private unsafe void InitializeHeader(int physicalBufferListSize)
{
int headerSize = HeaderBufferListOffset + IntPtr.Size * physicalBufferListSize;
IntPtr header = MemoryHelpers.AllocateMemory(headerSize);
IntPtr oldHeader = IntPtr.Zero;
MemoryHelpers.Memset(header, headerSize, 0);
// check if an older header exists and copy all data from it to the newly
// allocated header.
if (_serializedDataHeaderSize > 0)
{
Debug.Assert(headerSize > _serializedDataHeaderSize);
Buffer.MemoryCopy((byte *)DBGVISIBLE_serializedDataHeader, (byte *)header, headerSize, _serializedDataHeaderSize);
// mark the older header for deletion
oldHeader = DBGVISIBLE_serializedDataHeader;
}
else
{
// write the serialization format version
*(int *)header = SerializationFormatVersion;
// write the total allocated number of physical buffers (0)
*(int *)(header + sizeof(int)) = 0;
Debug.Assert(_activePhysicalBufferIdx == 0);
}
DBGVISIBLE_serializedDataHeader = header;
_serializedDataHeaderSize = headerSize;
// delete the older header if a new one was allocated
if (oldHeader != IntPtr.Zero)
{
MemoryHelpers.FreeMemory(oldHeader);
}
}