public static void _DecrementRefCount(byte *objPtr)
{
if ((uint)objPtr < (uint)sizeof(GCHeader))
{
BasicConsole.SetTextColour(BasicConsole.error_colour);
BasicConsole.WriteLine("Error! GC can't decrement ref count of an object in low memory.");
BasicConsole.DelayOutput(5);
BasicConsole.SetTextColour(BasicConsole.default_colour);
}
GCHeader *gcHeaderPtr = (GCHeader *)(objPtr - sizeof(GCHeader));
if (CheckSignature(gcHeaderPtr))
{
gcHeaderPtr->RefCount--;
//If the ref count goes below 0 then there was a circular reference somewhere.
// In actuality we don't care we can just only do cleanup when the ref count is
// exactly 0.
if (gcHeaderPtr->RefCount == 0)
{
#if GC_TRACE
BasicConsole.WriteLine("Cleaned up object.");
#endif
Testing2.Object obj = (Testing2.Object)Utilities.ObjectUtilities.GetObject(objPtr);
if (obj is Testing2.Array)
{
//Decrement ref count of elements
Testing2.Array arr = (Testing2.Array)obj;
if (!arr.elemType.IsValueType)
{
Testing2.Object[] objArr = (Testing2.Object[])Utilities.ObjectUtilities.GetObject(objPtr);
for (int i = 0; i < arr.length; i++)
{
DecrementRefCount(objArr[i], true);
}
}
}
//Cleanup fields
FieldInfo *FieldInfoPtr = obj._Type.FieldTablePtr;
//Loop through all fields. The if-block at the end handles moving to parent
// fields.
while (FieldInfoPtr != null)
{
if (FieldInfoPtr->Size > 0)
{
Testing2.Type fieldType = (Testing2.Type)Utilities.ObjectUtilities.GetObject(FieldInfoPtr->FieldType);
if (!fieldType.IsValueType &&
!fieldType.IsPointer)
{
byte * fieldPtr = objPtr + FieldInfoPtr->Offset;
Testing2.Object theFieldObj = (Testing2.Object)Utilities.ObjectUtilities.GetObject(fieldPtr);
DecrementRefCount(theFieldObj, true);
#if GC_TRACE
BasicConsole.WriteLine("Cleaned up field.");
#endif
}
FieldInfoPtr++;
}
if (FieldInfoPtr->Size == 0)
{
FieldInfoPtr = (FieldInfo *)FieldInfoPtr->FieldType;
}
}
AddObjectToCleanup(gcHeaderPtr, objPtr);
}
}
}
public static void *NewArr(int length, Testing2.Type elemType)
{
if (!Enabled)
{
BasicConsole.SetTextColour(BasicConsole.warning_colour);
BasicConsole.WriteLine("Warning! GC returning null pointer because GC not enabled.");
BasicConsole.DelayOutput(10);
BasicConsole.SetTextColour(BasicConsole.default_colour);
return(null);
}
//try
{
if (length < 0)
{
UART.Write("length < 0. Overflow exception.");
return(null);
//ExceptionMethods.Throw_OverflowException();
}
InsideGC = true;
//Alloc space for GC header that prefixes object data
//Alloc space for new array object
//Alloc space for new array elems
uint totalSize = ((Testing2.Type) typeof(Testing2.Array)).Size;
if (elemType.IsValueType)
{
totalSize += elemType.Size * (uint)length;
}
else
{
totalSize += elemType.StackSize * (uint)length;
}
totalSize += (uint)sizeof(GCHeader);
GCHeader *newObjPtr = (GCHeader *)Heap.AllocZeroed(totalSize, "GC : NewArray");
if ((UInt32)newObjPtr == 0)
{
InsideGC = false;
BasicConsole.SetTextColour(BasicConsole.error_colour);
BasicConsole.WriteLine("Error! GC can't create a new array because the heap returned a null pointer.");
BasicConsole.DelayOutput(10);
BasicConsole.SetTextColour(BasicConsole.default_colour);
return(null);
}
NumObjs++;
//Initialise the GCHeader
SetSignature(newObjPtr);
newObjPtr->RefCount = 1;
Testing2.Array newArr = (Testing2.Array)Utilities.ObjectUtilities.GetObject(newObjPtr + 1);
newArr._Type = (Testing2.Type) typeof(Testing2.Array);
newArr.length = length;
newArr.elemType = elemType;
//Move past GCHeader
byte *newObjBytePtr = (byte *)(newObjPtr + 1);
InsideGC = false;
return(newObjBytePtr);
}
//finally
{
}
}