private void RetractPage()
{
UnmanagedPageList.pageCache.AddHead(this.stackPage);
this.stackPage = this.pageList.RemoveHead();
this.stackBottom = UnmanagedPageList.FirstPageAddr(this.stackPage);
this.stackTop = UnmanagedPageList.EndPageAddr(this.stackPage);
this.stackPtr = this.stackTop;
}
private void SetCursor(UIntPtr pageAddr)
{
UIntPtr *preFirstAddr =
UnmanagedPageList.FirstPageAddr(pageAddr) - 1;
if (pageAddr == lastPageStart)
{
this.currentCursor = new PageCursor(preFirstAddr,
this.lastPageLimit);
}
else
{
UIntPtr *endAddr = UnmanagedPageList.EndPageAddr(pageAddr);
this.currentCursor = new PageCursor(preFirstAddr, endAddr);
}
}
private void AdvanceWritePage()
{
UIntPtr pageAddr;
if (UnmanagedPageList.pageCache.IsEmpty)
{
bool fCleanPages = true;
UIntPtr page = PageManager.EnsurePages(null, (UIntPtr)1,
PageType.System,
ref fCleanPages);
pageAddr = PageTable.PageAddr(page);
}
else
{
pageAddr = UnmanagedPageList.pageCache.RemoveHead();
}
this.pageList.AddTail(pageAddr);
this.writeCursor =
new PageCursor(UnmanagedPageList.FirstPageAddr(pageAddr),
UnmanagedPageList.EndPageAddr(pageAddr));
}
private void AdvancePage()
{
if (this.stackPage != UIntPtr.Zero)
{
this.pageList.AddHead(this.stackPage);
}
if (UnmanagedPageList.pageCache.IsEmpty)
{
bool fCleanPages = true;
UIntPtr page = PageManager.EnsurePages(null, (UIntPtr)1,
PageType.System,
ref fCleanPages);
this.stackPage = PageTable.PageAddr(page);
}
else
{
this.stackPage = UnmanagedPageList.pageCache.RemoveHead();
}
this.stackBottom = UnmanagedPageList.FirstPageAddr(this.stackPage);
this.stackPtr = this.stackBottom;
this.stackTop = UnmanagedPageList.EndPageAddr(this.stackPage);
}
private void AdvanceReadPage()
{
if (this.pageList.IsEmpty)
{
return;
}
if (this.readPage != UIntPtr.Zero)
{
UnmanagedPageList.pageCache.AddHead(this.readPage);
}
this.readPage = this.pageList.RemoveHead();
UIntPtr *startPtr = UnmanagedPageList.FirstPageAddr(this.readPage);
UIntPtr *limitPtr;
if (this.pageList.IsEmpty)
{
limitPtr = this.writeCursor.cursor;
}
else
{
limitPtr = UnmanagedPageList.EndPageAddr(this.readPage);
}
this.readCursor = new PageCursor(startPtr, limitPtr);
}