internal static void Initialize(UIntPtr systemMemorySize)
{
allocPtr = MemoryManager.AllocateMemory(systemMemorySize);
limitPtr = allocPtr + systemMemorySize;
if (GC.gcType != GCType.NullCollector)
{
PageManager.SetStaticDataPages(allocPtr, systemMemorySize);
#if !SINGULARITY
PageTable.SetProcess(PageTable.Page(allocPtr),
PageTable.PageCount(systemMemorySize));
#endif
}
}
// Tell the GC that a certain data area is no longer allowed to
// contain off-limits, non-moveable data.
private static unsafe void SetUnallocatedPages(UIntPtr startAddr,
UIntPtr size)
{
UIntPtr startPage = PageTable.Page(startAddr);
UIntPtr endAddr = startAddr + size;
UIntPtr endPage = PageTable.Page(endAddr);
UIntPtr pageCount = endPage - startPage;
if (pageCount == 1)
{
PageTable.SetExtra(startPage, 0);
PageTable.SetType(startPage, PageType.Unallocated);
PageTable.SetProcess(startPage, 0);
}
else
{
PageTable.SetExtra(startPage, pageCount, 0);
PageTable.SetType(startPage, pageCount, PageType.Unallocated);
PageTable.SetProcess(startPage, pageCount, 0);
}
}
// Low-level routines based on the operating system interface
private static unsafe UIntPtr AllocateMemoryHelper(UIntPtr startAddr,
UIntPtr size)
{
void *result = VirtualAlloc((void *)startAddr,
size, MEM_RESERVE, PAGE_READWRITE);
VTable.Assert
(PageTable.Page((UIntPtr)result + size - 1)
< PageTable.pageTableCount,
"OutOfMemory: MemoryManager: memory doesn't fit in page table");
if (result != null)
{
Trace.Log(Trace.Area.Page,
"VirtualAlloc {0} at {1}",
__arglist(size, result));
VTable.Assert((startAddr == UIntPtr.Zero) ||
(result == (void *)startAddr));
void *area = VirtualAlloc(result, size,
MEM_COMMIT, PAGE_READWRITE);
if (PageTable.halPageDescriptor != null)
{
PageTable.CreateNewPageTablesIfNecessary(PageTable.Page((UIntPtr)result), PageTable.PageCount(size));
PageTable.SetProcess(PageTable.Page((UIntPtr)area),
PageTable.PageCount(size));
}
VTable.Assert(result == area);
#if HIMEM
// This assertion intends only to catch bugs in Bartok. But if
// the system (windows) frees memory before, the memory
// may be in low memory, and if we happen to get that
// memory, this assertion itself may not hold
VTable.Assert((UIntPtr)result >= PageTable.HIMEMStart,
("High memory is expected to be allocated in HIMEM mode"));
#endif
}
return(new UIntPtr(result));
}
private static void SetPageTypeClean(UIntPtr startPage,
UIntPtr pageCount,
PageType newType)
{
UIntPtr *tableAddr = (UIntPtr *)PageTable.PageAddr(startPage);
UIntPtr *tableCursor = tableAddr + 1;
UIntPtr dirtyCount = UIntPtr.Zero;
UIntPtr endPage = startPage + pageCount;
for (UIntPtr i = startPage; i < endPage; i++)
{
PageType pageType = PageTable.Type(i);
if (pageType == PageType.UnusedDirty)
{
PageTable.SetType(i, newType);
UIntPtr j = i + 1;
while (j < endPage &&
PageTable.Type(j) == PageType.UnusedDirty)
{
PageTable.SetType(j, newType);
j++;
}
UIntPtr dirtyStartAddr = PageTable.PageAddr(i);
UIntPtr dirtyEndAddr = PageTable.PageAddr(j);
* tableCursor++ = dirtyStartAddr;
* tableCursor++ = dirtyEndAddr - dirtyStartAddr;
dirtyCount++;
i = j - 1;
}
else
{
PageTable.SetType(i, newType);
}
}
*tableAddr = dirtyCount;
PageTable.SetProcess(startPage, pageCount);
}
internal static UIntPtr EnsurePages(Thread currentThread,
UIntPtr pageCount,
PageType newType,
ref bool fCleanPages)
{
if (currentThread != null)
{
GC.CheckForNeededGCWork(currentThread);
}
VTable.Deny(PageTable.IsUnusedPageType(newType));
// Try to find already allocated but unused pages
UIntPtr foundPages =
FindUnusedPages(currentThread, pageCount, newType);
if (foundPages != UIntPtr.Zero)
{
if (fCleanPages)
{
CleanFoundPages(foundPages);
}
else
{
fCleanPages = FoundOnlyCleanPages(foundPages);
}
return(foundPages);
}
// We need to allocate new pages
bool iflag = EnterMutex(currentThread);
try {
UIntPtr bytesNeeded = PageTable.RegionSize(pageCount);
UIntPtr allocSize = Util.Pad(bytesNeeded, heap_commit_size);
UIntPtr startAddr = MemoryManager.AllocateMemory(allocSize);
if (startAddr == UIntPtr.Zero)
{
if (heap_commit_size > os_commit_size)
{
allocSize = Util.Pad(bytesNeeded, os_commit_size);
startAddr = MemoryManager.AllocateMemory(allocSize);
}
}
if (startAddr == UIntPtr.Zero)
{
// BUGBUG: if in CMS, should wait on one complete GC cycle and
// the retry. for STW, we may get here even if the collector
// hasn't triggered just prior.
PageTable.Dump("Out of memory");
throw outOfMemoryException;
}
UIntPtr startPage = PageTable.Page(startAddr);
PageTable.SetType(startPage, pageCount, newType);
PageTable.SetProcess(startPage, pageCount);
UIntPtr extraPages =
PageTable.PageCount(allocSize) - pageCount;
if (extraPages > 0)
{
// Mark the new memory pages as allocated-but-unused
MarkUnusedPages(/* avoid recursive locking */ null,
startPage + pageCount, extraPages,
true);
}
return(startPage);
} finally {
LeaveMutex(currentThread, iflag);
}
}