public AweStream(UInt32 capacity)
{
unsafe
{
// Enable the privilege of lock memory.
lock (_SetLockPagesPrivilegeLockObj)
{
if (!_SetLockPagesPrivilegeOk)
{
LoggedSetLockPagesPrivilege.SetLockPagesPrivilege(System.Diagnostics.Process.GetCurrentProcess(), true);
_SetLockPagesPrivilegeOk = true;
}
}
General.SYSTEM_INFO sysInfo;
General.GetSystemInfo(out sysInfo); // fill the system information structure
_PageSize = sysInfo.dwPageSize;
if ((capacity % _PageSize) != 0)
{
_NumberOfPages = capacity / _PageSize + 1;
}
else
{
_NumberOfPages = capacity / _PageSize;
}
_PFNArraySize = (UInt32)(_NumberOfPages * sizeof(UInt64 *)); // memory to request for PFN array
_PFNArray = Marshal.AllocHGlobal((int)_PFNArraySize);
UInt32 numberOfPagesInitial = _NumberOfPages;
if (!AweApi.AllocateUserPhysicalPages(System.Diagnostics.Process.GetCurrentProcess().Handle,
ref _NumberOfPages, _PFNArray))
{
Dispose();
throw new AweStreamException("Cannot allocate physical pages", AweStreamException.Reason.CannotAllocatePhysicalPages);
}
_AweAllocated = true;
if (numberOfPagesInitial != _NumberOfPages)
{
Dispose();
throw new AweStreamException(string.Format("Allocated only {0} pages.", _NumberOfPages),
AweStreamException.Reason.AweMemoryNotEnough);
}
_Capacity = _PageSize * _NumberOfPages;
}
}
public new void Dispose()
{
try
{
UnMap();
}
catch
{
}
try
{
if (_AweAllocated)
{
AweApi.FreeUserPhysicalPages(System.Diagnostics.Process.GetCurrentProcess().Handle,
ref _NumberOfPages, _PFNArray);
_AweAllocated = false;
}
}
catch
{
}
try
{
if (_PFNArray != IntPtr.Zero)
{
Marshal.FreeHGlobal(_PFNArray);
_PFNArray = IntPtr.Zero;
}
}
catch
{
}
try
{
}
catch
{
base.Dispose();
}
}
public void UnMap()
{
unsafe
{
if (_VirtualAddress != null)
{
if (!AweApi.MapUserPhysicalPages(_VirtualAddress, _NumberOfPages, IntPtr.Zero))
{
throw new AweStreamException(string.Format("UnMapUserPhysicalPages failed ({0})", General.GetLastError()),
AweStreamException.Reason.UnMapUserPhysicalPagesFail);
}
if (!AweApi.VirtualFree(_VirtualAddress, 0, AweApi.MEM_RELEASE))
{
throw new AweStreamException(string.Format("VitualFree failed ({0})", General.GetLastError()),
AweStreamException.Reason.VitualFreeFail);
}
_VirtualAddress = null;
}
}
}
public void Map(bool readOnly)
{
unsafe
{
if (IsMapped)
{
return;
}
if (readOnly)
{
_VirtualAddress = AweApi.VirtualAlloc(null, Capacity, AweApi.MEM_RESERVE | AweApi.MEM_PHYSICAL,
AweApi.PAGE_READONLY);
}
else
{
_VirtualAddress = AweApi.VirtualAlloc(null, Capacity, AweApi.MEM_RESERVE | AweApi.MEM_PHYSICAL,
AweApi.PAGE_READWRITE);
}
if (_VirtualAddress == null)
{
throw new AweStreamException("Cannot reserve memory.", AweStreamException.Reason.CannotReserveMemory);
}
if (!AweApi.MapUserPhysicalPages(_VirtualAddress, _NumberOfPages, _PFNArray))
{
AweApi.VirtualFree(_VirtualAddress, Capacity, AweApi.MEM_RELEASE);
_VirtualAddress = null;
throw new AweStreamException(string.Format("MapUserPhysicalPages failed ({0})", General.GetLastError()),
AweStreamException.Reason.MapUserPhysicalPagesFail);
}
_CanWrite = !readOnly;
}
}
