast path.
*(UIntPtr *)preHeaderAddr = UIntPtr.Zero;
}
MixinThread(currentThread).bumpAllocator.allocPtr = bound;
UIntPtr objAddr = preHeaderAddr + PreHeader.Size;
Object obj = Magic.fromAddress(objAddr);
obj.vtable = vtable;
return(obj);
}
return(GC.AllocateObjectNoInline(vtable, currentThread));
}
internal static UIntPtr AlignedObjectPtr(UIntPtr startAddr,
uint alignment)
{
if (alignment > UIntPtr.Size)
{
uint alignmentMask = alignment - 1;
int offset = PostHeader.Size;
while (((startAddr + offset) & alignmentMask) != 0)
{
Allocator.WriteAlignment(startAddr - PreHeader.Size);
startAddr += UIntPtr.Size;
}
}
return(startAddr);
}
internal static UIntPtr AlignedAllocationPtr(UIntPtr startAddr,
UIntPtr limitAddr,
uint alignment)
{
if (alignment > UIntPtr.Size)
{
uint alignmentMask = alignment - 1;
int offset = PreHeader.Size + PostHeader.Size;
while (((startAddr + offset) & alignmentMask) != 0 &&
startAddr < limitAddr)
{
Allocator.WriteAlignment(startAddr);
startAddr += UIntPtr.Size;
}
}
return(startAddr);
}
// Interface with the compiler!
internal static unsafe UIntPtr AllocateBig(UIntPtr numBytes,
uint alignment,
Thread currentThread)
{
// Pretenure Trigger
pretenuredSinceLastFullGC += numBytes;
if (pretenuredSinceLastFullGC > PretenureHardGCTrigger)
{
GC.InvokeMajorCollection(currentThread);
}
// Potentially Join a collection
GC.CheckForNeededGCWork(currentThread);
int maxAlignmentOverhead = unchecked ((int)alignment) - UIntPtr.Size;
UIntPtr pageCount =
PageTable.PageCount(numBytes + maxAlignmentOverhead);
bool fCleanPages = true;
UIntPtr page = PageManager.EnsurePages(currentThread, pageCount,
largeObjectGeneration,
ref fCleanPages);
int unusedBytes =
unchecked ((int)(PageTable.RegionSize(pageCount) - numBytes));
int unusedCacheLines =
unchecked ((int)(unusedBytes - maxAlignmentOverhead)) >> 5;
int pageOffset = 0;
if (unusedCacheLines != 0)
{
pageOffset = (bigOffset % unusedCacheLines) << 5;
bigOffset++;
}
UIntPtr pageStart = PageTable.PageAddr(page);
for (int i = 0; i < pageOffset; i += UIntPtr.Size)
{
Allocator.WriteAlignment(pageStart + i);
}
UIntPtr unalignedStartAddr = pageStart + pageOffset;
UIntPtr startAddr =
Allocator.AlignedAllocationPtr(unalignedStartAddr,
pageStart + unusedBytes,
alignment);
pageOffset +=
unchecked ((int)(uint)(startAddr - unalignedStartAddr));
if (pageOffset < unusedBytes)
{
BumpAllocator.WriteUnusedMarker(pageStart + pageOffset + numBytes);
}
UIntPtr resultAddr = startAddr + PreHeader.Size;
InteriorPtrTable.SetFirst(resultAddr);
VTable.Assert(PageTable.Page(resultAddr) <
PageTable.Page(startAddr + numBytes - 1),
"Big object should cross pages");
if (GC.remsetType == RemSetType.Cards)
{
#if DONT_RECORD_OBJALLOC_IN_OFFSETTABLE
#else
OffsetTable.SetLast(resultAddr);
#endif
}
return(resultAddr);
}
internal void CleanPinnedPages()
{
if (pinnedPageList == null || pinnedPageList.Count == 0)
{
return;
}
int pageIndex = 0;
int limit = pinnedPageList.Count;
UIntPtr lastPostPinnedAddr = UIntPtr.Zero;
while (pageIndex < limit)
{
UIntPtr startPage = (UIntPtr)pinnedPageList[pageIndex];
UIntPtr endPage = startPage + 1;
pageIndex++;
while (pageIndex < limit &&
(UIntPtr)pinnedPageList[pageIndex] == endPage)
{
pageIndex++;
endPage++;
}
// Zero out the area between the start of the page and
// the first object on the page
UIntPtr firstObjectAddr = FirstPinnedObjectAddr(startPage);
UIntPtr firstAddr = firstObjectAddr - PreHeader.Size;
UIntPtr trashAddr = PageTable.PageAddr(startPage);
if (firstAddr < trashAddr)
{
// The first object "spills" into the previous page,
// presumably by no more than HEADER_BYTES bytes
VTable.Assert(
PageTable.Page(firstAddr) == startPage - 1,
"Semispace:RegisterPinnedReference:3");
// Prepare to zero the preceding page unless it also
// had pinned data on it
trashAddr = PageTable.PageAddr(startPage - 1);
InteriorPtrTable.ClearFirst(startPage - 1);
if (trashAddr >= lastPostPinnedAddr)
{
// Need to mark the spilled-onto page live to
// keep the spilled data around
PageType fromSpaceType =
PageTable.Type(startPage - 1);
VTable.Assert(
PageTable.IsZombiePage(fromSpaceType),
"Semispace:RegisterPinnedReference:4");
PageType toSpaceType =
PageTable.ZombieToLive(fromSpaceType);
PageTable.SetType(startPage - 1, toSpaceType);
}
}
// If lastPostPinnedAddr is on the page that trashAddr
// starts, pinned data from the last run of pinned pages
// and pinned data from this run of pinned data are on the
// same page, so just write alignment tokens from
// lastPostPinnedAddr to the first pinned object.
// Otherwise, write an unused marker at lastPostPinnedAddr
// since the rest of its page must be copied or dead.
if (trashAddr < lastPostPinnedAddr)
{
trashAddr = lastPostPinnedAddr;
}
else
{
CleanPageTail(lastPostPinnedAddr);
}
if (GC.remsetType == RemSetType.Cards &&
trashAddr < firstAddr)
{
UIntPtr firstCard = CardTable.CardNo(trashAddr);
UIntPtr lastCard = CardTable.CardNo(firstAddr - 1);
if (!OffsetTable.NoObjectPtrToTheCard(firstCard))
{
UIntPtr offset = OffsetTable.GetOffset(firstCard);
UIntPtr objPtr =
CardTable.CardAddr(firstCard) + offset;
UIntPtr size = OffsetTable.ObjectSize(objPtr);
VTable.Assert
((objPtr + size - PreHeader.Size <= trashAddr) ||
(objPtr >= trashAddr),
"Object should be totally "
+ "above or below trashAddr");
if (objPtr >= trashAddr)
{
// The offset in this card needs to be updated
OffsetTable.ClearCards(firstCard, firstCard);
}
}
OffsetTable.ClearCards(firstCard + 1, lastCard - 1);
if (lastCard != CardTable.CardNo(firstObjectAddr))
{
OffsetTable.ClearCards(lastCard, lastCard);
}
else
{
VTable.Assert(OffsetTable.GetOffset(lastCard)
>= (firstObjectAddr
- CardTable.CardAddr(lastCard)),
"wrong offset");
}
}
{
// trashAddr should go back at most one page.
UIntPtr trashPage = PageTable.Page(trashAddr);
UIntPtr firstObjectAddrPage =
PageTable.Page(firstObjectAddr);
VTable.Assert((trashPage == firstObjectAddrPage - 1) ||
(trashPage == firstObjectAddrPage));
}
// If the InteriorPtrTable already had a value, then this is
// redundant, but if the call to First above has to compute
// the value, then (since it won't store it in the table) we
// should store it. Why? At this point the previous page
// would be "connected" to this one. After this collection
// the previous page will be unused or re-used and unrelated
// to this page and subsequent calls to First would then
// rely on it making the leap between unrelated pages.
InteriorPtrTable.SetFirst(firstObjectAddr);
while (trashAddr < firstAddr)
{
Allocator.WriteAlignment(trashAddr);
trashAddr += UIntPtr.Size;
}
// Zero out the area between the last whole object on
// the last page and the end of the last page
UIntPtr pastAddr = PostPinnedObjectAddr(endPage);
UIntPtr newEndPage =
PageTable.Page(PageTable.PagePad(pastAddr));
while (endPage < newEndPage)
{
// The last object spills into the next page(s), so
// mark those page(s) live
PageType fromPageType = PageTable.Type(endPage);
if (PageTable.IsZombiePage(fromPageType))
{
PageType toSpaceType =
PageTable.ZombieToLive(fromPageType);
PageTable.SetType(endPage, toSpaceType);
}
else
{
// final page might be live already because
// something else on it was pinned.
// pageIndex has already been incremented,
// so it points to the start of the next
// set of contiguous pages
VTable.Assert(
PageTable.IsLiveGcPage(fromPageType) &&
pageIndex < limit &&
endPage ==
(UIntPtr)pinnedPageList[pageIndex],
"Semispace:RegisterPinnedReference:5");
}
++endPage;
}
lastPostPinnedAddr = pastAddr;
}
CleanPageTail(lastPostPinnedAddr);
pinnedPageList = null;
comparer = null;
}
